Vitamin D
Cholecalciferol
TL;DR
Vitamin D is a hormone precursor made in skin from sunlight. Supplementation reliably corrects deficiency and modestly reduces acute respiratory infections; claims beyond that are weaker than the popular narrative suggests. Most adults who need it do well on 1000-2000 IU daily with a fat-containing meal.
Ideal For
- People with a measured 25(OH)D below 50 nmol/L
- Anyone living above roughly 40 degrees latitude through winter
- People with darker skin living at high latitude
- Older adults, especially in residential care
- People who are largely indoors or cover their skin
- Those with malabsorption, coeliac disease or after bariatric surgery
Avoid If
- You have hypercalcaemia or primary hyperparathyroidism
- You have sarcoidosis or another granulomatous disease
- You have a history of calcium-containing kidney stones without clinician input
- You are taking high-dose thiazide diuretics plus calcium
- You already exceed 4000 IU daily from combined sources
Frequently Asked Questions
Overview
Vitamin D occupies an unusual place in supplement science: the deficiency state is real, common and easy to correct, while the long list of conditions associated with low vitamin D in observational studies has mostly failed to improve when trials actually gave people the vitamin. That gap matters. Low vitamin D is frequently a marker of poor health rather than a cause of it — people who are unwell spend less time outdoors, and inflammation itself lowers circulating 25(OH)D.
What supplementation does do well is fix a measurable deficiency. Skin synthesis falls with latitude, winter, sunscreen use, darker skin pigmentation, age and indoor work, and dietary sources are thin outside oily fish and fortified foods. Serum 25(OH)D below 30 nmol/L (12 ng/mL) carries a genuine risk of osteomalacia and, in children, rickets; between 30 and 50 nmol/L is generally considered inadequate for bone health.
The large trials of the last decade — VITAL, D-Health, ViDA — tested moderate-to-high doses in largely replete populations and found no reduction in cancer incidence, cardiovascular events or all-cause mortality. Meta-analyses of respiratory infection do show a small protective effect, concentrated in people who were deficient at baseline and who took daily rather than bolus doses. Fracture prevention works when vitamin D is combined with calcium in older adults, particularly in institutional care; vitamin D alone has not shown the same benefit.
The practical reading is straightforward. Correct a deficiency if you have one or are likely to. Do not expect a daily capsule to prevent chronic disease in someone whose levels are already adequate, and be sceptical of very high intermittent dosing, which has performed worse than daily dosing in several trials and increased falls in two.
How It Works
- Cholecalciferol from skin or diet is hydroxylated in the liver to 25(OH)D, the circulating storage form measured on blood tests.
- The kidney converts 25(OH)D to calcitriol, the active hormone, under tight control by parathyroid hormone and FGF23.
- Calcitriol binds the vitamin D receptor, a nuclear transcription factor present in most tissues, altering expression of hundreds of genes.
- Its primary endocrine job is calcium balance: increasing intestinal calcium absorption from roughly 15% to 30-40%, and mobilising bone calcium when intake is low.
- Immune cells convert 25(OH)D locally to calcitriol, which induces antimicrobial peptides such as cathelicidin — the proposed basis for the respiratory infection effect.
- Because it is fat-soluble and stored in adipose tissue, people with higher body fat need larger doses to reach the same serum level.
Quick Facts
- Essential for calcium absorption and bone health
- Supports immune system function and disease resistance
- Acts as a hormone regulating over 1000 genes
- Deficiency affects nearly 1 billion people worldwide
- Can be synthesized by skin exposure to sunlight
Benefits & Outcomes
Viral Load Reduction
Vitamin D deficiency is common in chronic viral infection but correcting it does not lower viral load.
Tendon Strength
Vitamin D deficiency associates with tendon problems, with limited interventional evidence.
Testosterone Support
Vitamin D may raise testosterone in deficient men only, and even that finding is inconsistent.
Tumor Response Rate
Vitamin D has survival signals in some analyses but no effect on tumour response.
Natural Killer Cell Activity
Correcting deficiency supports NK function and cuts respiratory infections.
Pathogen Resistance
Vitamin D sufficiency reduces acute respiratory infection risk, with the benefit concentrated in deficient people taking regular doses.
Post-Illness Recovery
Correcting low vitamin D helps muscle function and immune recovery; supplementing when already replete does nothing.
Pregnancy Support
Vitamin D supplementation in pregnancy is widely recommended, particularly where sun exposure is limited.
Sex Hormone Binding Globulin
Vitamin D relates to androgen status mainly through correcting deficiency, not by moving SHBG.
Shift Work Adaptation
Night workers are a genuinely high-risk group for deficiency because they miss daylight entirely.
Sleep Apnea Symptom Relief
Vitamin D deficiency is common in sleep apnea but correcting it does not treat the apnea.
Sprint Performance
Vitamin D matters if you are deficient and does nothing extra if you are not.
T-Cell Function Enhancement
Vitamin D genuinely modulates T-cell behaviour, with clinical benefit mainly in deficiency.
Sinus Relief
Low vitamin D is associated with chronic rhinosinusitis, but supplementation trials are lacking.
Appetite Regulation
Correcting deficiency may normalise appetite signalling; supplementing beyond repletion does not.
Cytokine Balance
Vitamin D modulates immune signalling but only improves cytokine markers in people who start deficient.
Hair Growth
Correcting vitamin D deficiency supports hair cycling; deficiency is associated with alopecia, but extra D beyond sufficiency has no growth benefit.
Respiratory Health
Vitamin D reduces acute respiratory infections, with the benefit concentrated in deficient people on daily dosing.
Seasonal Mood Support
Vitamin D helps if you are deficient, but it does not replace light therapy for seasonal depression.
Pregnenolone Support
Correcting vitamin D deficiency supports normal steroid hormone production far more predictably than taking precursors.
Respiratory Tract Protection
Vitamin D reduces acute respiratory infections in people who start out deficient.
Scalp Health
Low vitamin D is associated with scalp and hair complaints, but supplementation trials are thin.
Autoimmune Modulation
The VITAL trial showed a genuine reduction in autoimmune disease incidence.
Back Pain Relief
Correcting deficiency may reduce musculoskeletal pain; benefit in replete individuals is unproven.
Bone Mineral Density
Correcting vitamin D deficiency slows bone loss; benefit in replete individuals is modest.
Leptin Sensitivity
Vitamin D is associated with leptin levels observationally but supplementation has not shown a clear effect.
Oxytocin Enhancement
Vitamin D adequacy supports oxytocin-related signalling in animal models, but no human trial shows it changes bonding or social behaviour.
Cancer Survival Rate
Observational links between vitamin D sufficiency and cancer outcomes have not translated into proven survival benefit from supplementation.
Cold Prevention
Vitamin D supplementation reduces acute respiratory infections, with strongest benefit in deficient individuals.
Cold Tolerance
No good evidence that vitamin D improves cold tolerance; its relevance is limited to winter deficiency and general muscle function.
Lung Function
Vitamin D reduces acute respiratory infection risk — with the largest protective effect in people who are deficient — and supports antimicrobial lung defenses.
Macrophage Function
Vitamin D enables macrophage antimicrobial peptide production — deficiency measurably impairs this arm of innate immunity.
Mucosal Immunity
Individual participant meta-analysis (Martineau 2021) shows vitamin D reduces acute respiratory infections, with the largest protection in people who are deficient.
Diabetes Incidence
Test first: repletion helps the deficient; extra D beyond sufficiency does not prevent diabetes.
Fertility Support Female
Test and correct deficiency; more is not better.
Flu Prevention
Real preventive effect for respiratory infections when deficient; vaccination still dominates for flu specifically.
Bone Health Support
Vitamin D supports bone health mainly by correcting deficiency and, with calcium, reducing fracture risk in at-risk groups - high doses in replete adults do not help and may harm.
Immune Function
The best evidence is for respiratory infection prevention: pooled trial data show a small protective effect, concentrated almost entirely in people who were deficient and taking daily rather than bolus doses.
Mood & Mental Health Support
Vitamin D improves mood mainly by correcting deficiency — trials in replete individuals show little benefit, but deficiency-associated low mood responds well.
Mood Stabilization
Observational links between low vitamin D and depression are strong, but randomised trials in people who are not deficient have mostly been negative, including the large VITAL-DEP trial.
Grip Strength Enhancement
Clear benefit if deficient, little if replete.
Muscle Strength & Physical Function
Supplementation improves strength in deficient individuals (below ~20 ng/mL); trials in replete athletes show little added benefit.
Hormonal Balance
Despite vitamin D receptors appearing throughout endocrine tissue, supplementation has not been shown to normalise sex or thyroid hormones in humans.
Health Concerns Addressed
Vitamin D Deficiency
For documented deficiency, daily or weekly vitamin D is the definitive treatment. Avoid large intermittent megadoses, which increased falls and fractures in trials.
Tender Points
Vitamin D deficiency is common in people with widespread musculoskeletal pain and tender points, and correcting deficiency can modestly reduce pain in deficient individuals. It is not a fibromyalgia treatment, but testing is worthwhile.
Chronic Pancreatitis
Straightforward and necessary: deficiency is common, measurable, and correctable. This is repletion, not disease treatment.
Lupus (SLE)
Vitamin D deficiency is nearly universal in lupus patients due to sun avoidance and steroid use, and correcting it is guideline-supported for bone health — though it does not treat the underlying autoimmune disease.
Vertigo Disorder
Likely effective for reducing BPPV recurrence in people with low vitamin D.
Wheezing
Vitamin D supplementation reduces asthma exacerbations in people with low vitamin D levels, which can mean less wheezing over time. It supplements — never replaces — inhalers and prescribed asthma care.
Seasonal Fatigue
Vitamin D levels genuinely fall through winter and deficiency is worth correcting — but trials for seasonal mood and fatigue are mixed, so think of it as sensible groundwork, not the fix. Light is the fix.
Recurring Infections
Vitamin D has the strongest supplement evidence for infection prevention — a 25-trial individual-patient meta-analysis found it reduced respiratory infections, with benefit roughly doubling in people who were deficient.
Autoimmune Disease
Prevention signal in a major trial and near-universal deficiency worth correcting; modest effects once disease is established.
Body Aches
Legitimate and effective when deficiency is the cause — which is common. Useless when levels are already adequate. The test determines everything.
Cushing's Syndrome
Well-supported for the bone complication, useless for the cortisol excess itself. Standard supportive care alongside surgery or steroid tapering.
General Weakness
Genuinely effective when deficiency is documented — and only then.
Inflammatory Bowel Disease
Deficiency is common in IBD and associates with worse disease activity; correcting it is standard care with plausible disease-course benefit.
Type 1 Diabetes
Vitamin D deficiency is more common in people with type 1 diabetes, and maintaining adequate status supports bone and immune health. Crucially, vitamin D does not replace insulin or meaningfully improve blood sugar control in established T1D.
Vitiligo
Vitamin D deficiency is more common in vitiligo, and small studies suggest correcting it may modestly support repigmentation when combined with phototherapy. It's an adjunct to dermatologist-led treatment, not a standalone fix.
Traumatic Brain Injury
Insufficient evidence for recovery; worth correcting a documented deficiency on general grounds.
Alopecia Areata
Correct a documented deficiency on its own merits; do not expect regrowth. The association is real, but causation and treatment benefit are unproven.
Chronic Pain
Deficiency associates strongly with widespread pain, but supplementing people who are already replete does not reduce pain.
Pneumonia
Worth correcting a documented deficiency for general respiratory protection; not a pneumonia therapy.
Morning Fatigue
Worth correcting if deficient, but do not expect it to fix unrefreshing sleep or sleep apnoea.
Ulcerative Colitis
Correct a documented deficiency for bone and general health. Do not expect it to change disease activity.
Breast Cancer
Take it for bones, not to prevent or treat the cancer.
Multiple Sclerosis
Worth maintaining sufficiency given the risk-factor evidence and bone health needs. Not a substitute for disease-modifying therapy, and megadoses are not supported.
Stroke Recovery
Insufficient evidence for recovery; correct deficiency for bone and fall-risk reasons.
Sleep Apnea
Correct deficiency if present, but understand that this does not treat the airway obstruction. CPAP and weight loss remain the interventions that work.
Muscle Weakness
Severe vitamin D deficiency causes a genuine proximal myopathy that reverses on repletion. Supplementing already-adequate levels does not add strength.
Epilepsy
Recommended for anyone on long-term carbamazepine, phenytoin, phenobarbital or primidone. This is bone protection, not seizure control.
Frequent Infections
Worth taking if you are deficient, largely pointless if you are not. Daily vitamin D reduces the odds of an acute respiratory infection by a modest margin, and almost all of that benefit sits in people who started below 25 nmol/L.
Balance Problems
Correcting vitamin D deficiency supports muscle function and may reduce falls; high doses in replete people increase fall risk.
Ear Pain
Modest evidence that correcting deficiency reduces recurrent ear infections in children. No role in treating acute ear pain.
Dizziness
Reasonable for people with recurrent BPPV and low vitamin D. Not a treatment for an active attack, which needs the Epley manoeuvre.
Low Mood & Sadness
Worth testing and correcting if levels are low, particularly through winter. Do not expect a mood effect if your level is already adequate.
Foot Pain
Corrects deficiency-related bone and muscle pain; no role in mechanical foot pain with normal levels.
Chronic Urticaria
Reasonable to test and correct vitamin D if you have chronic urticaria, but keep the antihistamine as the mainstay.
Seasonal Affective Disorder
Correct deficiency for bone and general health, but do not use vitamin D as SAD treatment. Light therapy is the intervention with real evidence.
Menopause
Vitamin D matters for postmenopausal bone health when combined with calcium, but it does not improve hot flashes and monotherapy fracture data are weak.
Celiac Disease
Low vitamin D and reduced bone density are common at celiac diagnosis, and correction is standard care, though it improves bone outcomes rather than digestive symptoms.
Hashimoto's Thyroiditis
Vitamin D deficiency is common in Hashimotos, and correcting it lowers TPO antibody titres in several trials - but antibody reduction has not been shown to change clinical outcomes.
Eczema (Atopic Dermatitis)
Vitamin D supplementation modestly reduces eczema severity in several randomised trials, with the largest benefit in people who are deficient and in those with winter-pattern flares.
Low Testosterone (Male Hypogonadism)
The association between vitamin D status and testosterone is consistent in observational data, but randomised trials are conflicting. Benefit appears limited to men who are genuinely vitamin D deficient.
Shortness of Breath
Reduces exacerbations in COPD and asthma patients who are actually deficient. No benefit in people with adequate vitamin D status.
Chronic Back Pain
Correcting genuine vitamin D deficiency can reduce diffuse musculoskeletal pain, but supplementing people who are already replete does not help back pain.
Psoriasis
Topical vitamin D analogues are a mainstay of psoriasis treatment; oral vitamin D is a different question and the evidence for it is much weaker. Worth correcting a deficiency, but do not substitute a capsule for a prescribed topical.
Unexplained Weight Gain
Low vitamin D is a consequence of higher body fat, not a cause of weight gain. Supplementing does not produce weight loss.
Brain Fog
Vitamin D receptors are widespread in the brain and deficiency is associated with poorer cognitive performance, but supplementation trials in people who are already replete show little benefit. Worth testing status rather than supplementing blindly.
Chronic Fatigue
Only worth trying if your vitamin D is actually low. Correcting a real deficiency can lift fatigue substantially; supplementing on top of an adequate level does nothing, and most fatigue has another cause.
Thyroid Disorders
Vitamin D deficiency is more prevalent in autoimmune thyroid disease and correction lowers antibody levels, but supplementation is not a treatment for hypo- or hyperthyroidism.
Endometriosis
Low vitamin D status is associated with endometriosis severity, and small trials report reduced pelvic pain with supplementation — but lesion outcomes are untested.
Supporting Research194 studies
Adjunctive nutraceuticals for depression: a systematic review and meta-analyses
Sarris J, Murphy J, Mischoulon D
Strongest adjunctive evidence for omega-3 (SMD 0.61), SAMe, methylfolate and vitamin D; mixed or negative results for zinc, folic acid and inositol.
Magnesium, vitamin D status and mortality: results from US National Health and Nutrition Examination Survey (NHANES) 2001 to 2006 and NHANES III
Deng X, et al.
Magnesium intake alone or its interaction with vitamin D intake may contribute to vitamin D status.
A high whey protein, vitamin D and E supplement preserves muscle mass, strength, and quality of life in sarcopenic older adults: A double-blind randomized controlled trial
Bo Y, Liu C
The supplement preserved muscle mass and strength and improved anabolic markers versus control.
Modifiable prognostic factors in uterine fibroid development: a systematic review of literature
Diet, vitamin D status, obesity and smoking were identified as modifiable factors influencing fibroid development.
Choline-stabilized orthosilicic acid supplementation as an adjunct to calcium/vitamin D3 stimulates markers of bone formation in osteopenic females: a randomized, placebo-controlled trial
Spector TD, Calomme MR, Anderson SH
Bone formation marker PINP rose significantly in the 6 and 12 mg silicon arms; femoral and lumbar BMD changes did not reach significance.
Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis
Bolland MJ, Avenell A, Baron JA +4 more
Calcium supplements without co-administered vitamin D were associated with an approximately 30% increased risk of myocardial infarction in pooled patient-level analysis.
Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline
Holick MF, Binkley NC, Bischoff-Ferrari HA +2 more
The guideline defines deficiency as 25(OH)D below 20 ng/mL and insufficiency as 21-29 ng/mL, recommends 600-800 IU/day as a dietary minimum for bone health, and notes that 1,500-2,000 IU/day may be needed for adults to exceed 30 ng/mL. Screening is recommended only for at-risk groups, and the tolerable upper limit for adults is set at 4,000 IU/day (up to 10,000 IU/day under supervision for correcting deficiency).
Vitamin and mineral deficiencies are highly prevalent in newly diagnosed celiac disease patients
Wierdsma NJ, van Bokhorst-de van der Schueren MA, Berkenpas M
Deficiencies of iron (28%), vitamin B12 (19%), folate, zinc (67% below reference) and vitamin D were common before treatment.
Effect of Vitamin D Supplementation on Improving Glucose Homeostasis in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis
Zhang Y, Tan H, Tang J +8 more
Pooled randomized trial data show vitamin D supplementation modestly improves fasting glucose, HbA1c and insulin resistance (HOMA-IR) in people with type 2 diabetes, with the clearest effects in participants who were vitamin D deficient at baseline and with higher-dose or shorter-interval regimens.
The Role of Vitamins and Minerals in Hair Loss: A Review
Almohanna HM, Ahmed AA, Tsatalis JP +1 more
Evidence supports correcting documented iron, zinc and vitamin D deficiency, but there is no good evidence that biotin or routine micronutrient supplementation stimulates hair growth in people without deficiency.
Effects of a Vitamin D and Leucine-Enriched Whey Protein Nutritional Supplement on Measures of Sarcopenia in Older Adults, the PROVIDE Study: A Randomized, Double-Blind, Placebo-Controlled Trial
Bauer JM, Verlaan S, Bautmans I +3 more
The active supplement group showed significant improvements in handgrip strength and Short Physical Performance Battery score versus control
Effect of Vitamin D on Depression: A Randomized Clinical Trial
Okereke OI, Reynolds CF, Mischoulon D +1 more
In the VITAL-DEP ancillary trial of 18,353 adults aged 50+, vitamin D3 2,000 IU/day did not reduce the risk of incident depression or clinically relevant depressive symptoms compared with placebo (HR 0.97) and produced no meaningful difference in mood scores over a median 5.3 years.
The Roles of Vitamin D in Skeletal Muscle: Form, Function, and Metabolism
Girgis CM, Clifton-Bligh RJ, Hamrick MW +2 more
Severe vitamin D deficiency causes proximal myopathy with type II (fast-twitch) fibre atrophy that improves with repletion. Observational data link low 25(OH)D with reduced strength and higher fall risk in older adults. Supplementation trials show benefit mainly in deficient and older populations, particularly for falls reduction; trials in replete adults and athletes show little or no strength gain. Direct genomic and non-genomic vitamin D receptor signalling in muscle is supported, though rece
Vitamin D Supplementation and Major Cardiovascular Events: D-Health Randomized Controlled Trial
Neale RE, Baxter C, Romero BD +12 more
Major cardiovascular events occurred in 6.0% of the vitamin D group versus 6.6% of placebo (HR 0.91, 95% CI 0.81-1.01) - a difference that did not reach statistical significance. Rates of myocardial infarction (HR 0.81) and coronary revascularisation (HR 0.89) were lower in the vitamin D group, while stroke rates were similar. Absolute risk difference was about 5.8 fewer events per 1,000 participants.
Effects of different supplements on Hashimoto's thyroiditis: a systematic review and network meta-analysis
Selenium reduced TPOAb and TgAb; myo-inositol, vitamin D alone and Se+myo-inositol did not significantly reduce antibodies over 6 months.
Prevalence of vitamin D deficiency in Africa: a systematic review and meta-analysis
Mogire RM, Mutua A, Kimita W +1 more
Across 119 studies covering 21,474 participants in 23 African countries, pooled prevalence of 25(OH)D below 30 nmol/L was 18.5%, below 50 nmol/L was 34.2% and below 75 nmol/L was 59.5%. Deficiency was more common in northern Africa, in urban populations, in women and in those with less sun exposure or greater skin covering.
Vitamin D Supplementation and Muscle Strength: A Meta-Analysis
Stockton KA, Mengersen K, Paratz JD +2 more
In participants with baseline serum 25(OH)D above 25 nmol/L, vitamin D supplementation produced no significant improvement in grip strength or proximal lower limb strength. In the subgroup with baseline 25(OH)D below 25 nmol/L, supplementation significantly increased hip muscle strength (standardised mean difference 3.52).
Impact of micronutrient deficiency & malnutrition in systemic sclerosis: Cohort study and literature review
Dupont R, Longue M, Galinier A +1 more
A cohort study with accompanying literature review found micronutrient deficiencies were common in systemic sclerosis - most frequently vitamin D, selenium, zinc, vitamin B9/B12 and iron - and clustered with malnutrition, gastrointestinal involvement and worse disease severity scores.
Clinical Efficacy of Vitamin D3 Adjuvant Therapy in Allergic Rhinitis: A Randomized Controlled Trial
Liu Z
Adding vitamin D3 to standard antihistamine/intranasal steroid therapy in allergic rhinitis produced greater reductions in nasal symptom scores and in serum IgE and Th2-associated cytokines than standard therapy alone, with the largest benefit in patients who were vitamin D deficient at baseline.
Boron and bone health: a systematic review
Hunt, C.D.
This review of human and animal data found boron influences calcium, magnesium and vitamin D metabolism and steroid hormone levels, with depletion-repletion studies suggesting boron may reduce urinary calcium loss, but no clinical trials demonstrating reduced fracture risk or improved bone mineral density in humans.
Vitamin D and Calcium: A Systematic Review of Health Outcomes
Chung M, Lee J, Terasawa T +2 more
This AHRQ-derived evidence review found that vitamin D combined with calcium modestly reduces fracture risk in institutionalised older adults, while evidence for vitamin D alone and for non-skeletal outcomes (cancer, cardiovascular disease, immune function) was inconsistent and largely inconclusive. Serum 25(OH)D thresholds for these outcomes could not be established.
Vitamin D and the Immune System: New Perspectives on an Old Theme
Aranow C
Vitamin D receptors are expressed on monocytes, macrophages, dendritic cells and T and B lymphocytes; calcitriol upregulates antimicrobial peptides such as cathelicidin, dampens Th1/Th17 responses and promotes regulatory T cells. Deficiency is associated with autoimmune disease and infection risk in observational data.
Vitamin D and Muscle Function in Older Adults
Bischoff-Ferrari HA, Dawson-Hughes B, Orav EJ +1 more
This review of trials and observational data concluded that vitamin D acts on skeletal muscle via the vitamin D receptor, that low 25(OH)D is associated with reduced muscle strength, more body sway and higher fall risk in older adults, and that supplementation of roughly 700-1000 IU/day improves balance and reduces falls by around 19%, with little benefit at lower doses.
Association Between Serum Trace Elements Level and Alopecia Areata: A Systematic Review and Meta-Analysis
Wu R
Pooled case-control data showed patients with alopecia areata had significantly lower serum vitamin D and zinc concentrations than controls, while other trace elements showed no consistent association.
Low vitamin D levels in healthy controls and patients with autoimmune neuromuscular disorders in Greece
Chroni E, et al
Serum 25(OH)D was low in both autoimmune neuromuscular patients and healthy Greek controls, with no significant difference between groups and no correlation between vitamin D level and myasthenia gravis severity or disease duration.
Pivotal role of boron supplementation on bone health: A narrative review
Rondanelli M, Faliva MA, Peroni G +1 more
Available human studies suggest boron influences calcium, magnesium and vitamin D metabolism relevant to bone, but no dosing recommendation can be established from current data.
Vitamin D Supplementation and Prevention of Type 2 Diabetes (D2d)
Vitamin D3 supplementation at a dose of 4000 IU per day did not result in a significantly lower risk of diabetes than placebo.
The Effects of Vitamin D on Skeletal Muscle Strength, Muscle Mass, and Muscle Power: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Beaudart C, Buckinx F, Rabenda V +3 more
There is growing evidence that vitamin D plays a role on several tissues including skeletal muscle.
Effects of Vitamin D Supplementation on Cognitive Function in Older Adults: A GRADE Methodology-Assessed Systematic Review and Meta-Analysis of Randomized Clinical Trials
Behrouzi R, et al.
While no significant enhancement in the domains of executive function, attention, and perceptual speed was found.
Effects of vitamin D supplementation on depression and some selected pro-inflammatory biomarkers: a double-blind randomised clinical trial
Effects of vitamin D supplementation on depression and some selected pro-inflammatory biomarkers: a double-blind randomised clinical trial.
Effects of selected dietary supplements on migraine prophylaxis: A systematic review and dose-response meta-analysis of randomized controlled trials
Talandashti MK, Shahinfar H, Delgarm P +1 more
Magnesium supplementation reduced migraine attacks (mean difference (MD) = -2.51), severity (MD = -0.88), and the monthly migraine days (MD = -1.66) compared with the control group.
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
Martineau AR, Jolliffe DA, Hooper RL +3 more
Vitamin D reduced acute respiratory infection risk overall, with the largest benefit in deficient participants
Effect of Oral Consumption of Vitamin D on Uterine Fibroids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials
Vitamin D supplementation significantly reduced uterine fibroid volume in pooled randomized clinical trials.
Effects of Vitamin D3 and Marine Omega-3 Fatty Acids Supplementation on Biomarkers of Systemic Inflammation: 4-Year Findings from the VITAL Randomized Trial
Dong Y, Zhu H, Chen L
Vitamin D3 supplementation decreased serum hs-CRP levels by 19% at 2-year follow-up, but not at 4-year follow-up.
Dietary supplements for preventing postnatal depression
Miller BJ, Murray L, Beckmann MM +1 more
To assess the benefits of dietary supplements for preventing postnatal depression either in the antenatal period, postnatal period, or both.
Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial
Hahn J, Cook NR, Alexander EK
Vitamin D reduced confirmed incident autoimmune disease by 22% (HR 0.78).
Antioxidant vitamins supplementation reduce endometriosis related pelvic pain in humans: a systematic review and meta-analysis
Zheng SH, Chen XX, Chen Y +3 more
antioxidant vitamins supplementation reduce endometriosis related pelvic pain in humans
Beneficial role for supplemental vitamin D3 treatment in chronic urticaria: a randomized study
Rorie A, Goldner WS, Lyden E +1 more
Triple-drug therapy decreased total USS scores by 33% in the first week. There was a further significant decrease (40%) in total USS scores in the high, but not low, vitamin D3 treatment group by week 12.
Updated Meta-analysis Reveals Limited Efficacy of Vitamin D Supplementation in Chronic Low Back Pain
Lee TJ, Tsai RY, Ho CC +2 more
The results indicated that vitamin D supplementation did not significantly reduce pain scores compared to control groups (SMD: -0.130, 95%CI=-0.260 to 0.000).
Combined Rehabilitation with Alpha Lipoic Acid, Acetyl-L-Carnitine, Resveratrol, and Cholecalciferol in Discogenic Sciatica in Young People: A Randomized Clinical Trial
Scaturro D, Vitagliani F, Tomasello S +3 more
This prospective study aims to evaluate the effectiveness of a rehabilitation program combined with the administration of Alpha Lipoic Acid, Acetyl-L-Carnitine, Resveratrol, and Cholecalciferol in the treatment of sciatica due to herniated discs in young patients.
Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials
Jolliffe DA, Camargo CA, Sluyter JD +1 more
Protection was associated with administration of daily doses of 400-1000 IU for up to 12 months, and age at enrolment of 1.00-15.99 years.
Effects of Serum Vitamin D Levels and Vitamin D Supplementation on Urticaria: A Systematic Review and Meta-Analysis
Li Y, Cao Z, Guo J +2 more
Six VitD supplementation trials showed a significant reduction in clinical urticarial score on intervention with VitD.
Effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis: a randomized controlled trial
McAlindon T, et al
Vitamin D supplementation for 2 years, when compared with placebo, did not reduce knee pain or cartilage volume loss in patients with symptomatic knee OA.
Vitamin D for the management of multiple sclerosis
Jagannath VA, et al
To date, very low-quality evidence suggests no benefit of vitamin D for patient-important outcomes among people with MS.
Effect of Vitamin D Supplementation on Psoriasis Severity in Patients With Lower-Range Serum 25-Hydroxyvitamin D Levels: A Randomized Clinical Trial
Jenssen M, Furberg AS, Jorde R +2 more
This randomized, double-blind placebo-controlled clinical trial ... Adults from the general population in Tromsø with active plaque psoriasis and 25-hydroxyvitamin D (25[OH]D) levels of less than 24 ng/mL were included.
Association between vitamin D supplementation and mortality: systematic review and meta-analysis
Zhang Y, et al
Vitamin D supplementation reduced the risk of cancer death by 16%.
Effects of vitamin D on patients with fibromyalgia syndrome: a randomized placebo-controlled trial
Wepner F
Optimization of calcifediol levels in FMS had a positive effect on the perception of pain.
Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease (VITAL)
Manson JE, Cook NR, Lee IM
Supplementation with vitamin D did not result in a lower incidence of major cardiovascular events than placebo.
Vitamin D supplementation to prevent asthma exacerbations: an updated systematic review and meta-analysis
Jolliffe DA, Stefanidis C, Wang Z
Vitamin D did not reduce the rate of asthma exacerbations requiring systemic corticosteroids overall.
Vitamin D supplementation decrease asthma exacerbations in children: a systematic review and meta-analysis of randomized controlled trials
Vitamin D supplementation reduced asthma exacerbation rates in children compared with placebo.
The influence of vitamin D supplementation on IGF-1 levels in humans: A systematic review and meta-analysis
Ameri P, Giusti A
Vitamin D supplementation produced a small but significant increase in circulating IGF-1
Effects of vitamin D supplementation on autoantibodies and thyroid function in patients with Hashimoto's thyroiditis: A systematic review and meta-analysis
Vitamin D supplementation may have beneficial effects on HT patients by modulating immune responses and improving thyroid function.
The effect of vitamin D supplementation in treatment of children with autism spectrum disorder: a systematic review and meta-analysis of randomized controlled trials
Li B, Xu Y, Zhang X +2 more
Vitamin D supplementation indicated a small but significant improvement in hyperactivity scores.
Association between serum vitamin D and chronic rhinosinusitis: a meta-analysis
Li B, Wang M, Zhou L +2 more
The outcomes were presented as Weighted Mean Difference combined with 95% Confidence Intervals to estimate the difference of serum vitamin D levels between patients with chronic rhinosinusitis and controls.
Randomized trial of vitamin D supplementation for winter-related atopic dermatitis in children
Camargo CA Jr
Vitamin D supplementation improved winter-related AD among Mongolian children, a population likely to have vitamin D deficiency in winter.
The Effect of Vitamin D Supplement Consumption on Premenstrual Syndrome in Vitamin D-Deficient Young Girls: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial
Abdollahi R, Abiri B, Sarbakhsh P +2 more
It seems that 2,000 IU vitamin D consumption in the vitamin D-deficient young girls with PMS every other day for 12 weeks had no significant impact on other PMS symptoms.
Vitamin D insufficiency is associated with challenge-proven food allergy in infants
Allen KJ, Koplin JJ, Ponsonby AL +4 more
Vitamin D insufficient infants were three times more likely to have challenge-proven food allergy.
Safety and Effectiveness of Oral Nutraceuticals for Treating Acne: A Systematic Review
Shields A, Ly S, Wafae B +7 more
This systematic review suggests a possible role for nutraceutical supplements in the treatment of acne.
High prevalence of osteoporosis in patients with chronic pancreatitis: a systematic review and meta-analysis
Duggan SN, Smyth ND, Murphy A
Around 65% of patients with chronic pancreatitis had osteopenia or osteoporosis, linked to fat malabsorption and low vitamin D.
Effect of vitamin D supplementation on pain: a systematic review and meta-analysis
Wu Z, Malihi Z, Stewart AW
Vitamin D produced a small reduction in mean pain score, mainly in deficient participants.
Individual and additive effects of vitamin D, omega-3 and exercise on DNA methylation clocks of biological aging in older adults from the DO-HEALTH trial
Bischoff-Ferrari HA, Gangler S, Wieczorek M
all three treatments had additive benefits on PhenoAge
Epidemiological and investigative study of premature graying of hair in higher secondary and pre-university school children
Bhat RM
S. Ca, S. Ferritin, vitamin D3 may play a role in premature graying of hair.
A review of the neuroprotective role of vitamin D in traumatic brain injury with implications for supplementation post-concussion
Lawrence DW
VDH supplementation cannot be recommended at this time to improve outcomes following TBI.
Vitamin D supplementation for patients with dry eye syndrome refractory to conventional treatment
Bae SH, Shin YJ, Kim HK +3 more
Vitamin D supplementation improved tear break-up time and Ocular Surface Disease Index scores in patients refractory to conventional treatment.
Vitamin D status, aeroallergen sensitization, and allergic rhinitis: a systematic review and meta-analysis
Aryan Z, Rezaei N, Camargo CA
Low vitamin D status was associated with allergic rhinitis in children.
Vitamin D supplementation in pregnant women or infants for preventing allergic diseases: a systematic review and meta-analysis of randomized controlled trials
Luo C
Supplementation of vitamin D in pregnant women or infants does not have an effect on the primary prevention of allergic diseases.
The link between vitamin D metabolism and sleep medicine
McCarty DE, Chesson AL, Jain SK +1 more
Low 25-hydroxyvitamin D was associated with excessive daytime sleepiness.
Self-reported sleep bruxism is associated with vitamin D deficiency and low dietary calcium intake: a case-control study
Alkhatatbeh MJ
Sleep bruxism was associated with vitamin D deficiency and low consumption of calcium and was also associated with increased scores of anxiety and depression.
Vitamin D and Hyperkinetic Movement Disorders: A Systematic Review
Low vitamin D status was associated with hyperkinetic movement disorders, without interventional evidence of tremor benefit.
Bones of contention: bone mineral density recovery in celiac disease - a systematic review
Grace-Farfaglia P
Calcium and vitamin D repletion supports but does not replace gluten-free adherence for bone recovery.
Mean Platelet Volume, Vitamin D and C Reactive Protein Levels in Normal Weight Children with Primary Snoring and Obstructive Sleep Apnea Syndrome
Zicari AM
The present study provides evidence of higher MPV and lower vitamin D levels in children with PS as well as in children with OSAS, and supports the underlying inflammation.
New Insight into the Role of Vitamin D in the Stroke Risk: A Meta-Analysis of Stratified Data by 25(OH)D Levels
Fusaro M, De Caterina R, Tripepi G
an original meta-analysis stratified by population mean levels of 25(OH)D
Serum Levels of 25-Hydroxyvitamin D in Patients with Seborrheic Dermatitis: A Case-Control Study
Rahimi S
The 25(OH)D values are significantly lower in seborrheic dermatitis patients than in healthy subjects.
Vitamin D supplementation and risk of acute respiratory tract infection: systematic review and meta-analysis
Martineau, A.R., Jolliffe, D.A., Hooper, R.L.
Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants.
Vitamin D and obstructive sleep apnea: a systematic review and meta-analysis
Neighbors CLP, Noller MW, Song SA +1 more
There was a relative insufficiency in serum 25(OH)D levels among OSA patients compared to control patients, which was incrementally exacerbated with increasing severity of sleep apnea
Effects of Vitamin D Supplementation on Insulin Sensitivity and Secretion in Prediabetes
Treatment with vitamin D3 for 24 months did not improve an OGTT-derived index of beta-cell function in people with prediabetes.
Is There an Association Between Vitamin D Deficiency and Erectile Dysfunction? A Systematic Review and Meta-Analysis
Crafa A, et al.
this meta-analysis suggests an association between vitamin D deficiency and the presence of severe forms of ED, independent of testicular function.
Efficacy of vitamin D3 supplementation on cancer mortality: systematic review and individual patient data meta-analysis of randomised controlled trials
Kuznia S, et al
A subgroup analysis revealed that vitamin D3 administered daily, in contrast to bolus supplementation, reduced cancer mortality by 12%.
Effect of vitamin D supplementation on depression in older Australian adults
Rahman ST, et al
Monthly supplementation with high-dose vitamin D3 was not of benefit for measures of depression overall, but there was some evidence of benefit in subgroup analyses.
Vitamin D Supplementation for Patients with Dysmenorrhoea: A Meta-Analysis with Trial Sequential Analysis of Randomised Controlled Trials
Lin KC, Huang KJ, Lin MN +1 more
Vitamin D supplementation significantly decreased pain intensity in patients with dysmenorrhoea compared with controls.
Nutritional Interventions in Adult Patients With Irritable Bowel Syndrome: An Umbrella Review of Systematic Reviews and Meta-analyses of Randomized Clinical Trials
Zeraattalab-Motlagh S, Ranjbar M, Mohammadi H +1 more
soluble fiber, peppermint oil, and aloe vera improved IBS symptoms, and vitamin D3 and curcumin improved IBS symptom severity
Supplementation with vitamin D or omega-3 fatty acids in adolescent girls and young women with endometriosis (SAGE): a double-blind, randomized, placebo-controlled trial
Nodler JL, DiVasta AD, Vitonis AF +3 more
Participants in the vitamin D arm experienced significant improvement in VAS pain
Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren
Influenza A occurred in 10.8% of children in the vitamin D3 group compared with 18.6% in the placebo group.
The effect of vitamin D supplementation on survival in patients with colorectal cancer: systematic review and meta-analysis of randomised controlled trials
Vaughan-Shaw PG, Buijs LF, Blackmur JP +2 more
meta-analysis found a 30% reduction in adverse CRC outcomes with supplementation (n = 815, HR = 0.70; 95% confidence interval (CI): 0.48-0.93)
Vitamin D in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After COVID-19 or Vaccination: A Randomized Controlled Trial
Kodama T, et al
Vitamin D replacement therapy guidance significantly reduced ME/CFS symptoms along with improvement of serum 25(OH) vitamin D levels in patients with vitamin D insufficiency or deficiency.
Chronic urticaria and vitamin D supplementations: a systematic review
Siddiqui A, Bai A, Kumar H +6 more
High-dose regimens (e.g., 4,000 IU/day or 60,000 IU/week) appeared more effective.
Effectiveness of oral vitamin D supplementation in lessening disease severity among patients with psoriasis: A systematic review and meta-analysis of randomized controlled trials
Theodoridis X, Grammatikopoulou MG, Stamouli EM +5 more
Vitamin D supplementation was effective in ameliorating the PASI score after 6 mo of intervention (mean difference [MD] = -0.92, 95% CI = -1.72 to -0.11). However, after the Hartung-Knapp adjustment, the results became non-significant.
Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis
Bolland MJ, Grey A, Avenell A
Vitamin D supplementation did not prevent falls or fractures or produce clinically meaningful bone density improvement.
Chronic urticaria merits serum vitamin D evaluation and supplementation; a randomized case control study
Rasool R, Masoodi KZ, Shera IA +5 more
Vit-D3 supplementation in combination with antihistamine and systemic corticosteroid show elevated response in resolving the symptoms of CU.
Updated Meta-Analysis on Vitamin Supplementation for Chronic Pruritus: Expanding Evidence Beyond Vitamin D
Kuo WH, et al.
Subgroup analysis revealed that topical vitamin B12 and vitamin D3 showed the most pronounced antipruritic effects, particularly in patients with atopic dermatitis and chronic kidney disease-associated pruritus.
The efficacy of vitamin D in multiple sclerosis: A meta-analysis
Zheng C, et al
Our findings suggest that vitamin D appeared to have no therapeutic effect on EDSS score or ARR in the patients with MS.
Efficacy of vitamin D replacement therapy in restless legs syndrome: a randomized control trial
Wali SO
The results suggest that vitamin D supplementation does not improve restless legs syndrome symptoms.
A Systematic Review of Vitamin D and Fibroids: Pathophysiology, Prevention, and Treatment
Vitamin D deficiency is associated with fibroid development, with antifibrotic mechanisms shown in leiomyoma cells.
Effect of vitamin D supplementation on benign paroxysmal positional vertigo recurrence: A meta-analysis
Vitamin D supplementation significantly reduced recurrence of benign paroxysmal positional vertigo in pooled analysis.
Vitamin D supplementation for women during pregnancy
Palacios C, Kostiuk LK, Pena-Rosas JP
Vitamin D probably reduces pre-eclampsia, gestational diabetes and low birthweight
Effect of Dietary Interventions on Endometriosis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Meneghetti JK, Pedrotti MT, Coimbra IM +1 more
antioxidant use was associated with a reduction in dysmenorrhea (mean difference - 1.95 [CI 95%, -3.78 to -0.13]
Clinical trial: vitamin D3 treatment in Crohn's disease - a randomized double-blind placebo-controlled study
Jorgensen SP, Agnholt J, Glerup H
The relapse rate was 13% in the vitamin D3 group versus 29% in the placebo group (P = 0.06).
Vitamin D to prevent exacerbations of COPD: systematic review and meta-analysis of individual participant data
Jolliffe DA, Greenberg L, Hooper RL
Vitamin D reduced moderate-to-severe exacerbation rates in participants with baseline 25(OH)D below 25 nmol/L.
Vitamin D levels in systemic sclerosis patients: a meta-analysis
An L, Sun MH, Chen F +1 more
SSc patients exhibited lower vitamin D levels compared with healthy controls. Vitamin D levels in diffused-type SSc patients were significantly lower than those in limited-type SSc patients. The severity of clinical features was not associated with the extent of vitamin D deficit.
Nutritional supplements and cognition in healthy aging and mild cognitive impairment patients: a systematic review and network meta-analysis
Liu X
DHA alone was found to be beneficial in improving processing speed, whereas vitamin D3 was associated with improvements in visuospatial function.
Vitamin D and Beta Cells in Type 1 Diabetes: A Systematic Review
Vitamin D showed immunomodulatory effects on beta cells in type 1 diabetes, with inconsistent clinical benefit.
Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life in sarcopenic elderly
Rondanelli M, Klersy C
Whey protein, essential amino acids and vitamin D increased IGF-1 alongside fat-free mass in sarcopenic elderly
Antiepileptic drugs and bone health: vitamin D and fracture risk
Lee RH, Lyles KW, Colon-Emeric C
Enzyme-inducing antiepileptic drugs increase vitamin D catabolism and are associated with reduced bone mineral density.
Vitamin D supplementation reduces the risk of acute otitis media in otitis-prone children
Marchisio P, Consonni D, Baggi E +5 more
Vitamin D supplementation significantly reduced the number of episodes of uncomplicated acute otitis media.
Preventing food allergy in infancy and childhood: Systematic review of randomised controlled trials
Vitamin D supplementation in pregnancy or infancy did not consistently prevent allergic disease or wheeze.
Posttraumatic stress disorder is associated with reduced vitamin D levels and functional polymorphisms of the vitamin D binding-protein in a population-based sample
Terock J
25(OH)D levels were inversely and vitamin D deficiency positively associated with PTSD.
Vitamin D supplementation and disease activity in patients with immune-mediated rheumatic diseases: a systematic review and meta-analysis
Franco AS, Freitas TQ, Bernardo WM
No consistent improvement in disease activity with vitamin D in autoimmune rheumatic disease.
Exploration of potential lipid biomarkers for premature canities by UPLC-QTOF-MS analyses of hair follicle roots
Wang H
VD3 showed a substantial decrease in white hair and was a potential target for further studies.
Vitamin D levels in patients with seborrheic dermatitis
Akbas A
The fact that vitamin D levels decreased in patients with seborrheic dermatitis suggests that the low levels of vitamin D are related to seborrheic dermatitis.
Comparative evaluation of the effects of diclofenac sodium and vitamin D supplementation on symptoms in individuals with myofascial pain and vitamin D deficiency: a randomized controlled clinical trial
Vitamin D may serve as an alternative with anti-inflammatory and analgesic effects compared to NSAIDs.
Vitamin D and Depression: A Critical Appraisal of the Evidence and Future Directions
Anglin RE, Samaan Z, Walter SD +1 more
Critical review examining the relationship between vitamin D status and depression, including potential mechanisms and clinical implications.
Vitamin D Improves Selected Metabolic Parameters but Not Neuropsychological or Quality of Life Indices in OSA: A Pilot Study
Kerley CP, Hutchinson K, Bramham J +1 more
Although there was no change in neuropsychological or quality of life indices, we observed a significant increase in 25(OH)D and significant decreases in both low-density lipoprotein and lipoprotein-associated phospholipase A2
Effect of vitamin D supplementation on all-cause mortality: a meta-analysis of randomized controlled trials
Zhang Y, Fang F, Tang J +3 more
Vitamin D supplementation did not reduce all-cause mortality overall
Effect of Vitamin D Supplementation, Omega-3 Fatty Acid Supplementation, or a Strength-Training Exercise Program on Clinical Outcomes in Older Adults: The DO-HEALTH Randomized Clinical Trial
Bischoff-Ferrari HA, Vellas B, Rizzoli R
vitamin D3, omega-3s, or a strength-training exercise program did not result in statistically significant differences in improvement in ... physical performance
The effect of vitamin D add-on therapy on the improvement of quality of life and clinical symptoms of patients with chronic spontaneous urticaria
Nabavizadeh SH, Alyasin S, Esmaeilzadeh H +2 more
Quality of life score was also significantly reduced; decrement in group 2 score was significant compared to group 1 at both weeks 6 (P = 0.005) and 12 (P = 0.007).
Hypercalcemia, hypercalciuria, and kidney stones in long-term studies of vitamin D supplementation: a systematic review and meta-analysis
Malihi Z, Wu Z, Stewart AW +2 more
Long-term vitamin D supplementation resulted in increased risks of hypercalcemia and hypercalciuria, which were not dose related. However, vitamin D supplementation did not increase risk of kidney stones.
Effect of vitamin D supplementation on various parameters in patients with non-alcoholic fatty liver disease: An updated meta-analysis
Li D, Fu N, Wu H
However, no significant differences were found in terms of triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), c-glutamyltransferase, fasting blood glucose (FBG), homeostasis model assessment of insulin resistance (HOMA-IR)
Effects of vitamin D supplementation on upper and lower body muscle strength levels in healthy individuals. A systematic review with meta-analysis
Tomlinson PB, et al.
Vitamin D supplementation increases upper and lower limb strength. Further research should focus on its effect on muscle power, endurance and maximal strength.
Vitamin D association with systemic sclerosis and its clinical features: A systematic review, meta-analysis, and meta-regression
Dhaouadi T, Riahi A, Ben Abdallah T +2 more
This meta-analysis showed that decreased Vitamin D level was associated with susceptibility to systemic sclerosis, interstitial lung disease occurrence, increased systolic pulmonary arterial pressure, and higher modified Rodnan skin score. Conversely, calcinosis was found to be associated with increased Vitamin D level.
The effect of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis
Mehdizadehkashi A, Rokhgireh S, Tahermanesh K +3 more
Vitamin D supplementation significantly decreased pelvic pain (beta - 1.12; 95% CI, -2.1, -0.09; p=.03)
Effect of Vitamin D Supplementation on Primary Dysmenorrhea: A Systematic Review and Meta-Analysis of Randomized Clinical Trials
Chen YC, et al.
The results revealed that vit. D treatment substantially reduced the pain level in the primary dysmenorrhea population.
Association between vitamin D deficiency and benign paroxysmal positional vertigo (BPPV) incidence and recurrence: a systematic review and meta-analysis
Vitamin D deficiency was associated with both incidence and recurrence of benign paroxysmal positional vertigo.
Effects of nutritional interventions on the severity of depressive and anxiety symptoms of women in the menopausal transition and menopause: a systematic review, meta-analysis, and meta-regression
Grigolon RB, Ceolin G, Deng Y +1 more
The pooled effect size favored the intervention group over placebo for both DS and AS (DS: standardized mean difference, -0.35 [95% confidence interval, -0.68 to -0.03; P = 0.0351])
Effect of nutritional interventions on the psychological symptoms of premenstrual syndrome in women of reproductive age: a systematic review of randomized controlled trials
Robinson J, Ferreira A, Iacovou M +1 more
To date, high-quality research investigating the effects of dietary and nutrient intervention on PMS is limited.
Vitamin D and Insulin-Dependent Diabetes: A Systematic Review of Clinical Trials
Vitamin D supplementation in insulin-dependent diabetes produced inconsistent effects on HbA1c and insulin requirements.
Effect of vitamin D supplementation on uterine fibroids: a meta-analysis of the literature
Vitamin D supplementation was associated with reduced fibroid size across the meta-analysed literature.
A randomized trial of vitamin D supplementation to prevent seasonal influenza and enterovirus infection in children
Vitamin D supplementation did not significantly reduce the incidence of influenza and enterovirus infection in Taiwanese children.
Light therapy and vitamin D for seasonal affective disorder: a systematic review
Nussbaumer-Streit B, Forneris CA, Morgan LC +3 more
Evidence for vitamin D in preventing winter depression was of very low quality
The effect of Vitamin D and calcium plus Vitamin D on leg cramps in pregnant women: A randomized controlled trial
Mansouri A, et al
The results of this study showed that the calcium-Vitamin D and the Vitamin D supplements have no effect on the frequency, length, and pain intensity of leg cramps during the 6 weeks of the study.
Bisphosphonates for steroid-induced osteoporosis
Allen CS, Yeung JH, Vandermeer B
Bisphosphonates, with calcium and vitamin D, increase bone mineral density and reduce vertebral fractures in patients receiving glucocorticoids.
Is Serum Vitamin D Associated with Depression or Anxiety in Ante- and Postnatal Adult Women? A Systematic Review with Meta-Analysis
Centeno LOL, Fernandez MDS, Muniz FWMG +1 more
Based on very low/low-quality evidence, it was observed that reduced serum 25[OH]D concentrations in the ante- and postnatal period are associated with the presence of ante- and postnatal depressive symptoms, respectively.
Fall prevention with supplemental and active forms of vitamin D: a meta-analysis of randomised controlled trials
Bischoff-Ferrari HA, Dawson-Hughes B, Staehelin HB
Doses of 700-1000 IU/day reduced falls by 19%.
Oral vitamin D3 supplementation for chronic plaque psoriasis: a randomized, double-blind, placebo-controlled trial
Ingram MA, Jones MB, Stonehouse W +4 more
A direct benefit of vitamin D3 supplementation for psoriasis could not be determined.
Obstructive sleep apnea and vitamin D: an updated systematic review and meta-analysis
Loh HH
Patients with OSA have lower serum 25-OHD levels with a higher prevalence of vitamin D deficiency, regardless of age or BMI.
Antioxidants for female subfertility
Showell MG, Mackenzie-Proctor R, Jordan V +1 more
Investigators compared oral antioxidants, including: combinations of antioxidants, N-acetylcysteine, melatonin, L-arginine, myo-inositol, carnitine, selenium, vitamin E, vitamin B complex, vitamin C, vitamin D+calcium, CoQ10, and omega-3-polyunsaturated fatty acids versus placebo
Vitamin D status in patients with rosacea
Ekiz O
Patients with rosacea have relatively high serum vitamin D levels compared to control groups.
Crucial Role of Vitamin D in the Musculoskeletal System
Wintermeyer E, Ihle C, Ehnert S +6 more
Study examining vitamin D's dual role in maintaining bone health and supporting muscle function, including mechanisms at the cellular level.
Prevention of benign paroxysmal positional vertigo with vitamin D supplementation: A randomized trial
Jeong SH, Kim JS, Kim HJ
Supplementation with vitamin D and calcium reduced the annual recurrence of benign paroxysmal positional vertigo in patients with low vitamin D.
Vitamin D supplementation for treatment of seasonal affective symptoms in healthcare professionals: a double-blind randomised placebo-controlled trial
Frandsen TB, Pareek M, Hansen JP +1 more
There were no significant between-group differences in the primary (SIGH-SAD) and secondary (WHO-5) as well as the exploratory outcome measures. Thus, the study failed to demonstrate an effect of vitamin D on SAD symptoms, but our findings may be limited by confounders.
Vitamin D and innate immune function: effects on monocyte and macrophage antimicrobial activity
Hewison M
1,25-dihydroxyvitamin D induces cathelicidin in macrophages and enhances antimicrobial killing capacity
Effects of vitamin D supplementation on ovulation and pregnancy in women with polycystic ovary syndrome: a systematic review and meta-analysis
Yang M, et al.
Vitamin D supplementation contribute to the higher pregnancy and ovulation rates, and lower androgen, LH, FSH and early miscarriage rates in women with PCOS. However, no significant improvement was observed in fertilization rate or cleavage rate.
Effects of Vitamin D on Endometriosis-Related Pain: A Double-Blind Clinical Trial
Almassinokiani F, Khodaverdi S, Solaymani-Dodaran M +2 more
we did not find significant differences in severity of pelvic pain (p=0.24) and dysmenorrhea (p=0.45) between the 2 groups
Randomized Trial of Vitamin D Supplementation to Prevent Seasonal Influenza and Upper Respiratory Infection in Patients With Inflammatory Bowel Disease
Vitamin D 500 IU/day did not reduce the incidence of influenza in patients with inflammatory bowel disease.
Efficacy and safety of active vitamin D supplementation in chronic spontaneous urticaria patients
Mohamed AA, Hussein MS, Salah EM +5 more
After alfacalcidol administration, the study group showed significant higher level of 25(OH) D compared to the placebo group. In addition, the mean serum level of IL6, hsCRP and TNFα significantly decreased.
The Association between Vitamin D Deficiency and Perinatal Depression: A Systematic Review and Meta-Analysis
Yuan Y, Qu L, Sun Q +1 more
Reduced vitamin D levels are significantly associated with the incidence of perinatal depression.
Correlation of low serum vitamin-D with uterine leiomyoma: a systematic review and meta-analysis
Women with uterine leiomyoma had significantly lower serum vitamin D levels than women without fibroids.
Vitamin D Supplementation for Benign Paroxysmal Positional Vertigo: A Systematic Review
Most studies reported fewer BPPV recurrences with vitamin D supplementation.
Clinical and serological association of plasma 25-hydroxyvitamin D levels in lupus and the short-term effects of oral vitamin D supplementation
Kavadichanda C, et al
High-dose oral vitamin D supplementation seems safe and more effective in improving vitamin D levels in SLE.
Long-Term Effect of Randomization to Calcium and Vitamin D Supplementation on Health in Older Women: Postintervention Follow-up of a Randomized Clinical Trial
Thomson CA, et al
Calcium and vitamin D supplements seemed to reduce cancer mortality and increase CVD mortality after more than 20 years of follow-up.
The Effects of Vitamin D and Marine Omega-3 Fatty Acid Supplementation on Chronic Knee Pain in Older US Adults: Results From a Randomized Trial
MacFarlane LA, Cook NR, Kim E +7 more
Our findings indicate that vitamin D and n-3 FA supplementation for a mean of 5.3 years does not reduce knee pain or improve function or stiffness in a large sample of US adults with chronic knee pain.
Vitamin D status and serotonin metabolism: a randomized controlled trial of supplementation
Jorde R, Sneve M, Figenschau Y +2 more
Depression scale scores improved significantly in the vitamin D groups among participants with low baseline vitamin D
Effect of high-dose vitamin D3 on hospital length of stay in critically ill patients with vitamin D deficiency: the VITdAL-ICU randomized clinical trial
Amrein K, et al.
Among critically ill patients with vitamin D deficiency, administration of high-dose vitamin D3 compared with placebo did not reduce hospital length of stay, hospital mortality, or 6-month mortality.
Is diabetic neuropathy associated with vitamin D status? A meta-analysis
Yammine K, et al.
Vitamin D deficiency has been found to be highly prevalent among diabetic patients with neuropathy. Since 25(OH)D has been implicated in glucose haemostasis and showed benefit in reducing neuropathy symptoms, its supplementation is warranted for this population of patients.
Monthly high-dose vitamin D treatment for the prevention of functional decline: a randomized clinical trial
Bischoff-Ferrari HA, Dawson-Hughes B, Orav EJ
High monthly doses were associated with a significantly higher rate of falls (66.9% vs 47.9%).
Combination therapy with saxagliptin and vitamin D for the preservation of β-cell function in adult-onset type 1 diabetes: a multi-center, randomized, controlled trial
Saxagliptin combined with vitamin D preserved beta-cell function in adult-onset type 1 diabetes.
Effect of vitamin D supplementation on hormones and menstrual cycle regularization in polycystic ovary syndrome women: A systematic review and meta-analysis
Han Y, Cao Q, Qiao X +1 more
Our study indicated that vitamin D supplementation could reduce serum LH (standard mean difference [SMD]: -0.41; 95% confidence interval [CI]: -0.54, -0.28; p < 0.01).
Relationships between Premenstrual Syndrome (PMS) and Diet Composition, Dietary Patterns and Eating Behaviors
Oboza P, Ogarek N, Wójtowicz M +1 more
Studies published so far showed that low intake of simple carbohydrates, fats, salt, and alcohol, and high of fresh, unprocessed foods rich in B vitamins, vitamin D, zinc, calcium, and omega-3 fat
Vitamin D serum levels and temporomandibular disorders: A systematic review and meta-analysis
Tabrizi R, et al.
Considering the low to very low certainty of the evidence, vitamin D serum levels are significantly lower, and vitamin D deficiency is significantly more prevalent in TMD patients.
Effects of alendronate and alfacalcidol on bone in patients with myasthenia gravis initiating glucocorticoids treatment
Lv L, et al
However, treatment with alfacalcidol alone failed to prevent bone loss in patients with MG receiving glucocorticoid therapy.
Association of Preoperative Vitamin D Deficiency With Retear Rate and Early Pain After Arthroscopic Rotator Cuff Repair: A Retrospective Cohort Study
Ryu KJ
Preoperative vitamin D deficiency was associated with a higher retear rate and early pain after arthroscopic rotator cuff repair.
Effect of Long-term Vitamin D3 Supplementation vs Placebo on Risk of Depression or Clinically Relevant Depressive Symptoms and on Change in Mood Scores: A Randomized Clinical Trial
Okereke OI, Reynolds CF, Mischoulon D
Treatment with vitamin D3 compared with placebo did not result in a statistically significant difference in the incidence and recurrence of depression or clinically relevant depressive symptoms or for change in mood scores. These findings do not support the use of vitamin D3 in adults to prevent depression.
Supplemental Vitamin D and Incident Fractures in Midlife and Older Adults
Vitamin D3 2000 IU daily did not reduce fracture risk compared with placebo in generally healthy adults.
The effect of three years of vitamin D supplementation on erectile dysfunction: Results from the randomized placebo-controlled D-Health Trial
Duarte Romero B, Waterhouse M, Baxter C +3 more
After three years of supplementation, the mean serum 25-hydroxy vitamin D concentration was 76 nmol/L... in the placebo group and 106 nmol/L... in the vitamin D group
Is Vitamin D Supplementation Effective for Low Back Pain? A Systematic Review and Meta-Analysis
Zadro JR, Shirley D, Ferreira M +4 more
Is Vitamin D Supplementation Effective for Low Back Pain? A Systematic Review and Meta-Analysis.
Interventions to prevent falls in community-dwelling older adults: US Preventive Services Task Force recommendation statement
Grossman DC, Curry SJ, Owens DK
The Task Force recommends against vitamin D supplementation to prevent falls.
Effect of vitamin D supplementation on testosterone levels in men: a randomized controlled trial
Pilz S, Frisch S, Koertke H +3 more
Total and free testosterone increased significantly in the vitamin D group while placebo showed no change
The Benefits of Add-on Therapy of Vitamin D 5000 IU to the Vitamin D Levels and Symptoms in Diabetic Neuropathy Patients: A Randomized Clinical Trial
Pinzon RT, Wijaya VO, Veronica V
The addition of oral vitamin D 5000 IU to standard treatment significantly improves pain, mood, and vitamin D levels more effectively than standard treatment alone in patients with diabetic neuropathy.
Low Vitamin D Serum Levels in a Cohort of Myasthenia Gravis Patients in Argentina
Justo ME, et al
Patients are more likely to have nonsufficient levels of vitD compared to healthy people and patients with more severe disease have lower levels of vitD.
Role of VDR gene polymorphisms and environmental factors in the development of skin cancers: evidence by updated meta-analysis
Tizaoui K, Chikhaoui A, Yacoub-Youssef H
Meta-analysis showed that the VDR Fok I polymorphism was associated with melanoma risk (CT vs. CC + TT, P = 0.020), with CT genotype as a significant risk factor.
Oral vitamin D supplementation for adults with obesity undergoing bariatric surgery
Vitamin D supplementation improved vitamin D status but evidence for weight and clinical outcomes remained very uncertain.
Magnesium status and supplementation influence vitamin D status and metabolism: results from a randomized trial
Dai Q, et al.
Our findings suggest that optimal magnesium status may be important for optimizing 25(OH)D status.
Vitamin D supplementation to prevent acute respiratory infections: individual participant data meta-analysis
Vitamin D supplementation reduced acute respiratory infection risk, with greatest benefit at baseline 25(OH)D below 25 nmol/L.
The effect of vitamin D supplementation on depressive symptoms in adults: A systematic review and meta-analysis of randomized controlled trials
Mikola T, Marx W, Lane MM
Vitamin D supplementation >= 2,000 IU/day appears to reduce depressive symptoms. Future research should investigate possible benefits of augmenting standard treatments with vitamin D in clinical depression.
High dose vitamin D supplementation can improve menstrual problems, dysmenorrhea, and premenstrual syndrome in adolescents
Bahrami A, et al.
High dose vitamin D supplementation can reduce the prevalence of PMS and dysmenorrhea as well as has positive effects on the physical and psychological symptoms of PMS.
Vitamin D and hematopoietic and mesenchymal stem cell function: a review of clinical evidence
Cortes M, Chen MJ, Stachura DL +7 more
Vitamin D signalling amplified haematopoietic stem and progenitor cell production
Effect of 25-hydroxyvitamin D levels on the internalising dimension as a transdiagnostic risk factor: Mendelian randomisation study
Konzok J, et al.
Following current transdiagnostic approaches to investigate mental disorders, our results focused on the shared genetic basis between different internalising phenotypes and provide no evidence for an effect of 25OHD on the internalising dimension.
Vitamin D and Graves' Disease: A Meta-Analysis Update
Xu MY, Cao B, Yin J +3 more
The association between vitamin D levels and Graves' disease is not well studied. This update review aims to further analyze the relationship in order to provide an actual view of estimating the risk.
Vitamin D status and oxytocin: mechanistic and clinical evidence review
Patrick RP, Ames BN
Vitamin D response elements were identified in the oxytocin gene promoter
Improvement in Neuropathy Specific Quality of Life in Patients with Diabetes after Vitamin D Supplementation
Alam U, Fawwad A, Shaheen F +1 more
Vitamin D is effective in improving quality of life in patients with painful diabetic neuropathy.
Impact of Vitamin D Supplementation on Cognition in Adults With Mild to Moderate Vitamin D Deficiency: Outcomes From the VitaMIND Randomized Controlled Trial
Corbett A, et al.
Vitamin D supplementation produced no measurable improvement in cognitive outcomes in older adults with mild to moderate vitamin D deficiency.
Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis
Vitamin D3 raised serum 25-hydroxyvitamin D more effectively than vitamin D2.
Vitamin D and T-cell activation: 25-hydroxyvitamin D is required for human T-cell antigen receptor signalling
von Essen MR, Kongsbak M, Schjerling P +3 more
Naive T cells failed to activate without vitamin D, which was required to induce antigen receptor signalling
Effect of vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial
Nowak A, Boesch L, Andres E
Vitamin D treatment significantly improved fatigue in otherwise healthy persons with vitamin D deficiency.
Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies
Abboud M
VDS is promising in improving sleep quality; however, its effect on sleep quantity and disorders needs to be further investigated.
Association between serum vitamin D level and Graves' disease: a systematic review and meta-analysis
Pang B, Li L, Liu X +4 more
This meta-analysis aims to analyze the relationship between serum vitamin D and Graves' disease.
Vitamin D levels in children and adolescents with obsessive compulsive disorder
Yazici KU, et al.
The vitamin D levels of newly diagnosed OCD cases were lower but not statistically different than healthy controls. Furthermore, the study does also not support the presence of a significant association between serum vitamin D levels and OCD.
Vitamin D supplementation and telomerase activity: a randomized controlled trial
Zhu H, Guo D, Li K +6 more
Telomerase activity increased significantly by 19.2% in the vitamin D group with no change on placebo
Annual high-dose vitamin D3 and mental well-being: randomised controlled trial
Sanders KM, Stuart AL, Williamson EJ
The lack of improvement in indices of mental well-being in the vitamin D group does not support the hypothesis that an annual high dose of vitamin D3 is a practical intervention to prevent depressive symptoms in older community-dwelling women.
Comparison of the Effect of Daily Vitamin D2 and Vitamin D3 Supplementation on Serum 25-Hydroxyvitamin D Concentration and Importance of Body Mass Index: A Systematic Review and Meta-Analysis
Daily vitamin D3 increased total 25(OH)D more than D2, with attenuated response at higher body mass index.
Vitamin D supplementation and cancer incidence and mortality: VITAL randomized controlled trial
Manson JE, Cook NR, Lee IM +13 more
Vitamin D did not lower invasive cancer incidence over a median 5.3 years
Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis
Vitamin D supplementation had no clinically meaningful effect on bone mineral density at most sites.
Effects of High Dose Bolus Cholecalciferol on Free Vitamin D Metabolites, Bone Turnover Markers and Physical Function
High-dose bolus cholecalciferol raised vitamin D metabolites without improving bone turnover or physical function.
Vitamin D deficiency in alopecia areata: a systematic review and meta-analysis
Lee S, Kim BJ, Lee CH +1 more
Alopecia areata patients had significantly lower serum vitamin D levels and higher odds of deficiency than controls.
Vitamin D in ankylosing spondylitis: review and meta-analysis
Cai G, Wang L, Fan D +10 more
Lower serum vitamin D in ankylosing spondylitis was inversely associated with BASDAI disease activity.
Safety Information
Potential Side Effects
At normal doses vitamin D is very well tolerated. Toxicity is a hypercalcaemia syndrome — nausea, excessive thirst and urination, confusion, kidney stones — and essentially only occurs with sustained intakes far above 4000 IU daily, or from dosing errors in liquid concentrates. Two large trials of annual or monthly mega-doses reported more falls and fractures, not fewer, which is the main argument against bolus regimens.
Contraindications
Contraindicated in hypercalcaemia and in granulomatous conditions such as sarcoidosis and tuberculosis, where unregulated extrarenal conversion to calcitriol can drive calcium levels dangerously high. Use caution with primary hyperparathyroidism, significant renal impairment, and a history of calcium kidney stones.
Drug Interactions
- Thiazide diuretics — combined with vitamin D and calcium, can raise the risk of hypercalcaemia.
- Corticosteroids — reduce calcium absorption and impair vitamin D metabolism with long-term use.
- Orlistat and bile acid sequestrants — reduce absorption of fat-soluble vitamins; separate doses.
- Anticonvulsants (phenytoin, carbamazepine, phenobarbital) — accelerate breakdown of vitamin D; higher doses often needed.
- Digoxin — hypercalcaemia from excess vitamin D increases the risk of digoxin toxicity.
Pregnancy & Breastfeeding
Pregnancy: safe
Breastfeeding: safe
Dosage Guidelines
Dosage Used in Studies
1000-4000 IU
Best Time to Take
With a meal containing fat
Best Form
Softgel or liquid D3 (cholecalciferol)
Bioavailability
Fat-soluble vitamin best absorbed with dietary fat. D3 (cholecalciferol) more effective than D2 (ergocalciferol) at raising blood levels.
Dosing by Goal
| Goal | Dose | Notes |
|---|---|---|
| General maintenance (adults) | 800-2000 IU (20-50 mcg) daily | Enough to keep most adults above 50 nmol/L. Take with the largest fat-containing meal of the day. |
| Correcting documented deficiency | 50,000 IU weekly for 6-8 weeks, then maintenance | Standard repletion protocol. Retest 25(OH)D roughly three months after starting, not sooner. |
| Higher body weight or obesity | 2-3x the standard dose | Vitamin D distributes into adipose tissue, so the same dose produces a lower serum level. |
| Older adults, fracture risk | 800 IU daily with 1000-1200 mg calcium | The combination, not vitamin D alone, is what reduced fractures in trials of institutionalised older adults. |
| Upper limit | 4000 IU (100 mcg) daily | The tolerable upper intake level for adults. Sustained intake well above this risks hypercalcaemia. |
Forms Compared
D3 (cholecalciferol)
Best for Almost everyone
The default. Raises and sustains serum 25(OH)D more effectively than D2. Usually derived from lanolin.
D2 (ergocalciferol)
Best for Vegans, high-dose prescriptions
Plant or fungal source. Works, but has a shorter half-life and raises 25(OH)D less per unit than D3.
Vegan D3 (lichen-derived)
Best for Vegans who want D3
Chemically identical to lanolin D3. Costs more; no functional difference.
D3 + K2 combinations
Best for People also taking calcium
The theoretical rationale is directing calcium to bone rather than arteries. Plausible, not proven by hard outcome trials.
Oil-based drops or softgels
Best for Low-fat diets, malabsorption
Absorption depends on dietary fat, so an oil carrier is more reliable than a dry tablet taken without food.
Food & Timing
Take with a meal containing fat — absorption is substantially higher than on an empty stomach. Time of day does not matter; consistency does. Daily dosing outperforms weekly or monthly bolus dosing in infection and falls trials.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.