Vitamin D for 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.
Overview
Verdict
How It Works
Dosing & Protocol
Typical dose
- Recommended dose
- 2000-5000 IU daily (target 40-60 ng/mL)
- Expected timeframe
- 3-6 months
Protocol
- form
- Vitamin D3 (cholecalciferol)
- duration
- 3-6 months with thyroid function and antibodies
- co factor
- Take with the largest meal, and separate from levothyroxine, which must be taken on an empty stomach. Evidence is mixed and category-wide: deficiency is more common in autoimmune thyroid disease, and small trials show falling thyroid antibody titres after repletion, but no trial demonstrates improved thyroid function, reduced levothyroxine requirement, or any effect on nodules, goitre or thyroid cancer.
- titration
- Target 75-125 nmol/L, rechecking at 3 months
- starting dose
- 1000-2000 IU (25-50 mcg) vitamin D3 daily with a fat-containing meal, after checking 25-hydroxyvitamin D
Evidence
What the studies say
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.
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).
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.
Safety
Caveats
Never adjust thyroid medication yourself - untreated hypothyroidism has cardiac consequences and, in pregnancy, affects fetal brain development, so levels must be checked early and frequently in pregnancy. A thyroid lump, hoarseness, difficulty swallowing or a rapidly enlarging goitre needs urgent assessment. Safety ceiling: the tolerable upper intake level is 4000 IU (100 mcg) per day; excess causes hypercalcaemia, kidney stones and kidney injury. Avoid unsupervised use in sarcoidosis, granulomatous disease and primary hyperparathyroidism - the last matters here because parathyroid and thyroid disease are often investigated together. Interacts with thiazide diuretics and digoxin. Take levothyroxine 30-60 minutes before food, and separate it from calcium and iron by four hours. Safe in pregnancy at 400-1000 IU/day.
Less likely to help if
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.