Condition
    Effectiveness 2/5

    Vitamin D for Endometriosis

    Low vitamin D status is associated with endometriosis severity, and small trials suggest supplementation reduces pelvic pain, but lesion outcomes are untested.

    Overview

    Low vitamin D status is associated with endometriosis severity, and small trials suggest supplementation reduces pelvic pain, but lesion outcomes are untested.

    Verdict

    Mixed evidence

    Low vitamin D status is associated with endometriosis severity, and small trials report reduced pelvic pain with supplementation — but lesion outcomes are untested.

    How It Works

    Vitamin D receptors are expressed in endometrial tissue and immune cells; vitamin D modulates local inflammation, angiogenesis and the immune dysregulation that permits ectopic implant survival.

    Dosing & Protocol

    Typical dose

    Recommended dose
    Test first; correct deficiency per standard guidance (commonly 1000-2000 IU daily maintenance)
    Expected timeframe
    3 months for pain-signal assessment

    Protocol

    notes
    Take with a fat-containing meal
    dosage
    Test 25-OH vitamin D first; correct deficiency per standard guidance, commonly 1000-2000 IU daily maintenance
    duration
    3 months, then recheck levels and reassess

    Evidence

    What the studies say

    Observational studies consistently link lower vitamin D levels with endometriosis presence and severity, though reverse causation is possible. Two small randomised trials of vitamin D supplementation reported reduced pelvic pain scores, but results have been inconsistent and no trial has measured lesion size or fertility outcomes. Correcting documented deficiency is sensible for bone and general health regardless; expecting it to treat the disease goes beyond the evidence.

    Effects of Vitamin D on Endometriosis-Related Pain: A Double-Blind Clinical Trial

    Score: 7/10
    2016
    rct
    n=39

    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

    View source

    Antioxidant vitamins supplementation reduce endometriosis related pelvic pain in humans: a systematic review and meta-analysis

    Score: 9/10
    2023
    meta_analysis
    n=589

    Zheng SH, Chen XX, Chen Y +3 more

    antioxidant vitamins supplementation reduce endometriosis related pelvic pain in humans

    View source

    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

    Score: 8/10
    2020
    rct
    n=69

    Nodler JL, DiVasta AD, Vitonis AF +3 more

    Participants in the vitamin D arm experienced significant improvement in VAS pain

    View source

    The effect of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis

    Score: 7/10
    2021
    rct
    n=60

    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)

    View source

    Effect of Dietary Interventions on Endometriosis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    Score: 9/10
    2024
    meta_analysis
    n=716

    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]

    View source

    Safety

    Caveats

    {"Association with severity may reflect reverse causation","No evidence it shrinks lesions or improves fertility","Pain trials are small and inconsistent"}

    Less likely to help if

    Women with normal vitamin D levels have no trial basis to expect benefit from higher doses, and megadosing carries hypercalcaemia risk.

    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.