Outcome
    Limited

    Vitamin D for Hair Growth

    Correcting vitamin D deficiency supports hair cycling; deficiency is associated with alopecia, but extra D beyond sufficiency has no growth benefit.

    Overview

    Correcting vitamin D deficiency supports hair cycling; deficiency is associated with alopecia, but extra D beyond sufficiency has no growth benefit.

    Verdict

    Mixed evidence

    How It Works

    Vitamin D receptors in follicles regulate anagen initiation; deficiency is associated with telogen effluvium and alopecia areata in observational data.

    Dosing & Protocol

    Typical dose

    Recommended dose
    1,000–2,000 IU/day to reach 30–50 ng/mL.
    Expected timeframe
    3-6 months

    Protocol

    form
    Vitamin D3 (cholecalciferol); topical vitamin D analogues such as calcipotriol have been trialled in alopecia areata separately
    duration
    3-6 months, matching the hair cycle
    co factor
    Take with a fat-containing meal. Evidence is mixed. The vitamin D receptor has a documented role in the hair follicle cycle - loss-of-function mutations cause hereditary vitamin D-resistant rickets with total alopecia, and VDR-knockout mice lose hair, which establishes that the receptor matters for follicle cycling. Observational studies consistently find lower 25(OH)D in people with telogen effluvium, female pattern hair loss and alopecia areata. What is missing is intervention evidence: randomised trials of vitamin D supplementation for hair growth are few, small and inconsistent.
    titration
    Up to 4,000 IU/day, which is the tolerable upper intake level for adults
    starting dose
    1,000-2,000 IU/day of vitamin D3 with a meal containing fat

    Evidence

    What the studies say

    Meta-analyses show lower vitamin D levels in alopecia populations versus controls. Interventional evidence is limited to deficiency-correction contexts; no trials show benefit at replete levels.

    The Role of Vitamins and Minerals in Hair Loss: A Review

    Score: 6/10
    2019
    systematic_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.

    View source

    Safety

    Caveats

    Test first; repletion is the goal, not megadosing. Pair with magnesium and dietary fat for absorption.

    Less likely to help if

    Deficiency-corrected individuals seeking additional benefit.

    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.