Outcome
    Limited

    Zinc for Reproductive Health

    Zinc is essential for spermatogenesis and correcting deficiency improves semen parameters, but supplementation in replete men does not improve fertility outcomes.

    Overview

    Zinc is essential for spermatogenesis and correcting deficiency improves semen parameters, but supplementation in replete men does not improve fertility outcomes.

    Verdict

    Mixed evidence

    How It Works

    Zinc stabilises sperm chromatin, protects membranes from oxidative damage and is required for testosterone synthesis in Leydig cells.

    Dosing & Protocol

    Typical dose

    Recommended dose
    8-11 mg/day meets requirements; fertility trials used 25-66 mg/day of elemental zinc with mixed results
    Expected timeframe
    3-6 months

    Protocol

    form
    Zinc gluconate, sulfate or picolinate with food
    duration
    3-6 months, matching the roughly 74-day cycle of sperm production
    co factor
    Take with food, separated from iron and from tetracycline or quinolone antibiotics by two hours. Evidence is mixed. Zinc is highly concentrated in the prostate and seminal fluid, is required for spermatogenesis, sperm membrane stability and acrosome function, and severe deficiency causes hypogonadism and impaired fertility that corrects on repletion. Trial results in unselected men are inconsistent: the large FAZST trial randomised 2,370 couples to zinc 30 mg plus folic acid 5 mg and found no improvement in live birth rate or semen quality, which substantially weakened earlier positive findings.
    titration
    Do not exceed the tolerable upper intake level of 40 mg/day without medical supervision; trial doses above this were time-limited and supervised
    starting dose
    11 mg/day for men meets requirements; male fertility trials used 25-66 mg/day of elemental zinc, often with 5 mg/day of folic acid

    Evidence

    What the studies say

    The FAZST randomised trial of zinc plus folic acid in over 2,300 couples found no improvement in live birth rates or semen quality. Benefit is confined to documented deficiency, where parameter improvements are consistent.

    Effect of Folic Acid and Zinc Supplementation in Men on Semen Quality and Live Birth Among Couples Undergoing Infertility Treatment: A Randomized Clinical Trial

    Score: 10/10
    2020
    rct
    n=2370

    Schisterman EF, Sjaarda LA, Clemons T +4 more

    Folic acid and zinc supplementation in men did not significantly improve semen quality or live birth.

    View source

    Zinc levels in seminal plasma and their correlation with male infertility: A systematic review and meta-analysis

    Score: 7/10
    2016
    meta_analysis
    n=3467

    Zhao J, Dong X, Hu X +7 more

    Zinc supplementation was found to significantly increase the semen volume, sperm motility and the percentage of normal sperm morphology.

    View source

    The Impact of Minerals on Female Fertility: A Systematic Review

    Score: 6/10
    2024
    systematic_review

    Kapper C, Stelzl P, Oppelt P +1 more

    The analysis revealed that minerals like selenium, zinc, and copp

    View source

    Safety

    Caveats

    The definitive randomised trial (FAZST) was null for both semen quality and live birth; supportive data are observational or from small unblinded supplementation studies.

    Less likely to help if

    Men with adequate zinc status, and couples whose infertility has another identified cause.

    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.