rct
    2026
    High Quality

    Vitamin D in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After COVID-19 or Vaccination: A Randomized Controlled Trial

    Kodama T, et al

    Published in Nutrients

    Methodology

    Randomised controlled trial of guided vitamin D replacement therapy versus control over 12 weeks in adults with post-COVID/post-vaccination ME/CFS and baseline 25(OH)D insufficiency or deficiency; validated fatigue and symptom scales.

    Key Findings

    In 91 patients with ME/CFS following COVID-19 infection or vaccination who had vitamin D insufficiency or deficiency, guided vitamin D replacement over 12 weeks produced significantly greater reduction in fatigue and ME/CFS symptom scores than control, with improvement tracking the rise in serum 25(OH)D.

    Conclusions

    Vitamin D replacement therapy guidance significantly reduced ME/CFS symptoms in patients with vitamin D insufficiency or deficiency.

    Limitations

    Modest sample size; single-country population; open guidance rather than fully blinded dosing; short 12-week horizon with no follow-up after cessation; benefit may be confined to those starting deficient.

    Supplements Studied

    Vitamin D
    Vitamin

    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.

    Related Health Concerns

    Study Details

    Year:2026
    Sample Size:91
    Duration:12 weeks
    Quality Score:7/10

    Disclosures

    Funding

    Academic/institutional research funding

    This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.