Kodama, Shinichiro, Konishi, Nafuko, Hirai, Yuriko et al. · Nutrition (Burbank, Los Angeles County, Calif.) · 2025 · DOI
This study looked at 28 patients who developed ME/CFS after COVID-19 vaccination and found that most had very low vitamin D levels. When these patients received vitamin D treatment through diet, sun exposure, and supplements, their vitamin D levels improved and their ME/CFS symptoms significantly decreased—with 82% of patients no longer meeting ME/CFS criteria after treatment. Sleep problems and autonomic symptoms (like heart rate and blood pressure changes) showed the most improvement.
This is one of the first studies systematically examining vitamin D status in post-vaccination ME/CFS and showing potential symptomatic benefit from replacement therapy. The finding that 82% of patients experienced remission from ME/CFS criteria following vitamin D treatment offers hope for a potentially modifiable factor in a subset of post-vaccination ME/CFS cases and may inform future mechanistic investigations and clinical trials.
This study does not prove that vitamin D deficiency causes ME/CFS, only that correction of deficiency was associated with symptom improvement in this specific group. The lack of a control group, randomization, or blinding means we cannot exclude placebo effects, natural recovery, or confounding factors. Results apply only to ME/CFS patients with documented vitamin D deficiency; generalizability to all ME/CFS populations is unknown.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Kodama, Shinichiro, Konishi, Nafuko, Hirai, Yuriko, Fujisawa, Akinori, Nakata, Mitsuko, Teramukai, Satoshi, et al. (2025). Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination.. Nutrition (Burbank, Los Angeles County, Calif.). https://doi.org/10.1016/j.nut.2025.112718
BibTeX
@article{mecfsatlas-kodama-2025-efficacy-vitamin,
author = {Kodama, Shinichiro and Konishi, Nafuko and Hirai, Yuriko and Fujisawa, Akinori and Nakata, Mitsuko and Teramukai, Satoshi and Fukushima, Masanori},
title = {Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination.},
journal = {Nutrition (Burbank, Los Angeles County, Calif.)},
year = {2025},
doi = {10.1016/j.nut.2025.112718},
note = {PubMed: 40090177},
url = {https://www.mecfsatlas.com/evidence/kodama-2025-efficacy-vitamin},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-25. https://www.mecfsatlas.com/evidence/kodama-2025-efficacy-vitamin
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