COVID vaccination caused ME-CFS symptoms, cured by Vitamin D in most people
Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination
Nutrition Volume 134, June 2025 https://doi.org/10.1016/j.nut.2025.112718
Background Prolonged symptoms have been reported following both COVID-19 infection and vaccination, with some cases leading to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Of 80 patients presenting to our hospital with postvaccination syndrome, 28 met the diagnostic criteria for ME/CFS. We conducted a retrospective study on these 28 patients.
Methods We measured serum 25-hydroxyvitamin D levels in 28 patients who developed ME/CFS after COVID-19 vaccination between August 2022 and February 2024. Vitamin D replacement therapy included dietary counseling, sun exposure recommendations, and oral vitamin D supplementation. We evaluated changes in blood vitamin D levels and symptom improvement.
Results At initial visit, 27 of 28 patients diagnosed with ME/CFS had insufficient or deficient serum 25-hydroxyvitamin D levels (16 ± 4 ng/mL, mean ± SD). Following vitamin D replacement therapy, we observed an increase in blood vitamin D levels (28 ± 5 ng/mL) associated with a decrease in ME/CFS diagnostic symptoms (from 10.3 ± 2.1 to 3.3 ± 2.0). Notably, 23 of 28 patients (82%) no longer met ME/CFS diagnostic criteria after the therapy. Among the symptoms, sleep problems showed the most improvement (71%), followed by autonomic symptoms (68%).
Conclusions For patients developing ME/CFS after COVID-19 vaccination with insufficient or deficient vitamin D levels, appropriate vitamin D replacement therapy under medical guidance may lead to symptomatic relief. We are preparing a randomized controlled trial to evaluate the efficacy of vitamin D replacement therapy in individuals with ME/CFS who have developed vitamin D deficiency following COVID-19 infection or vaccination.
More than 1,000 IU of Vitamin D would have been far better

Making an RCT to prove that Vitamin D helps ME/CFS due to both COVID infection and vaccination
Letter to Editor: Perhaps there is no ME/CFS resulting from COVID Vaccination
Post-Vaccination Syndromes: The Evidence and a Roadmap for Rigorous Research
30 December 2025 https://doi.org/10.1002/rmv.70100 Behind Paywall
Review of the above item on TrialSite News Dec 2025
Perhaps 40% more likely to have CFS/ME if had COVID Infection - July 2025
Elevated risk of new-onset chronic fatigue syndrome/myalgic encephalomyelitis up to four years after SARS-CoV-2 infection - July 2025 PDF

More ME/CFS if COVID infection - Sept 2024
Impact of COVID-19 on myalgic encephalomyelitis/chronic fatigue syndrome-like illness prevalence: A cross-sectional survey
PLOS 1 Sept. 2024 https://doi.org/10.1371/journal.pone.0309810 PDF

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