Blaney, Greg P, Albert, Paul J, Proal, Amy D · Annals of the New York Academy of Sciences · 2009 · DOI
This study measured two types of vitamin D in the blood of patients with autoimmune and chronic diseases, including ME/CFS. The researchers found that a specific form of vitamin D (1,25-D) at high levels was associated with these conditions, but the commonly-tested form of vitamin D (25-D) was not. This suggests doctors may need to test for the right type of vitamin D to properly assess autoimmune disease.
For ME/CFS patients and researchers, this study challenges the widespread assumption that low vitamin D is causally related to ME/CFS and suggests that abnormal vitamin D metabolism (specifically elevated active vitamin D) may be more relevant. Understanding which vitamin D marker is abnormal could inform future diagnostic and therapeutic approaches targeting immune dysregulation in ME/CFS.
This study does not prove that high 1,25-D causes ME/CFS or that correcting it will treat the disease—it only demonstrates association in a cross-sectional design. It does not establish whether elevated 1,25-D is a primary driver of autoimmune dysfunction or a secondary consequence of disease, nor does it evaluate whether 1,25-D testing would improve patient outcomes. The small sample size and lack of detailed controls limit generalizability.
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 →
Spotted an error in this entry? Report it →