JAMA

High-dose vitamin D delays progression to multiple sclerosis

March 12, 2025

High-dose vitamin D supplementation was more effective than placebo in reducing disease activity in early multiple sclerosis (MS) and clinically isolated syndrome (CIS), suggesting that vitamin D therapy may alter the disease course and improving long-term outcomes.

Study details: The D-Lay MS randomized trial investigated the effects of high-dose oral cholecalciferol (vitamin D) on disease activity in 303 patients with CIS typical of MS. Participants received either high-dose vitamin D or placebo. The primary outcome was disease activity measured by relapses and/or MRI-detected new or contrast-enhancing lesions over 24 months.

Results: During 24 months of follow-up, disease activity was observed in 60.3% of patients in the vitamin D group vs. 74.1% in the placebo group (hazard ratio, 0.66). Median time to disease activity was longer in the vitamin D group (432 vs. 224 days). The vitamin D group also had better outcomes in all three secondary MRI measures: MRI activity (HR 0.71; P=0.02), new lesions (HR 0.61; P=0.003), and contrast-enhancing lesions (HR 0.47; P=0.001).

Source:

Thouvenot E, et al; D-Lay MS Investigators. (2025, March 10). JAMA. High-Dose Vitamin D in Clinically Isolated Syndrome Typical of Multiple Sclerosis: The D-Lay MS Randomized Clinical Trial. https://pubmed.ncbi.nlm.nih.gov/40063041/