D-Lay Trial: High-Dose Vitamin D Retards Multiple Sclerosis Save

Vitamin D plays an important role in immune function and in the VITAL study was shown to reduce the risk of autoimmune disease. Also a deficiency of vitamin D, can be a risk factor for multiple sclerosis (MS). This study assessed whether high-dose cholecalciferol monotherapy in may influence signs of developing MS.

The D-Lay MS trial was a parallel, double-blind, randomized placebo-controlled clinical trial in France. Recruited adults (aged 18 to 55 years) with untreated clinically isolated syndrome (CIS) (typical for multiple sclerosis (MS) for less than 90 days, serum vitamin D concentration less than 100 nmol/L, and diagnostic magnetic resonance imaging (MRI) meeting 2010 criteria for dissemination in space or 2 or more lesions and presence of oligoclonal bands were included.

Patients were randomized 1:1 to receive oral cholecalciferol 100 000 IU (n = 163) or placebo (n = 153) every 2 weeks for 24 months.  The primary outcome measure was disease activity, defined as occurrence of a relapse and/or MRI activity (new and/or contrast-enhancing lesions) over 24 months of follow-up, also analyzed as separate secondary outcomes.

The primary analysis included 303 patients (median age 34 years; 70% women), 91% of whom completed the 24-month trial. Evidence of disease activity was less with vitamin D (60.3%) compared to placebo (74.1%; HR 0.66 [95% CI, 0.50-0.87]; P = .004). 

Other secondary measures also favored vitamin D treatment:

• Median time to disease activity (vitamin D 432 days vs PBO 224 days; log-rank P = .003)
• MRI outcomes favored Vit D - (MRI activity (57.1% vs 65.3%; HR, 0.71) [95% CI, 0.53-0.95]; P = .02)
  • New lesions (46.2% vs 59.2%; HR, 0.61 [95% CI, 0.44-0.84]; P = .003)
• No differences were seen or relapse (17.9% vs 21.8%) 
• Severe adverse events (17 vs 13 in the placebo group)

Oral cholecalciferol 100 000 IU every 2 weeks significantly reduced disease activity in CIS and early relapsing-remitting MS.