D-Lay MS
Trial question
What is the effect of high-dose cholecalciferol monotherapy in patients with clinically isolated syndrome typical for multiple sclerosis?
Study design
Multi-center
Double blinded
RCT
Population
Characteristics of study participants
70.0% female
30.0% male
N = 303
303 patients (211 female, 92 male).
Inclusion criteria: patients, aged 18-55 years, with clinically isolated syndrome typical for multiple sclerosis.
Key exclusion criteria: receipt of disease-modifying therapy; serum vitamin D levels > 100 nmol/L; history of hypercalcemia, sarcoidosis, or tuberculosis.
Interventions
N=156 vitamin D (oral cholecalciferol 100,000 IU every 2 weeks for 24 months).
N=147 placebo (oral placebo every 2 weeks for 24 months).
Primary outcome
Rate of disease activity over 24 months
60.3%
74.1%
74.1 %
55.6 %
37.0 %
18.5 %
0.0 %
Vitamin
D
Placebo
Significant
decrease ▼
NNT = 7
Significant decrease in the rate of disease activity over 24 months (60.3% vs. 74.1%; HR 0.66, 95% CI 0.5 to 0.87).
Secondary outcomes
No significant difference in relapse (17.9% vs. 21.8%; HR 0.69, 95% CI 0.42 to 1.16).
Significant decrease in new or enlarging lesions (46.2% vs. 59.2%; HR 0.61, 95% CI 0.44 to 0.84).
Significant decrease in MRI activity (57.1% vs. 65.3%; HR 0.71, 95% CI 0.53 to 0.95).
Safety outcomes
No significant difference in severe adverse events.
Conclusion
In patients, aged 18-55 years, with clinically isolated syndrome typical for multiple sclerosis, vitamin D was superior to placebo with respect to the rate of disease activity over 24 months.
Reference
Eric Thouvenot, David Laplaud, Christine Lebrun-Frenay et al. High-Dose Vitamin D in Clinically Isolated Syndrome Typical of Multiple Sclerosis: The D-Lay MS Randomized Clinical Trial. JAMA. 2025 Apr 22;333(16):1413-1422.
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