Multiple Sclerosis News TodayTaking High-Dose Vitamin D Daily Over the Long Term Helps Reduce MS Relapses

🎯 Guideline Refinement / Applied Specificity

A network meta-analysis of 32 RCTs (2,254 MS patients) found high-dose vitamin D (>4,000 IU/day) added to standard disease-modifying therapy for more than one year cut relapse risk 20% and reduced active inflammatory lesions 49% versus placebo.

Clinical Considerations

• Benefit required long-term use: supplementation under one year showed no significant effect on relapse risk or disability.
• High-dose, long-duration regimens showed the greatest benefit for relapse risk and disability scores; mid-dose, long-duration performed best specifically for relapse rates.
• No increase in serious adverse events (death, hospitalization, kidney stones) was observed across dosing groups.
• GRADE certainty was rated very low for the specific dosing comparisons, moderate for long-term relapse/disability outcomes overall.

Practice Applications

• Consider high-dose, long-term vitamin D as adjuvant therapy in patients already on disease-modifying treatment.
• Recognize short-term supplementation (under one year) is unlikely to show measurable benefit.
• Monitor patients for expected safety profile rather than anticipating new adverse event signals.
• Interpret specific dosing thresholds cautiously given very-low-certainty evidence on dose comparisons.