Safety and Immunologic Effect of Low Dose Versus High Dose Vitamin D3 in Multiple Sclerosis

Inclusion Criteria: * Between ages of 18-55 years (inclusive) * Serum 25(OH) vitamin D levels between 20-50 ng/mL and a candidate for vitamin D supplementation * Patients with or without immunomodulatory therapy for RRMS * Diagnosis of multiple sclerosis Exclusion Criteria: * Serum 25(OH) vitamin D deficient level \< 20 ng/mL * High dose vitamin D supplementation in the past 3 months * Pregnancy * History of tuberculosis, hyperparathyroidism, sarcoidosis or kidney stones * Baseline serum creatinine above 1.5 * Hypersensitivity to vitamin D preparations * Milk allergy * Unable to consent