Safety and T Cell Modulating Effects of High Dose Vitamin D.sub.3 Supplementation in Multiple Sclerosis

A poor vitamin D status has been associated with a high disease activity of multiple sclerosis (MS). Recently, we described associations between vitamin D status and peripheral T cell characteristics in relapsing remitting MS (RRMS) patients. In the present study, we studied the effects of high dose vitamin D.sub.3 supplementation on safety and T cell related outcome measures. Fifteen RRMS patients were supplemented with 20 000 IU/d vitamin D.sub.3 for 12 weeks. Vitamin D and calcium metabolism were carefully monitored, and T cell characteristics were studied by flowcytometry. All patients finished the protocol without side-effects, hypercalcaemia, or hypercalciuria. The median vitamin D status increased from 50 nmol/L (31-175) at week 0 to 380 nmol/L (151-535) at week 12 (P