Results from a small study just published has demonstrated taking 10,000 IU of vitamin D appears to be safe for people with MS and could reduce the proportion of the immune cells that are thought to drive MS activity.

The study included 40 people with relapsing remitting MS in the USA. Each participant received either 800 IU or 10,400 IU of vitamin D3 (cholecalciferol) every day for six months. Blood tests were performed before the study started, after 3 months and 6 months. The researchers found that for the participants taking the higher dose, levels of vitamin D in the blood increased and proportion of specific immune system T-cells which are related to MS activity decreased. The higher the levels of vitamin D in the blood, the greater the reduction in the numbers of these cells.

During the study there were a few adverse events but they were all minor and the numbers did not differ between the groups.

These results are encouraging as it shows that vitamin D may be effective against immune system activity that is associated with MS. However the study was only a pilot study in a small number of people and the numbers of people involved were too small to detect differences in MS disease activity.

The researchers are now recruiting 172 people with relapsing remitting MS across the USA for a larger trial of vitamin D supplementation, to compare the effectiveness of 600 IU of vitamin D supplementation versus 5000 IU vitamin D supplementation at reducing MS disease activity, when added to standard therapy with Copaxone (glatiramer acetate).