Effects of High-Dose Vitamin D in PwMS

Research Summary: Safety and immunologic effects of high- and low-dose cholecalciferol in MS

The background

There is growing evidence to implicate a potential role for Vitamin D in the development and progression of multiple sclerosis.  For example, it has been shown that the risk of getting MS increases as you move outwards from the equator.  This phenomenon has been suggested to be linked to levels of sunlight, which correlates with Vitamin D levels.  Similarly, extensive studies have shown that people with MS with lower Vitamin D levels experience increased disability.  Furthermore, studies in mice have shown that Vitamin D can prevent or improve the course of the animal model of MS, experimental autoimmune encephalomyelitis (EAE).

For this reason, it is of interest to see whether Vitamin D could be a potential treatment for people with MS.

The study

This study was conducted by researchers at Johns Hopkins University, Duke University and Stanford University.  Forty people with relapsing-remitting MS (RRMS) were randomly assigned to either a low-dose (800IU) or high-dose (10,400IU) Vitamin D3 (cholecalciferol) group.  The groups were assessed before the study to ensure that they were well-matched in terms of gender, treatments and baseline Vitamin D levels.

All people on the trial took the Vitamin D dose daily for 6 months.  Blood samples were taken at the beginning, middle and end of the study and these were used to determine the effect of supplementation on circulating Vitamin D levels and the immune system.

The findings

This trial examined the effects of low and high-dose Vitamin D3 treatment on both the levels of Vitamin D and the immune system.  The results showed that:

• Levels of Vitamin D were increased in the blood of both groups across the 6 months of treatment.  However, the increase in the high-dose group was significantly larger than that of the low-dose group.

• The levels of interleukin-17 producing CD4+ T cells were significantly decreased in the high-dose group.  This type of T cell has been shown to play a role in the disease process in MS.  The levels were not significantly altered in the low-dose group.

• The levels of other important types of T cells were also decreased in the high-dose group, but not the low-dose group.

• No difference in the safety profile was observed between either group.

The outcomes

There are two major outcomes from this trial.  Firstly, they have shown that high-dose Vitamin D3 therapy appears to be safe in people with multiple sclerosis.  However, it must be considered that the study was only conducted over a 6-month period and so longer-term effects were not studied.  Secondly, they have shown that this high-dose protocol increases the levels of Vitamin D in the blood and has a potentially beneficial effect on the immune system.  Larger clinical trials are now underway that should determine whether a similar treatment plan results in improvements in symptoms and disability progression in people with MS.

The abstract of the study can be viewed here.