Background: Multiple sclerosis is a disease of the central nervous system characterized by demyelination of the nerve sheaths which can result in varying levels of disability. Disease occurrence and progression are considered by some to be associated with low serum levels of vitamin D. Studies investigating vitamin D supplementation in MS patients have illustrated a noticeable improvement in the course of the disease.
Objectives: To evaluate the safety and effectiveness of vitamin D in the management of multiple sclerosis.
Search strategy: We searched the Cochrane Multiple Sclerosis Group Trials Register comprising references identified from comprehensive electronic database searches and hand searches of relevant journals and abstract books of conferences.
Selection criteria: Randomised and quasi-randomised controlled trials comparing vitamin D with placebo or any other treatment for the management of multiple sclerosis.
Data collection and analysis: Two review authors selected trials for inclusion, assessed the risk of bias and extracted data independently. Disagreements were resolved by consensus. Trialists were contacted for clarification of study details.
Main results: We included a single trial (49 participants) conducted over 52 weeks, which treated 25 patients with escalating doses of vitamin D compared with control (24). The trial provided some evidence of the potential benefit of the intervention on several outcomes i.e. the annualised relapse rate; EDSS scores; suppression of T-cell proliferation and illustrated a measure of comparative safety in the relative absence of any adverse events or of high serum calcium levels over the study period. This was a low powered trial with a potential high risk of bias which may ultimately impose limits on the applicability of the available evidence to the MS population as a whole.
Authors' conclusions: The current level of evidence for the effectiveness of vitamin D supplementation in the management of people with MS is based on a single RCT with potential high risk of bias, which does not at present allow confident decision-making about the use of Vitamin D in MS. Therefore, until further high quality evidence is available, clinicians may wish to consider relevant MS guidelines on vitamin D supplementation when making decisions about the care of people with multiple sclerosis. Adequately powered, multi-centred RCTs with a focus on clinical as well as immunological and MRI outcomes that are meaningful to people with MS, and are able to provide insight into the benefits of Vitamin D in people with MS, are still required.