A randomized trial of high-dose vitamin D2 in relapsing-remitting multiple sclerosis.
OBJECTIVE: Higher latitude, lower ultraviolet exposure, and lower serum 25-hydroxyvitamin D (25OHD) correlate with higher multiple sclerosis (MS) prevalence, relapse rate, and mortality. We therefore evaluated the effects of high-dose vitamin D2 (D2) in MS.
“This study is the first published randomised double blind controlled trial of vitamin D supplementation in MS. Disappointingly it did not show that taking higher doses of vitamin D can protect against MS disease activity. However, several features of this study mean that further work is still needed to test whether vitamin D is an effective treatment or not. This study was very small (20 patients- as compared to trials such as Alemtuzumab using 500- the more patients you have the more likely you are able to see whether a treatment works); both groups of patients were taking more vitamin D than the UK Government recommend per day (6000IU of vitamin D a day versus 1000IU) so the control group may have had some protection as well; the study was run for 6 months which is thought to be too short to really say whether there is a meaningful effect of treatment, and the investigators used vitamin D2 instead of the more active D3. All of this being said, the study raises the question of whether vitamin D deficiency is only involved in triggering MS and not in how the disease progresses; but we need to test this appropriately.”
Why did the researchers choose D2 rather than D3? It seems to be a poor bit of research (23 people) to base a conclusion on.
Agreed! To be honest, there is little point to this study. When performing a clinical trial, a genetic or an epidemiological study researchers need to decide on what the power of the study needs to be (i.e. how many people need to be investigated). For clinical trials it is probably more than 500, for genetic studies this needs to be thousands. Better trials for vitamin D on their way.