Two recent studies have been published further supporting the OMS position on maintaining a vitamin D level in the band of 150-225 nmol/L.


Study 1 


The first is a small study from Ireland. Investigators looked at the effect of supplementing healthy volunteers with doses of 5,000 and 10,000 IU of vitamin D3. This was performed in preparation for a prospective study of vitamin D3 supplementation in people with a Clinically Isolated Syndrome (CIS).


As would be expected, given the location of the study, all subjects were low in vitamin D3 at the beginning of the study with an average level 38 nmol/L.


All four participants took 5,000 IU daily for 10 weeks, then two participants increased their dose to 10,000 IU and the other two continued at 5,000IU for the following 5 weeks.


Those on 5,000 IU achieved maximum levels of 152 and 191 nmol/L while those on 10,000 IU had peak levels of 152 and 223 nmol/L.


Note that all these levels are within the normal range for vitamin D (75-225 nmol/L). To assess the effect on immune function the investigators measured the production of the anti-inflammatory cytokine IL-10 and the activity of pro-inflammatory Th17 cells (Th17 cells have an important role in the animal model of MS and are associated with disease activity).


They found that following supplementation with D3 there was a “striking” increase in production of the anti-inflammatory IL-10 and a significant decrease in activity of the pro-inflammatory Th17 cells.


These responses increased over the course of the study and were increased in the higher dose group. So this study confirms that high dose vitamin D3 does exactly what we are aiming at in modulating the immune response in people with MS so that inflammatory episodes are less likely.


Study 2


A further blinded randomised controlled trial has been published from Norway in which PwMS were supplemented with a low dose (20,000 IU/ week or under 3,000 IU/ day) of vitamin D3.


There were 35 patients in the treatment group and 33 in the placebo group and they were followed up for 96 weeks. The make up of subjects appeared similar in the two groups.  


The trial was originally designed to look at the effects on bone density so not powered (that is, there were not enough subjects in the study to detect an effect) to properly assess clinical outcomes. 


However it failed to show any improvements or trends to improving outcomes. Of importance to those following the OMS program, the median level of D3 reached was 123 nmol/L (highest 133 nmol/L) in the treatment group and 61.8 nmol/L in the control group.


These were the figures at 96 weeks – the results during the study are not given. There was no one-off dose to boost patients levels so it would appear that all patients were under-treated for the duration of the study.


The authors acknowledge the effect of the small sample size and that other studies which have suggested a relapse – reducing effect achieved higher levels of vitamin D.


They go on to suggest that further studies of vitamin D are required. Whilst we are awaiting these studies the results from trials overall fit the OMS recommendation of maintaining a vitamin D3 level of 150-225 nmol/L.


As we have long said, not only is this likely to reduce disease activity in MS, it is likely to have multiple helpful side effects, including reducing the likelihood of various cancers, depression, autoimmune conditions and cardiovascular disease.