Vitamin D and interferon-beta treatments in MS
30th July, 2012
There is a link between vitamin D and MS, with higher levels of vitamin D shown to guard against the development of MS in children and young adults. Three recent papers published in the same issue of the journal Neurology, have investigated this relationship further. The first paper confirmed that lower levels of vitamin D are also associated with a higher number of relapses in people with MS. Runia and colleagues followed 73 people with MS for 1.7 years and measured vitamin D levels every eight weeks. The team found that doubling the vitamin D level decreased the rate of relapse by 27%. A key strength of this study is the frequent measurements of vitamin D in study participants.
The two other studies looked at the interaction between vitamin D and interferon-beta treatment in people with MS. One study led by Prof Bruce Taylor from the Menzies Research Institute in Tasmania examined 178 people over more than two years and reported a reduced rate of relapse in people with higher levels of vitamin D and that this was modulated by interferon-beta. The authors found that people on interferon-beta produced more vitamin D from the same amount of sunshine than those not on treatments and suggested that one way in which interferon beta works is via changes in vitamin D metabolism. ‘Importantly, interferon-beta was only protective against relapse among people with higher levels of vitamin D’, explained Prof Taylor, ‘while among people who had insufficient levels of vitamin D, interferon-beta treatment increased relapse risk’.
A further news items on this study can be found here.
The other study from scientists in Norway, has shown that higher levels of vitamin D reduce the number of new lesions detected by magnetic resonance imaging (MRI) in 88 people with relapsing remitting MS. The study recorded vitamin D measurements before and after starting interferon-beta treatment. In contrast to the Australian study, the protective effect of vitamin D was observed prior to starting interferon-beta treatment, but the effect disappeared once the interferon-beta treatment began.
One reason for the different results in these two studies may be location, in particular the distance from the equator, but the timing of the vitamin D measurements and control of other variables may also have contributed to the conflicting findings. Controlling variables in studies of vitamin D such as season, and sun exposure are important to determine the true causative factor.
MSRA is sponsoring a clinical trial designed to test whether vitamin D supplementation can prevent a subsequent diagnosis of MS in people who have experienced their first demyelinating event, PrevANZ. The trial is due to begin later in 2012. PrevANZ is a collaborative study between clinicians and researchers in Australia and New Zealand and has been designed to control for other factors such as sunshine exposure in order to ensure the results are as robust as possible. ‘The three observational articles published this week add to the increasing evidence to support a link between vitamin D and MS’, said Prof Taylor, ‘there is a clear need for well conducted prospective intervention trials such as PrevANZ’. Further details regarding recruitment for PrevANZ will be published on this website and its sister website, www.mstrials.org.au, once they are available.