Is there any way to know if I’m genetically susceptible to MS? If I am, should I take vitamin D preventatively?

While more than 100 genes^[1] have been associated with MS, it is hard to say just how predictive these markers are without taking into account environmental and lifestyle variables. Someone carrying the genes associated with increased risk of MS may never develop the disease. Alterations in the HLA-DRB1 gene^[2] have shown the strongest associated genetic risk factors for MS. HLA-DRB1 genes play a role in the immune system, which may help to explain why the pathology of the disease is closely tied to dysfunction of certain immune system components like interleukin-17. Currently, there are no reliable tests available for predicting the risk of MS. While ensuring adequate vitamin D levels is always a good idea, there is no conclusive evidence that it can decrease the risk of developing MS.