Hey joelawerence, I'm in a similar situation to you in that most supplements do not have much affect on my POIS, but vitamin D has helped me considerably. I started on the vitamin D because I found out from 23andme that I had a mutation in my vitamin d receptor, and since then my immune system, fatigue and length of POIS have all improved quite a bit. I suspect this is due to the fact that vitamin D is a steroid, immunosuppressive, helps promote regulatory T cells, and because I was probably deficient in Vitamin D like the majority of people and probably an even larger majority of people with POIS.
Low levels of vitamin D have been implicated in a large number of autoimmune diseases, and although there is debate to whether it causes autoimmune diseases or if low levels are a result of autoimmune diseases, I think it will help with POIS.
From
http://www.amymyersmd.com/2016/06/vitamin-d/One study found that insufficient levels of Vitamin D have been reported in 36% of healthy adolescents and 57% of adults in the U.S. Other studies estimate that one billion people worldwide have insufficient Vitamin D levels. However, the rate of true Vitamin D deficiency is likely even higher, because new research indicates that the previous recommended levels of Vitamin D were actually too low.
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Autoimmune diseases arise when your immune system is confused or overly stressed and begins attacking your own tissues instead of outside pathogens. Vitamin D prevents this by promoting regulatory T cells, which are responsible for accurately differentiating between outside invaders and ?self? cells. When active Vitamin D promotes them, it essentially makes your immune system smarter, teaching it to not attack itself and preventing the development of an autoimmune disease.
Research in this area is relatively recent, but there are a number of studies demonstrating higher rates of autoimmune disease, as well as a greater rate of autoimmune disease progression, among people with Vitamin D deficiency. Studies have linked Vitamin D deficiency with Multiple Sclerosis, Lupus, Rheumatoid Arthritis, and Type I Diabetes.
