Abstract
As [David Gurwitz] and [Abraham Weizman] suggest, vitamin D or vitamin D analogues may prove to be a useful treatment for type 1 diabetes and other autoimmune diseases. In a broader context, the observed association between vitamin D intake and development of type 1 diabetes raises the issue of the optimum physiological concentration of vitamin D in human beings. To date there is no consensus about the definition of vitamin D deficiency or any generally accepted reference values for the optimum range of serum values.4 Toxicity of vitamin D is very well established, thus excessive vitamin D intake is likely to have harmful rather than beneficial long-- term health effects. However, if vitamin D status is lower than that required for normal function of the human immune system, it is likely to affect the development of many other diseases in addition to those of autoimmune origin.