There are many possible causes of schizophrenia, including the role of genes and various environmental factors. There is also a lot of talk about the potential effects of vitamin D deficiency - it is pointed out that this condition can adversely affect the bones, but also the cardiovascular system and carbohydrate metabolism. It turns out that the two problems mentioned - i.e. schizophrenia and vitamin D deficiency - may have far more in common than one might think, as reported by researchers at Iran's Isfahan University of Medical Sciences.