Vitamin D2 is a fat soluble steroid hormone precursor which must be hydroxylated in the liver and kidney respectively to make the active form 1-25-Vitamin D. This active metabolite and related analogs have been synthesized and are frequently used in the treatment of hyperparathyroidism in patients with chronic kidney disease. However the active metabolite may not be back metabolized to the precursor forms which may have functions in other organs including the skin. Supplementation of hemodialysis patients with oral vitamin D forms would provide a source of precursors for use throughout the body.