ACTUAL CLINICAL USES OF D. “Vitamin D is used for conditions of skin conditions including vitiligo, scleroderma, psoriasis, actinic keratosis, and lupus vulgaris … boosting the immune system, preventing autoimmune diseases, and preventing cancer.”
http://www.webmd.com/vitamins-supplements/ingredientmono-929-vitamin%20d.aspx?activeingredientid=929&activeingredientname=vitamin%20d/