A commentary by Mayo Clinic Nephrologist Rajiv Kumar, M.D., in the current issue of the journal Kidney International suggests that Vitamin D may improve the treatment of renal disease. Dr. Kumar says that while larger clinical trials are needed, he believes doctors should start treating patients with diabetes who have low serum levels of 25-hydroxyvitamin (the active form of vitamin D) with vitamin D3 to help slow down the progression of kidney damage. Dr. Kumar cautions that more research is needed and that patients should always consult their doctors before consuming vitamin D supplements on their own.