 Patients with Chronic Kidney Disease CKD are upto 3.5 times more likely to die from diseases of heart and blood vessels Cardiovascular Disease-CVD. Vitamin D insufficiency is very common in CKD and associated with CVD. Animal studies have shown an improvement in heart size and function with Vitamin D therapy, although evidence in humans is lacking. The proposed study will test if oral Vitamin D treatment, in deficient CKD patients, will improve heart enlargement and function. With these proposed changes the investigators expect to reduce CVD and deaths in patients with CKD. 