Vitamin D has a critical role in bone metabolism. In addition, there is increasing evidence that vitamin D has an important role in many other areas, including cardiovascular health, immune function, and prevention of autoimmune diseases and certain malignancies. In patients with CKD, there are a variety of abnormalities in mineral metabolism that lead to bone disease.
After the investigators obtain informed consent and assent, children will be randomly assigned to either low dose (1000 units daily) or high dose (4000 units daily) vitamin D pills (50% in each group). Participants will take vitamin D capsules every day for for 6 months. Vitamin D levels will be obtained at baseline, 3 months and 6 months. The study visits will be at the same time as routine clinic visits when the children are having blood drawn for routine care. At the end of the study, the investigators will compare the percentage of patients who have normal vitamin D levels at 6 months in the two groups. The investigators will also describe the percentage of patients who have elevated or low levels of trace elements.
The two doses of vitamin D in this study are within the dosing range recommended by the Institute of Medicine, and thus the investigators do not anticipate any adverse effects. Vitamin D toxicity could theoretically occur, and an elevated vitamin D level at 3 months would be an indication to withdraw a patient from the study.
