- We will screen for these conditions by detailed history, physical exam (including dental exam), chart review, and baseline laboratory analyses, including BUN/creatinine, liver function tests, TSH, calcium, PTH, 25-hydroxyvitamin D, alkaline phosphatase and baseline calculated creatinine clearance. Participants with vitamin D levels < 20 ng/ml will be treated with vitamin D 50,000 IU/wk for 8 weeks in addition to calcium. Vitamin D will be rechecked and the patient will be enrolled if the vitamin D level is > 20 ng/ml.