The Effect of Vitamin D Statues on Endothelial Function

Exclusion Criteria

• •Current hypercalcemia (serum calcium \> 10.5 mg/dl) or untreated primary hyperparathyroidism.
• •History of nephrolithiasis
• •Baseline 24-hour urine calcium \> 250 mg
• •Known risk factors for hypercalcemia, e.g., malignancy, tuberculosis, sarcoidosis, Paget's disease.
• •History of any form of cancer within the past five years with the exception of adequately treated squamous cell or basal cell skin carcinoma.
• •Known previous personal history of cardiovascular disease.
• •Renal failure; defined as a calculated creatinine clearance (using the Cockroft-Gault approach) of ≤ 25 ml/minute.
• •Severe end-organ disease, e.g., cardiovascular, hepatic, hematologic, pulmonary, etc., which might limit the ability to complete this study.
• •Treatment with any drug known to interfere with vitamin D metabolism, e.g., phenytoin, phenobarbital.
• •Known malabsorption syndromes, e.g., celiac disease, active inflammatory bowel disease, etc.
• •Known allergy to chocolate.
• •Use of medications known to alter bone turnover including bisphosphonates, estrogen, selective estrogen receptor modulators, parathyroid hormone, testosterone or calcitonin.
• •Treatment with any active metabolites of vitamin D, e.g., calcitriol, within six months of screening.
• •Use of tanning beds or salons or unwillingness to utilize sunscreen during periods of sun exposure of 15 minutes or longer.