Vitamin D Inadequacy in Rural Populations, Evaluation of Correction by Food Supplementation

Inclusion criteria: * Healthy, community-dwelling ambulatory women. * Able and willing to sign informed consent. * Ages: 20-30, 55-65 or \>75 * Baseline serum 25OHD concentration \> 10 ng/ml and \< 60 ng/ml * Not pregnant * Willing to avoid use of cod-liver oil and non-study vitamin D supplementation; standard multiple vitamins containing ≤ 400 IU used no more than once daily will be allowed. * Willing to utilize sunscreen of SPF-15 or higher when sun exposure for more than 15 minutes is expected. 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. * 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 high dose vitamin D (≥ 50,000 IU weekly) or 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.