There is ample evidence that improvement in vitamin D nutrition retards bone loss and prevents fractures in the elderly. It is clear that many people living in areas of northern latitude have less than optimal levels of vitamin D. The current recommendations for vitamin D intake are not enough to bring a large majority of the population to the desired adequate level. Furthermore, differences have been observed in the amount of Vitamin D produced in the skin in whites and blacks.~Based on the evidence from literature and our experience from prior studies we hypothesize that:~the dose of oral vitamin D3 supplement exceeds current recommendations to achieve adequate desired level;~there may be differences in the dose-response to vitamin D supplement between Blacks and Whites; and~vitamin D supplementation that produces serum 25-hydroxyvitamin D (25-OHD) levels in the range proposed is safe.~The aims for this pilot study are to determine:~the average dose of vitamin D3 needed to attain 25-OHD levels between 80-140 nmol/L in a healthy population of mixed races; and~if there are differences in response to vitamin D3 supplementation between African American and Caucasians subjects.
The purpose of this study is to determine the average dosage of oral vitamin D supplementation to maintain optimal vitamin D levels in the body and to see if there are differences in the response to oral vitamin D supplementation between African-American and Caucasian subjects.