Objective:
Our interest in this study stems from its use of vitamin D as an intervention to treat probable vitamin D insufficiency and deficiency in African American adolescents. This poor vitamin D status is hypothesized to be a principal contributor to altered calcium metabolism that is negatively affecting bone health in these subjects. In addition to poor vitamin D status, the chronic inflammation of HIV is also postulated to have a detrimental effect on bone turnover in these subjects. In addition, some subjects in the study will be taking an antriretroviral drug (Tenovovir) that appears to have a detrimental effect on vitamin D metabolism, replicating what is seen in non-HIV-infected subjects with impaired kidney function. Thus examination of the interaction of kidney function and inflammation on vitamin D homeostasis in subjects with vitamin D insufficiency is a useful model to predict how subjects with other chronic inflammatory conditions (e.g., metabolic syndrome, type II diabetes) may benefit from vitamin D supplementation. The principal goal of the study is to determine if vitamin D supplements to treat vitamin D deficiency or insufficiency decrease bone turnover associated with chronic inflammation and a drug regimen with toxicity for kidney tubular epithelial cells, where 25OH vitamin D is converted to its active metabolite, calcitriol, for regulation of calcium homeostasis. The subjects in the study are primarily African American adolescents and are at increased risk of vitamin D insufficiency or deficiency due to skin pigmentation, low milk intake, and (possibly) low sun exposure.

Approach:
This is a multi-center study with the Aids Trial Network, a group Dr. Stephensen has worked with previously (when it was known as the REACH network). This is a randomized, placebo-controlled intervention with vitamin D to examine the impact of an ¿adolescent friendly¿ vitamin D supplementation regimen (50,000 IU per month in a single dose) to improve vitamin D status. If successful, this might be a useful approach for subjects at high risk of vitamin D insufficiency or deficiency for whom daily supplements or increased dietary intake of vitamin D are not anticipated to be effective in improving vitamin D status. This study may thus be useful in planning population-based strategies for dealing with the high prevalence of vitamin D deficiency in the US population, particularly in African Americans. Documents Trust with University of Alabama (National Institute of Child Health and Human Development). Log 33840.