2. Objectives

1. To determine the vitamin D status of African-American HIV patients who are HIV-treatment naïve.
2. To compare the effects of an efavirenz-containing regimen to a protease inhibitor regimen on 25-hydroxyvitamin D and 1,25 dihydroxyvitamin D3 levels.
3. To compare the effect on bone density of a tenofovir- and efavirenz-containing regimen to a regimen that does not contain these drugs.
4. To compare the efficacy of an alternative regimen (raltegravir, darunavir, ritonavir) to a standard once-daily regimen (tenofovir-emtricitabine-efavirenz).

Hypothesis

The investigators hypothesize that patients receiving efavirenz will be more likely to have lower 25-hydroxyvitamin D and 1,25 dihydroxyvitamin D3levels based on the fact that efavirenz is an inducer of CYP3A4 and CYP24 enzymes that degrade 25-hydroxyvitamin D and 1,25 dihydroxyvitamin D3, respectively, to inactive metabolites. The investigators speculate that patients on a tenofovir-containing regimen will be more likely to have progression of bone density loss compared to those in the non-tenofovir-containing regimen.

Inclusion Criteria:

• age between 18 and 50 years old
• HIV infection and HIV RNA > 4000 copies/ml of plasma

Exclusion Criteria:

• known risks for osteoporosis, including low body mass index (BMI < 20)
• chronic alcohol use
• chronic steroid use
• use of phenytoin or phenobarbital
• chronic renal insufficiency (calculated glomerular filtration rate < 50 ml/min)
• males with testosterone deficiency, and post-menopausal females will be excluded