21st Conference on Retroviruses and Opportunistic Infections

Daily high-dose vitamin D and calcium supplements reduced total hip bone loss 50 % in a 48-week placebo-con-trolled trial that enrolled people starting efavirenz plus tenofovir/emtricitabine [1]. The 165-person ACTG A5280 trial left open questions about the vitamin D dose used and whether calcium is an essential part of the regimen. A 2 % to 6 % drop in bone mineral density (BMD) when people start antiretroviral therapy is a well-documented phe-nomenon and is especially concerning in people with other bone risk factors and those starting tenofovir. Efavirenz has been linked to lower vitamin D, essential for healthy bones. Plentiful research documents low vitamin D levels in people with HIV and in the general population. ACTG investigators conducted this double-blind placebo-controlled trial to determine whether 48 weeks of 4000 IU of vitamin D plus 1000 mg of calcium carbonate daily will ameliorate BMD loss in people starting efavirenz with tenofovir/emtricitabine. Participants had a DXA scan before starting antiretrovirals and again at 48 weeks. Partici-pants had to be antiretroviral naive and had to have a vitamin D level between 10 and 75 ng/mL. They could not be taking bisphosphonates or recent steroids or have a history of fragility fracture, kidney stones, or hypercalcemia. The 79 people randomized to vitamin D/calcium and the 86 randomized to placebo were similar in median age (3