Hyperlactatemia is a serious complication of NRTI treatment for HIV. Most physicians temporarily discontinue antiretroviral therapy in patients with serious hyperlactatemia, then restart antiretrovirals after lactate levels normalize. Two options for restarting antiretrovirals are to switch to different NRTIs or switch to an NRTI-sparing regimen. The latter option is probably safer, but a growing number of the HIV-infected population has already been exposed to all available classes of antiretrovirals and may lack this option. This study will investigate the ability of antioxidants and B vitamins to prevent the recurrence of hyperlactatemia in patients who restart the same NRTI-containing regimen.