 This randomized clinical trial study will provide important information about the effect of calcium and high dose comparing to normal dose vitamin D supplementation on BMD among ART-experienced, perinatally acquired HIV-infected children and adolescents to best understand the relative contributions of the supplementation to improve bone health status. This study will address research questions, fill gaps in knowledge, and draw clinician attentions to the important long-term medical complications in children and adolescents who are growing up with HIV. Moreover, this study will inform healthcare providers and policy makers about the importance of calcium and vitamin D supplementation as one of the measurement to prevent long-term deterioration of bone mass and the mean to promote bone health among these populations. 