 Adverse bone health is one of the major long-term complications among perinatally HIV-infected children and adolescents receiving ART. Since a great deal of bone mineral accrual occurs during the adolescent years and the peak attainment is usually seen at age 18 years, the loss of bone deposition during this period could lead to serious consequences, particularly increased risk of osteoporosis and bone fragility in later of life. A previous study demonstrated that prevalence of low BMD among perinatally HIV-infected Thai children and adolescents was high 25. However, the prevention strategies such as calcium and vitamin D supplementation which are widely recommended by many guidelines for preventing of osteoporosis and bone fracture have not been well studied to prove their effectiveness among HIV-infected children and adolescents, especially in resource-limited countries. This is considered as the critical research question in pediatric HIVAIDS field which are urgently required robust and in-depth investigations. 