Tenofovir disoproxil fumarate (TDF) is a nucleotide analogue reverse transcriptase inhibitor, has been associated with greater bone loss than other reverse transcriptase inhibitors, that is recommended as the first line treatment in Thailand. Nonetheless there is an evidence in western country that calcium and vitamin D supplement can attenuate bone loss in naive HIV-infected individual who start ART with TDF. Even though many experts recommend to avoid TDF and prefer abacavir, NRTIs which affect bone loss less than other NRTIs, in high fracture risk patients, more than less HIV-infected-patients can access to abacavir in resource limiting country. This research aims to study bone mineral density (BMD) in HIV infected-patient in Thai population who receive tenofovir with calcium and vitamin D supplement.