This study will compare and assess the prevalence of osteopenia and vitamin D deficiency as well as effects of TDF on the patients' bone among HIV positive and negative patients.

To determine the prevalence of osteopenia and vitamin D deficiency in HIV-1 infected, HAART naive Thai patients compared to HIV-1 uninfected Thai participants. Furthermore, to determine the change in BMD after twelve months in HIV-1 infected Thai patients on a TDF-based HAART regimen compared to patients on a non-TDF containing regimen.

Inclusion Criteria:

• HIV uninfected:

  • HIV negative confirmed by HIV testing
  • Age 30 years and older
  • Thai nationality
  • Signed informed consent form for the study

• HIV-infected, HAART naïve:

  • Recorded HIV infection
  • Age 30 years and older
  • Thai nationality
  • Signed informed consent form for the study

• HIV-infected, HAART group:

  • Recorded HIV infection
  • Age 30 years and older
  • Thai nationality
  • HAART naïve at baseline, planned to start HAART within 90 days. Past exposure to antiretroviral therapy during pregnancy for the prevention of mother to child transmission of HIV ≥ 3 months prior to screening will be allowed
  • Signed informed consent form for the study

Exclusion Criteria:

• HIV uninfected

  • Currently pregnant or lactating
  • Recent hospitalization
  • Use of anticonvulsants, steroids or vitamin D supplements

• HIV-infected, HAART naïve

  • CD4 < 350
  • Currently pregnant/lactating
  • Recent hospitalization
  • Signs of wasting
  • Use of anticonvulsants, steroids or vitamin D supplements

• HIV-infected, HAART group:

  • Prior antiretroviral therapy use
  • Currently pregnant/lactating
  • Recent hospitalization
  • Signs of wasting
  • Active opportunistic infection
  • Use of anticonvulsants, steroids or vitamin D supplements

All participants are from the Anonymous Clinic of the Thai Red Cross AIDS Research Centre (TRC-ARC, the HIV Netherlands Australia Thailand Research Collaboration (HIVNAT) and Queen Savang Vadhana Memorial Hospital (QSV).