To determine the prevalence of hypovitaminosis D in HIV infected patients, and the consequences on secondary hyperparathyroidism, and bone mineral density (BMD). Also, to establish the improvement in vitamin D status, parathyroid hormone (PTH) and BMD, in case of receiving vitamin D supplementation, during a follow up period of at least 1 year.

This study deals with the impact of vitamin D on metabolism and bone health in HIV infected patients. To answer the questions about the importance of this hormone in this population, we designed a cohort study about the prevalence of vitamin D deficiency (measured as 25-hydroxy-vitamin D), classifying it in severe deficiency (<10 ng/ml), deficiency (< 20 ng/ml), or insufficiency (< 30 ng/ml), the relationship with secondary hyperparathyroidism (PTH > 65 pg/ml), and related BMD by dual X-ray absorptiometry (DXA). These results will be adjusted by baseline factors, such as age, gender, body mass index (BMI), hepatitis C virus (HCV) coinfection, risk practice for HIV infection, CD4+ count, antiretroviral therapy, and HIV RNA level.

In patients receiving vitamin D supplementation according to clinical decision, it will be evaluated the changes in percentage of hypovitaminosis D and/or secondary hyperparathyroidism, and the effect on BMD. Bone biomarkers will be collected to determine the impact of changes secondary to vitamin D improvement in the bone evolution.

Inclusion Criteria:

• HIV older than 18 years

Exclusion Criteria:

• Chronic kidney disease stage 4 and 5 (creatinine clearance < 30 ml/min)
• Pregnancy
• Uso of corticosteroid therapy, or requiring anti-resorptive treatment
• Prolonged hospitalization or internment

HIV-infected patients in follow up