Low vitamin D among HIV-infected adults: prevalence of and risk factors for low vitamin D Levels in a cohort of HIV-infected adults and comparison to prevalence among adults in the US general population.

Background: we explored serum 25-hydroxyvitamin D (25[OH]D) levels and associated factors for insufficiency or deficiency in an adult human immunodeficiency virus (HIV) cohort and compared 25(OH)D levels with those in the general US population.

Methods: using baseline data from the Study to Understand the Natural History of HIV and AIDS in the Era of Effective Therapy (SUN), a prospective, observational cohort study of HIV-infected adults enrolled at 7 HIV specialty clinics in 4 US cities from March 2004 to June 2006, we estimated the prevalence of vitamin D insufficiency or deficiency (defined as 25(OH)D levels <30 ng/mL), standardized by age, race, and sex. Using multiple logistic regression, we examined risk factors for vitamin D insufficiency or deficiency.

Results: among 672 SUN participants with baseline serum 25(OH)D determinations who were not receiving vitamin D supplements, 70.3% (95% confidence interval [CI], 68.1%-74.9%) were vitamin D insufficient or deficient, compared with 79.1% (95% CI, 76.7-81.3) of US adults. Factors associated with vitamin D insufficiency or deficiency included black race (adjusted odds ratio [aOR], 4.51; 95% CI, 2.59-7.85), Hispanic ethnicity (aOR, 2.78; 95% CI, 1.31-5.90), higher body mass index (aOR, 1.04; 95% CI, 1.00-1.09), hypertension (aOR, 1.88; 95% CI, 1.10-3.22), lack of exercise (aOR, 3.14; 95% CI, 1.80-5.47), exposure to efavirenz (aOR, 1.98; 95% CI, 1.18-3.34), higher exposure to ultraviolet light (aOR, .78; 95% CI, .71-.86), renal insufficiency (aOR, .55; 95% CI, .36-.83), and exposure to ritonavir (aOR, .56; 95% CI, .35-0.89).

Conclusions: similar to findings in US adults generally, vitamin D insufficiency or deficiency is highly prevalent among HIV-infected adults and is associated with known risk factors. Observed associations of vitamin D levels with renal insufficiency and with use of ritonavir- and efavirenz-containing regimens are consistent with both HIV-related and therapy-mediated alterations in vitamin D metabolism. Clinicians should consider screening all patients for vitamin D insufficiency or deficiency.