Background: Vitamin D deficiency is of increasing concern in HIV-infected persons because of its reported association with a number of negative health outcomes that are common in HIV. We undertook this study to determine the prevalence and predictors of vitamin D deficiency among a nationally representative cohort of middle-aged, ethnically diverse, HIV-infected and HIV-uninfected women enrolled in the Women's Interagency HIV Study (WIHS).
Methods: Vitamin D testing was performed by Quest Diagnostics on frozen sera using the liquid chromatography/mass spectroscopy method. Vitamin D deficiency was defined as 25(OH)D ≤20 ng/mL. Comparisons of continuous and categorical characteristics among HIV-infected and HIV-uninfected women were made by Wilcoxon tests and Pearson χ tests, respectively.
Results: One thousand seven hundred seventy-eight women (1268 HIV positive) were studied. Sixty-three percent had vitamin D deficiency (60% HIV positive vs. 72% HIV negative; P < 0.001). Multivariable predictors of vitamin D deficiency were being African American (adjusted odds ratio 3.02), Hispanic (adjusted odds ratio 1.40), body mass index (adjusted odds ratio 1.43), age (adjusted odds ratio 0.84), HIV positive (adjusted odds ratio 0.76), glomerular filtration rate <90·mL·min (adjusted odds ratio 0.94), and WIHS sites Los Angeles (adjusted odds ratio 0.66) and Chicago (adjusted odds ratio 0.63). In the HIV-positive women, multivariate predictors were undetectable HIV RNA (adjusted odds ratio 0.69), CD4 50-200 cells per cubic millimeter (adjusted odds ratio 1.60), CD4 <50 cells per cubic millimeter (adjusted odds ratio 1.94), and recent protease inhibitor use (adjusted odds ratio 0.67).
Conclusions: In this study of more than 1700 women in the United States, most women with or without HIV infection had low vitamin D levels and African American women had the highest rates of vitamin D deficiency. An understanding of the role that vitamin D deficiency plays in non-AIDS-related morbidities is planned for investigation in WIHS.