Letters to the Editor
To the Editors:
We read the article by Adeyemi et al with interest1 because we had recently conducted similar analyses at our site using data from an HIV+ cohort followed at the HIV Outpatient Program based at the Interim Louisiana State Hospital and an HIV− population of women who were evaluated at 2 sexually transmitted disease clinics, one of each located in the states of Louisiana and Mississippi. Data on 90 HIV+ and 286 HIV− women were collected between October 2006 and December 2010. The data from HIV− women were limited to vitamin D levels, race, and age, but several additional variables of interest were available on HIV+ women.
HIV+ women were significantly older than HIV− women (mean age = 49.1 years ± 11.9, median = 49 years vs. 27.8 years ± 4.71, median = 27 years; P < 0.0001), but the 2 groups were racially similar (94.4% African American in HIV− vs. 93.3% African American in HIV+; P = 0.8). In our analysis, 263 of 376 (69.9%) women had vitamin D levels <20 ng/mL. The proportions of HIV+ (63 of 90, 70.0%) and HIV− women (200 of 286, 69.9%) with vitamin D levels <20 ng/mL were the same. In combined study population (HIV+ and HIV− women), the proportion of African American women with vitamin D levels <20 ng/mL was significantly higher than non African American women (71.7% vs. 40.9%, P = 0.002). Among women with vitamin D <20 ng/mL, 81.4% were under 40 years of age, 8.7% were between 40 and 50 years, and 9.9% were older than 50 years of age. African American race [adjusted odds ratio (OR) = 3.81, 95% confidence interval (CI) = 1.57 to 9.22; P = 0.003] remained significantly associated with vitamin D levels <20 ng/mL in a logistic regression analysis controlling for age (adjusted OR = 0.97, 95% CI = 0.94 to 1.01; P = 0.12) and HIV status (adjusted OR = 1.78, 95% CI = 0.73 to 4.35; P = 0.20).
In logistic regression analyses confined to HIV+ women, body mass index (BMI) <18.5 kg/m2 (adjusted OR = 0.03, 95% CI = 0.001 to 0.67; P = 0.03) and previous vitamin D supplementation (adjusted OR = 0.22, 95% CI = 0.06 to 0.81; P = 0.02) significantly predicted vitamin D levels >20 ng/mL,whereas CD4 count <500 cells per cubic millimeter significantly predicted vitamin D levels <20 ng/mL (adjusted OR = 3.60, 95% CI = 1.03 to 12.56; P = 0.04). Tenofovir use (adjusted OR = 3.69, 95% CI = 0.97 to 14.08; P = 0.06) weakly predicted vitamin D levels <20 ng/mL.
Our results are consistent with those found by Adeyemi et al.1 The prevalence of vitamin D deficiency (vitamin D levels <20 ng/mL) among HIV− women were similar (70.0% in our study and 71.8% in the Women's Interagency HIV Study [WIHS]), and among HIV+ women, the prevalence of vitamin D deficiency in our study (70%) and in the WIHS cohort (60%) were within the 45%–87% range reported in several studies of vitamin D levels among individuals infected with HIV.2–4 In the study by Adeyemi et al1 and in our study, African American race and high BMI were significant predictors of vitamin D deficiency. These findings were not unexpected because African American race2–4 and high BMI5,6 have been shown to be risk factors for vitamin D deficiency in the general population.7,8 Among HIV+ women, lower CD4 count remained an independent significant predictor of vitamin D deficiency in the WIHS and our cohorts. HIV infection in our study was not a significant predictor of vitamin D levels. This was also consistent with the lack of independent significant association of HIV infection with vitamin D levels in the WIHS cohort when vitamin D was modeled as a continuous variable.1 The findings from the WIHS cohort of significant associations of geographic locations with vitamin D deficiency1 suggest that additional studies from other geographic areas with diverse populations are warranted to evaluate predictors for low vitamin D levels both in the general population and among HIV+ individuals.
1. Adeyemi OM, Agniel D, French AL, et al.. Vitamin D deficiency in HIV-infected and HIV-uninfected women in the United States. J Acquir Immune Defic Syndr. 2011;57:197–204.
2. Van Den Bout-Van Den Beukel CD, Fievez L, Michels M, et al.. Vitamin D deficiency among HIV type 1-infected individuals in the Netherlands: effects of antiretroviral therapy. AIDS Res Hum Retroviruses. 2008;24:1375–1382.
3. Rodriguez M, et al.. High frequency of vitamin D deficiency in ambulatory HIV-Positive patients. AIDS Res Hum Retroviruses. 2009;25:9–14.
4. Dao CN, et al.. 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. Clin Infect Dis. 2011;52:396–405.
5. Wortsman J, et al.. Decreased bioavailability of vitamin D in obesity. Am J Clin Nutr. 2000;72:690–693.
6. Freedman BI, et al.. Vitamin d, adiposity, and calcified atherosclerotic plaque in african-americans. J Clin Endocrinol Metab. 2010;95:1076–1083.
7. Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357:266–281.
8. Holick MF, Chen TC. Vitamin D deficiency: a worldwide problem with health consequences. Am J Clin Nutr. 2008;87:1080S–1086S.