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

(See the editorial commentary by Yin and Stein, on pages 406–408.)Background. We explored serum 25-hydroxyvitamin D (25[OH]D) levels and associated factors forinsufficiency or deficiency in an adult human immunodeficiency virus (HIV) cohort and compared 25(OH)Dlevels with those in the general US population.Methods. Usingbaseline datafrom theStudytoUnderstandtheNaturalHistory ofHIVandAIDSintheEraofEffective Therapy (SUN), a prospective, observational cohort study of HIV-infected adults enrolled at 7 HIVspecialtyclinicsin4UScitiesfromMarch2004toJune2006,weestimatedtheprevalenceofvitaminDinsufficiencyor deficiency (defined as 25(OH)D levels ,30 ng/mL), standardized by age, race, and sex. Using multiple logisticregression, we examined risk factors for vitamin D insufficiency or deficiency.Results. Among672SUNparticipantswithbaselineserum25(OH)DdeterminationswhowerenotreceivingvitaminD supplements, 70.3% (95% confidence interval [CI], 68.1%– 74.9%) were vitamin D insuffi cient or deficient, comparedwith79.1%(95%CI,76.7–81.3)ofUSadults.Factorsassociat edwithvitaminDinsufficiencyordeficiencyincludedblackrace(adjustedoddsratio[aOR],4.51;95%CI,2.59–7.85),Hispanicethnicity(aOR,2.78;95%CI,1.31–5.90),higherbodymassindex(aOR,1.04;95%CI,1.00–1.09),hypertension(aOR,1.88;95%CI,1.10–3.22),lackofexercise(aOR,3.14;95%CI,1.80–5.47),exposuretoefavirenz(aOR,1.98;95%CI,1.18–3.34),higherexposuretoultravioletlight(aOR,.78;95%CI,.71–.86),renalinsufficiency(aOR,.55;95%CI,.36–.83),andexposuretoritonavir(aOR,.56;95%CI,.35–0.89).Conclusions. SimilartofindingsinUSadultsgenerally,vitaminDinsufficiencyordeficiencyishighlyprevalentamongHIV-infectedadultsandisassociatedwithknownriskfactors.ObservedassociationsofvitaminDlevelswithrenal insufficiency and with use of ritonavir- and efavirenz-containing regimens are consistent with both HIV-relatedandtherapy-mediatedalterationsin vitaminDmetabolism. Cliniciansshouldconsiderscreening allpatientsfor vitamin D insufficiency or deficiency.Vitamin D is essential for calcium homeostasis and bonemetabolism [1]. Vitamin D deficiency is associated witha number of comorbidities, including hypertension,cardiovascular disease, insulin resistance, diabetes, dysli-pidemia, impaired immune function, decreased neuro-cognitive function, and malignancies [2–6]. The primarydeterminant of vitamin D status is exposure to sunlight.With increasing urbanizationand sunscreen use, vitaminD deficiency has become highly prevalent among thegeneral population [7, 8].Currently, serum concentration of 25-hydrox-yvitamin D (25[OH]D) is considered the best indicatorof vitamin D status, because it represents cumulative