Sub-Optimal Vitamin B-12 Levels among ART-Naïve HIV-Positive Individuals in an Urban Cohort in Uganda

Malnutrition is common among HIV-infected individuals and is often accompanied by low serum levels of micronutrients. Vitamin B-12 deficiency has been associated with various factors including faster HIV disease progression and CD4 depletion in resource-rich settings. To describe prevalence and factors associated with sub-optimal vitamin B-12 levels among HIV-infected antiretroviral therapy (ART) naïve adults in a resource-poor setting, we performed a cross-sectional study with a retrospective chart review among individuals attending either the Mulago-Mbarara teaching hospitals' Joint AIDS Program (MJAP) or the Infectious Diseases Institute (IDI) clinics, in Kampala, Uganda. Logistic regression was used to determine factors associated with sub-optimal vitamin B-12. The mean vitamin B-12 level was 384 pg/ml, normal range (200-900). Sub-optimal vitamin B-12 levels (<300 pg/ml) were found in 75/204 (36.8%). Twenty-one of 204 (10.3%) had vitamin B-12 deficiency (<200 pg/ml) while 54/204 (26.5%) had marginal depletion (200-300 pg/ml). Irritable mood was observed more among individuals with sub-optimal vitamin B-12 levels (OR 2.5, 95% CI; 1.1-5.6, P=0.03). Increasing MCV was associated with decreasing serum B-12 category; 86.9 fl (± 5.1) vs. 83 fl (± 8.4) vs. 82 fl (± 8.4) for B-12 deficiency, marginal and normal B-12 categories respectively (test for trend, P=0.017). Compared to normal B-12, individuals with vitamin B-12 deficiency had a longer known duration of HIV infection: 42.2 months (± 27.1) vs. 29.4 months (± 23.8; P=0.02). Participants eligible for ART (CD4<350 cells/µl) with sub-optimal B-12 had a higher mean rate of CD4 decline compared to counterparts with normal B-12; 118 (± 145) vs. 22 (± 115) cells/µl/year, P=0.01 respectively. The prevalence of a sub-optimal vitamin B-12 was high in this HIV-infected, ART-naïve adult clinic population in urban Uganda. We recommend prospective studies to further clarify the causal relationships of sub-optimal vitamin B-12, and explore the role of vitamin B-12 supplementation in immune recovery.