Multivitamin supplements have no effect on growth of tanzanian children born to HIV-infected mothers

Growth faltering and micronutrient deficiencies commonly coexist in HIV-exposed children in sub-Saharan Africa, and correcting deficiencies, such as those of vitamins B-complex, C, and E, may improve HIV-related endpoints and child growth. We therefore examined the effect of daily oral supplementation of vitamins B-complex, C, and E on growth among 2341 children born to HIV-infected mothers in Tanzania. HIV-infected women pregnant at ≤32 wk of gestation were enrolled in the study. Children were randomized at age 6 wk to receive multivitamins or placebo until age 104 wk. All women received the same types of vitamins pre- and postnatally. At 6 wk, 256 children (11.1%) were HIV infected and the mean (SD) Z-scores for length for age (LAZ), weight for length (WLZ), and weight for age (WAZ) were -0.39 ± 1.20, -0.21 ± 1.23, and -0.52 ± 1.11, respectively. There was no overall treatment effect on LAZ, WLZ, or WAZ profiles during the follow-up (P≥0.15). There was no treatment effect from 6 to 104 wk on LAZ [(95% CI:-0.14, 0.13); P = 0.94], WLZ [(95% CI: -0.17, 0.13); P = 0.78], or WAZ [(95% CI: -0.15, 0.16); P = 0.97] or on the incidence of growth failure, defined as respective Z-scores < -2 (P ≥ 0.29). Among the subgroup of HIV-uninfected children, there was no treatment effect from 6 to 104 wk on LAZ, WLZ, and WAZ (P ≥ 0.71) or on the incidence of growth failure (P ≥ 0.16). Multivitamin supplements had no effect on growth among children born to HIV-infected women whowere themselves receiving multivitamins. © 2013 American Society for Nutrition. Details of the trial were described elsewhere (24). In brief, pregnant women who provided written informed consent were invited to enroll in the study and were followed up throughout the antenatal, delivery, and postnatal periods to assess whether the mother-infant pair met the eligibility criteria for the child to be randomized at age 5–7 wk. The study regimen contained 60 mg vitamin C, 8 mg vitamin E, 0.5 mg thiamine, 0.6 mg riboflavin, 4 mg niacin, 0.6 mg vitamin B-6, 130 μg folate, and 1 mg vitamin B-12. Children <6 mo received 1 capsule and older children 2 capsules/d. The dosages administered represent 150–600% and 200–400% of the US Adequate Intake for children aged 0–6 mo and 7–12 mo, respectively, and 133–800% of the US RDA for children aged 1–3 y. For these nutrients, tolerable upper intake levels have not been defined for children <12 mo; the tolerable upper intake levels (if defined) were not exceeded for children ≥12 mo (25, 26). The regimen was provided to caretakers in addition to small, disposable plastic dosing cups and containers holding 5 mL of sterile water. At monthly visits, the caretakers received the number of capsules, cups, and water containers required for the upcoming month in addition to a surplus to allow for continued administration of the regimen if the caretakers returned late to the study clinic. Those traveling out of Dar es Salaam were provided with sufficient regimen and supplies until the next scheduled research visit. Caretakers were instructed on how to push the capsule through the back of the blister pack, open it, decant the powder into the cup, add the sterile water to the powder, and observe the child consuming the full content of the cup. The study statistician (R.J.B., based in Boston, MA) prepared a computer-generated randomization list using permuted blocks of size 20. Onsite study pharmacists stored the coded randomization list in a locked file cabinet and concealed the allocation by covering the numeric regimen code on each blister pack with a sticker. Infants enrolled at the study clinic were provided the next consecutive number in the series. Study physicians, research nurses, and participants were unaware of the assignment groups. The supplement used was a powder encapsulated in an opaque gelatinous capsule manufactured by Nutriset, which was not involved in the study design, implementation, analysis, or reporting of findings. The study protocol was approved by the Institutional Review Boards at Muhimbili University of Health and Allied Sciences and the Harvard School of Public Health and study data were reviewed by a Data Safety Monitoring Board twice annually. At the enrollment visit during pregnancy, trained research nurses collected data on women’s socioeconomic and health status, educational level, obstetric history, date of last menstrual period, and anthropometry. One month after enrollment, research nurses obtained a blood sample to measure maternal immunologic and hematologic parameters. Immediately after delivery, trained research midwives measured birth weight to the nearest 50 g with a standard mechanical scale and infant length to the nearest 0.1 cm with a length board. Gestational age at birth was calculated from the date of the last menstrual period, obtained at the time of study enrollment. After randomization, caretakers were asked to return with the child to the study clinic for monthly research visits. During these visits, nurses interviewed caretakers about the child’s morbidity history, determined compliance with the study regimen by counting the unused supplies, and measured child anthropometry using standard techniques (27). They measured the child’s weight on a digital infant balance with 10-g precision (Tanita) and length with 1-mm precision using a rigid length board with a movable foot piece. The study physicians examined the child every 3 mo. HIV infection status was determined at 6 wk and 18 mo. The launch of the President’s Emergency Plan for AIDS Relief program in July 2005 allowed for prospective HIV testing as well as increased access to antiretroviral treatment (ART)13. Children who were HIV uninfected at 18 mo and still breastfed were tested again before they were discharged from the study after 24 mo of follow-up. The trial aimed to determine whether the daily oral administration of multivitamins to Tanzanian children born to HIV-infected women reduces the risks of child mortality and diarrheal morbidity as the primary aims and growth faltering as a secondary aim. We calculated age- and sex-specific Z-scores for the anthropometric indexes length for age (LAZ), weight for length (WLZ), and weight for age (WAZ) using the 2006 WHO growth standards and related software (28). The study outcome was the difference in attained LAZ, WLZ, and WAZ between treatment and control groups. Our secondary study outcome measures were incidence of stunting (LAZ < −2), wasting (WLZ < −2), and underweight (WAZ < −2) among those free of these conditions at baseline. Children and their caretakers had access to standard pre- and postnatal care, including nutritional counseling and support. Prenatal care included daily doses of ferrous sulfate (200 mg, equivalent to 60 mg ferrous Fe) and folic acid (0.25 mg) as well as malaria prophylaxis with sulfadoxine-pyrimethamine tablets (Fansidar; Roche Pharmaceuticals) at 20 and 30 wk of gestation. On the basis of earlier findings of the benefits of prenatal multivitamins among HIV-infected women who were not receiving ART (29, 30), women received supplements containing high doses of vitamins B-complex, C, and E during and after pregnancy. A subset of women (71 in the treatment and 67 in the control group; P = 0.72) had been enrolled in an efficacy trial comparing these vitamin dosages with those of the RDA (31). Women who started on ART were changed to multivitamin supplements containing RDA levels of these nutrients. As part of standard medical care, all children received immunizations, routine medical care for illnesses, and periodic large doses of vitamin A at 9, 15, and 21 mo of age. Children received cotrimoxazole prophylaxis until 6 mo of age; after that, only breastfeeding or HIV-infected children continued to receive cotrimoxazole. Mothers were counseled on the risks and benefits of breastfeeding. The provision of the study regimen was in line with the WHO recommendation on exclusive breastfeeding, which allows for the administration of oral rehydration salts, drops, or syrups in addition to breast milk (32). When the study was designed, routine medical care for pregnant women with HIV infection included malaria prophylaxis, diagnosis and treatment for sexually transmitted diseases and prophylaxis, and diagnosis and treatment of opportunistic infections. Antiretroviral medication to curb maternal-to-child transmission of HIV was limited to nevirapine prophylaxis (one dose given to the mother at the onset of labor and one dose given to the infant within 72 h of birth) (33). As the study progressed, the availability of ART substantially increased through the President’s Emergency Plan for AIDS Relief and other governmental and nongovernmental programs. Beginning in July 2005, women and children in the study were screened for ART eligibility and treated according to Tanzanian Ministry of Health guidelines (34). For adults, eligibility was based on: WHO stage IV HIV disease, or CD4 cell count <200 cells/mm3, or WHO stage III and CD4 <350 cells/mm3. Eligibility for children was defined as follows: for children <18 mo, CD4% <20 or Pediatric WHO Stage III, or any child ≥18 mo of age with Pediatric WHO Stage III or CD4% <15%. For adults, the standard first-line regimen was stavudine, lamivudine, and nevirapine; for children, it was zidovudine, lamivudine, and nevirapine. Alternative drug regimens were available for special circumstances. Maternal HIV-1 serostatus was determined by 2 sequential ELISAs using Murex HIV antigen/antibody (Abbott Murex) followed by the Enzygnost anti-HIV-1/2 Plus (Dade Behring); discordant results were resolved by a Western-blot test (Bio-Rad Laboratories). Children <18 mo were tested for HIV infection using the Amplicor HIV-1 DNA assay version 1.5 (Roche Molecular Systems) and older children using HIV ELISAs. Hemoglobin concentrations were measured using an AcT5 Diff AL hematology analyzer (Beckman Coulter) and T-cell subsets using the FACSCalibur system (Becton-Dickinson). We used intent-to-treat analyses to estimate treatment effects. We fitted mean LAZ, WLZ, and WAZ curves using mixed effects models with restricted cubic splines and placed knots at 3- mo intervals after randomization (35). An automatic knot selection procedure was employed using P < 0.05 to determine a parsimonious model. To improve model fit for WLZ, an additional knot at age 6 wk was included. The variables included in each outcome model were the treatment group, linear and spline terms for time (in wk), and interaction terms between the treatment group and time. We determined the overall significance of the treatment during the 98-wk follow-up period by testing a model with main effects for linear and nonlinear terms for time against one with additional interaction terms between treatment group and time. We estimated the treatment effect as the difference in attained LAZ, WLZ, and WAZ scores between the multivitamin and placebo groups every 3 mo and from 6 to 104 wk. Because antiretroviral therapy in line with the latest recommendations can reduce mother-to-child transmission to <5% in breastfeeding populations (36), we analyzed the multivitamin effect over time among the subgroup of children who were HIV uninfected at baseline. Results were similar among children remaining HIV uninfected during follow-up and are therefore not shown. We used Cox proportional hazard models (37) with the exact method for ties (38) to investigate the treatment effects on incidence of stunting, wasting, and underweight. We set extreme values for LAZ (< −6 or >6), WLZ (< −5 or >5), and WAZ (< −6 or >5) to missing as recommended (28). We compared compliance with the study regimen across treatment groups with the Wilcoxon rank-sum test. All P values reported are 2-sided and significance was defined as P < 0.05. No adjustments for multiple comparisons were performed. Statistical analyses were carried out by using SAS system version 9.2 (SAS Institute).