Effects of zinc and multivitamin supplementation on hematologic status during infancy

OBJECTIVE: To determine the separate effects of zinc and multivitamin supplementation on infant hematologic status. METHODS: In a double-blind RCT, infants born to HIV-negative women (n=2400) in Dar es Salaam, Tanzania were randomized to daily oral supplementation with zinc (Zn), multivitamins (MV), Zn and MV, or placebo at age 6 wk. Hemoglobin concentration (Hb) and red cell indices were measured at baseline and ages 6, 12, and 18 mo. A subset of infants (n = 589) was examined for iron deficiency at 6 mo, defined as ferritin 8.3 mg/L. RESULTS: Infants treated with MV had higher mean Hb than those given placebo or Zn alone at 18 mo (9.9 vs. 9.6 g/dL, p = .0009). Infants treated with Zn had RR of 1.71 (95% CI 1.01 – 2.89) for iron deficiency at 6 mo, while those treated with MV had RR 0.52 (95% CI 0.30 – 0.90). In Cox models, MV were associated with a 28% reduction in risk of severe anemia (HR = 0.72 [95%CI 0.56 – 0.94]) and a 26% r...