Effects of zinc and multivitamin supplementation on hematologic status during infancy
At the time of publication, Kerri B. Gosselin was not yet affiliated with the University of Massachusetts Medical School.
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 < 12 μg/L or, where α-glycoprotein 蠅 1.0 g/L, serum transferrin receptor > 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% reduction in risk of severe microcytic anemia (HR = 0.74 [95% CI 0.56 – 0.96]) through age 18 mo. No effects of Zn on risk of anemia were seen.
CONCLUSIONS: MV were associated with reduced risk of both iron deficiency and severe microcytic anemia, while Zn was associated with increased risk of iron deficiency but no longer term increase in risk of anemia.
Funding: NICHD (R01 HD048969; K24HD058795); NIAAA (K23 AA020516); Bill and Melinda Gates Foundation (OPP1066203)