Multiple micronutrient supplementation improves anemia, micronutrient nutrient status, and growth of Vietnamese infants: double-blind, randomized, placebo-controlled trial.

A randomized, double-blind, placebo-controlled trial was performed to assess the efficacy of different micronutrient supplementation regimes for improving micronutrient status, preventing anemia, and growth faltering of Vietnamese infants. A population-based sample of 306 infants aged 6-12 mo, split in 4 treatment groups, received daily multiple micronutrient (DMM), daily placebo (P), weekly multiple micronutrient (WMM), or daily iron (DI) supplements for 6 mo, 7 d/wk, under supervision. Weight and length were measured monthly, and anemia and plasma levels of ferritin, zinc, riboflavin, retinol, tocopherol, and homocysteine were determined before and after the supplementation. Z-scores for length-for-age and weight-for-age worsened significantly in all groups, but the length-for-age Z-score decreased significantly less in the DMM group (-0.32 +/- 0.05) than in the P and WMM groups (-0.49 +/- 0.05 and -0.51 +/- 0.05, respectively, P = 0.001). Hemoglobin levels increased significantly more in the DMM group [mean (95%CI): 16.4 g/L (12.4-20.4)] than in the P group [8.6 g/L (5.0-12.2), P = 0.04), with intermediate nonsignificant increases in the WMM [15.0 g/L (11.5-18.5)] and the DI [12.9 g/L (8.4-17.3)] groups. Ferritin changes were significantly greater in DMM (12.1 microg/L) and DI (9.5 microg/L) than in P (-14.7 microg/L) and WMM groups (-9.7 microg/L). Of the other micronutrients, only tocopherol showed a significantly greater level in the DMM group compared with P. Anemia still affected a quarter and zinc deficiency affected a third of infants although there was no iron deficiency after 6 mo of supplementation with DMM, suggesting that multiple factors are causing anemia and that the dose of zinc is too small.