Iron and zinc supplementation improved iron and zinc status, but not physical growth, of apparently healthy, breast-fed infants in rural communities of northeast Thailand.

Iron deficiency is prevalent in children and infants worldwide. Zinc deficiency may be prevalent, but data are lacking. Both iron and zinc deficiency negatively affect growth and psychomotor development. Combined iron and zinc supplementation might be beneficial, but the potential interactions need to be verified. In a randomized, placebo-controlled trial using 2 x 2 factorial design, 609 Thai infants aged 4-6 mo were supplemented daily with 10 mg of iron and/or 10 mg of zinc for 6 mo to investigate effects and interactions on micronutrient status and growth. Iron supplementation alone increased hemoglobin and ferritin concentrations more than iron and zinc combined. Anemia prevalence was significantly lower in infants receiving only iron than in infants receiving iron and zinc combined. Baseline iron deficiency was very low, and iron deficiency anemia was almost nil. After supplementation, prevalence of iron deficiency and iron deficiency anemia were significantly higher in infants receiving placebo and zinc than in those receiving iron or iron and zinc. Serum zinc was higher in infants receiving zinc (16.7 +/- 5.2 micromol/L), iron and zinc (12.1 +/- 3.8 micromol/L) or iron alone (11.5 +/- 2.5 micromol/L) than in the placebo group (9.8 +/- 1.9 micromol/L). Iron and zinc interacted to affect iron and zinc status, but not hemoglobin. Iron supplementation had a small but significant effect on ponderal growth, whereas zinc supplementation did not. To conclude, in Thai infants, iron supplementation improved hemoglobin, iron status, and ponderal growth, whereas zinc supplementation improved zinc status. Overall, for infants, combined iron and zinc supplementation is preferable to iron or zinc supplementation alone.

A multimicronutrient-fortified seasoning powder enhances the hemoglobin, zinc, and iodine status of primary school children in North East Thailand: a randomized controlled trial of efficacy.

Anemia and co-existing deficiencies of zinc, iron, iodine, and vitamin A occur among children in many developing countries including NE Thailand, probably contributing to impairments in growth, immune competence, and cognition. Sustainable strategies are urgently required to combat these deficiencies. We assessed the efficacy of a micronutrient-fortified seasoning powder served with a school lunch on reducing anemia and improving the micronutrient status of rural NE Thai children. Children (n = 569) aged 5.5-13.4y from 10 schools were randomly assigned to receive a seasoning powder either unfortified or fortified with zinc (5 mg), iron (5 mg), vitamin A (270 microg), and iodine (50 microg) (per serving) and incorporated into a school lunch prepared centrally and delivered 5 d/wk for 31 wk. Teachers monitored school lunch consumption. Baseline and final micronutrient status, hemoglobinopathies, and infection or inflammation were assessed from blood and urine samples. For the primary outcome, anemia (based on hemoglobin), no intervention effect was apparent (odds ratio: 1.02 95% CI: 0.69, 1.51) after adjustment for design strata. The odds of zinc (based on serum zinc) and urinary iodine deficiency in the fortified group were 0.63 (0.42, 0.94) and 0.52 (0.38, 0.71) times those in the unfortified group, respectively. Fortification had no effect on serum retinol (0.61: 0.25,1.51), ferritin (1.12: 0.43, 2.96), or mean red cell volume (1.16: 0.82, 1.64). Therefore, a micronutrient-fortified seasoning powder is a promising vehicle for improving zinc, iodine, and hemoglobin status, and its potential for incorporation into lunch programs in day care centers and schools in NE Thailand warrants investigation.