Zinc and iron nutrition in Chilean children fed fortified milk provided by the Complementary National Food Program

Abstract

Objective: Chilean infants are at risk for isolated zinc and iron deficiencies because of a low consumption of animal products in low socioeconomic sectors. In 1999, the National Complementary Food Program of Chile manufactured a new milk (2 kg of powdered milk/mo) fortified with iron (Fe; 10 mg/L), zinc (Zn; 5 mg/L), and copper (0.5 mg/L) to be provided to infants until age 18 mo and to pregnant women. We analyzed the nutrition status of zinc and iron at age 18 mo in infants who consumed the fortified cow's milk.

Methods: Forty-two healthy male children with normal growth and from lower socioeconomic groups were studied. A nutrition survey was conducted; blood and hair samples for Zn in plasma and hair, hemoglobin, hematocrit, and serum ferritin were obtained.

Results: Mean intakes were: energy, 106 +/- 27 kcal. kg(-1). d(-1); protein, 3.8 +/- 1.1 g. kg(-1). d(-1); Zn, 5.2 +/- 1.9 g/d (0.98 mg Zn/MJ; 68% of World Health Organization recommendations); Fe, 11.2 +/- 5.5 mg/d; and dietary fiber, 9.8 +/- 3.9 g/d. Plasma Zn in 54.8% of children was no greater than 12.3 microM/L; 36% had hair Zn level no greater than 1.23 microM/g and 39% had serum ferritin levels no greater than 10 microg/dL (12% were anemic). Hair Zn was correlated to socioeconomic level (Spearman's rank correlation, r = -0.53; P < 0.001) and plasma Zn was correlated to the z weight/length (r = 0.47; P < 0.05), subscapular skinfold (r = 0.46; P < 0.05), and Zn intake (r = 0.46; P < 0.05).

Conclusions: The fortified powdered cow's milk provided to infants until age 18 mo by the Complementary Food Program in Chile favorably affects the Fe status of these children, but possibly not the Zn nutrition; we suggest re-evaluation of the levels of Zn fortification.