No abstract

This study attempted to define the possible contribution of zinc nutrition to immunocompetence and growth in severely malnourished infants. The effect of zinc supplementation was evaluated in marasmic infants during nutritional rehabilitation by using a controlled double-blind design in which 19 infants fed a zinc-fortified formula were compared with 20 infants fed the same non-supplemented formula. Evaluation of immunocompetence, growth, and zinc, copper, and iron status was performed on admission and at 30, 60, and 105 d of nutritional rehabilitation. Although energy intake was similar in both groups, the zinc-supplemented infants had significantly higher linear growth gain, and their immune function improved as demonstrated by conversion of their delayed hypersensitivity skin reactions, enhanced lymphoproliferative response to PHA, and increased salivary IgA concentrations. Thus, the use of a zinc-fortified formula during nutritional rehabilitation can prevent the development of zinc deficiency and improve growth and immune function.

The effects on pregnancy outcome and maternal iron status of powdered milk (PUR) and a milk-based fortified product (V-N) were compared in a group of underweight gravidas. These take-home products were distributed during regular prenatal visits. Women in the V-N group had greater weight gain (12.29 vs 11.31 kg, p less than 0.05) and mean birth weights (3178 vs 3105 g, p less than 0.05) than those in the PUR group. Values for various indicators of maternal Fe status were also higher in the V-N group. Compared with self-selected noncompliers, similar in all control variables to compliers, children of women who consumed powdered milk or the milk-based fortified product had mean birth weights that were higher by 258 and 335 g, respectively. Data indicate a beneficial effect of the fortified product on both maternal nutritional status and fetal growth.

The bioavailability of iron added to different types of cows' milk formulas was studied using mono-isotopic and double-isotopic methods in 396 infants aged 5-18 mo. All the milk formulas were fortified with ferrous sulfate in concentrations varying between 10 and 19 mg elemental iron/liter. Iron absorption from low-fat milks and full-fat milks varied from 2.9 to 5.1%. A higher range of mean absorption, 5.9 to 11.3%, was observed in the same formulas with the addition of ascorbic acid at concentrations of 100 mg/l or higher (up to 800 mg/l), demonstrating its enhancing effect on iron absorption in fortified milks. The amount of milk fat, the addition of carbohydrates, or acidification did not seem to influence iron absorption.

The Chilean School Lunch program, which serves one million children nationwide, was supplied with three 10-g cookies fortified with 6% bovine hemoglobin concentrate, designed to provide 1 mg bioavailable iron per day. A survey of 1000 children was performed after 3 y. Significant differences in hemoglobin concentrations were found in the children from the fortified vs the nonfortified province (P < 0.01). Low serum ferritin values were also significantly more prevalent in the nonfortified group. The effect was evident despite the very low prevalence of anemia in both the fortified and the unfortified school groups. Heme-iron-fortified cookies are a feasible and effective way to improve the iron status of school-age children. In regions of high prevalence of iron-deficiency anemia, the effect of a heme-fortified cookie program should be even more important.

Phagocytosis and bactericidal capacity of neutrophils were measured in 10 iron-deficient infants age 6-23 mo. All infants had hemoglobins less than 11 mg/dL with low saturation of transferrin and serum ferritin but were otherwise in good health. Neutrophil function and iron status were assessed at 0, 3-5, 15, 30, and 90 days of oral iron therapy. Phagocytosis was unaffected in iron deficiency and remained unchanged during therapy. Bactericidal capacity was severely impaired prior to treatment. After 3-5 days of ferrous sulfate administration, there was no significant improvement. At day 15 it returned to normal ranges and remained so at days 30 and 90. The sequence of events suggests that iron does not have a direct effect upon circulating neutrophils but, rather, that it is required during the development of neutrophils in the bone marrow.

In a longitudinal study from age 3 to 15 mo, 276 term, healthy, spontaneously weaned infants received a full-fat acidified milk fortified with 15 mg of elemental Fe as ferrous sulfate and 100 mg of ascorbic acid/100 g of powder and 278 control infants received milk without additives. At ages 9 and 15 mo significant differences were encountered in all measures of Fe nutriture in favor of the fortified group (p less than 0.001). Anemia (Hg less than 110 g/L) was present in 25.7% of unfortified infants compared with only 2.5% in those fortified at age 15 mo. Saturation of transferrin less than 9% was present in 33.8% and serum ferritin less than 10 micrograms/L in 39.1% of the nonfortified infants. The figures for the fortified group were 7 and 8.5% respectively. The efficiency of the fortified acidified milk in eradicating Fe deficiency in the infants while discouraging use by other family members make this milk a useful targeted product in programs of supplementary food distribution in the underdeveloped world.

The availability and daily absorption of iron was determined by the extrinsic label method in typical lower middle to lower class diets consumed in regions of Argentina, Brazil, Chile, Mexico, Peru, and Venezuela. Differences in iron absorption from meals up to 7-fold, could be attributed to the varying contents of absorption enhancers, eg, in meat, and of inhibitors in tea, vegetables, and wheat or maize bread. The total iron available in the diets from four countries did not meet the physiological requirements for normal subjects but deficient subjects fulfilled their requirements absorbing from 1.0 to 2.1 mg/day. In five diets heme iron (6 to 24% of the total) provided 34 to 73% of the iron absorbed. These data suggest that such absorption and utilization studies may be used to correlate the prevalence of iron deficiency in a population with certain diets and to guide fortification programs.