Plasma zinc concentration, body composition and physical activity in obese preschool children.

Zinc (Zn) deficiency and obesity can be observed together in some developing countries. Zn deficiency may enhance fat deposition and decrease lean mass accrual, which in turn, appears to influence physical activity (PA), although this has not yet been evaluated in obese children. The objective of the study was to find out the association between measurements of plasma Zn and serum leptin, body composition, and PA in Chilean obese preschool children. Seventy-two 18- to 36-month-old obese children [weight-for-length/height z score (WHZ) > 2.0 SD], belonging to low socioeconomic communities, participated in the study. Plasma Zn, serum leptin, weight, waist circumference, height, total body water (TBW) assessed by deuterium isotopic dilution technique and daily activity, measured by registering 48 h with an accelerometer, were evaluated. We found 82% of children with WHZ > 3 SD. The geometric mean Zn intake was 6.2 +/- 2.5 mg/day. The mean plasma Zn was 91.8 +/- 11.4 microg/dL, with 10% of the children having levels <80 microg/dL. No correlation was found between plasma Zn concentrations and either weight, WHZ, or waist circumference. Serum leptin was lower in males than in females (2.9 +/- 2.8 vs 6.8 +/- 5.0 ng/mL, respectively; p < 0.001). TBW was different between males and females (56.2 +/- 5.4 vs 52.8 +/- 4.3% body weight, respectively; p = 0.004), but no significant association was found between TBW and plasma Zn. Moderate + intense PA, (as percentage of wake time), was greater in males than in females (6.3 +/- 3.1% vs 3.4 +/- 2.3%, respectively; p < 0.001), but it was not significantly correlated to plasma Zn. In conclusion, plasma Zn was not associated with body composition as assessed by TBW, serum leptin, or with the magnitude of physical activity in Chilean overweight preschool children.

Copper deficiency impairs growth of infants recovering from malnutrition.

To evaluate the effect of copper deficiency on growth in humans we performed a prospective case-control study in 11 infants identified as Cu deficient based on low plasma Cu (less than 70 micrograms/dL [11.0 mumol/L]) and low ceruloplasmin (less than 200 mg/L). Growth was evaluated with anthropometric indices 1 mo before and 1 mo after onset of Cu supplementation of 80 micrograms.kg-1.d-1. Plasma Cu and ceruloplasmin rose significantly after 1 mo of supplementation. Weight-for-age and weight-for-length indices increased significantly after supplementation only in the Cu-deficient group. Daily energy intake was significantly higher in the Cu-deficient group after supplementation than it was in the control group. Daily weight gain after supplementation increased significantly in the Cu-deficient group and the value for daily weight gain after supplementation was significantly higher than that of the control group for the equivalent amount of time. Cu supplementation improves the growth of Cu-deficient infants recovering from malnutrition.

PIP: To evaluate the effect of copper deficiency on growth in humans a prospective case-control study was performed in Chile on a group of 11 infants identified as Cu deficient based on low plasma Cu (70 mcg/dL (11.0 mcmol/L) and low ceruloplasmin (200 mg/L). Growth was evaluated with anthropometric indices 1 month before and 1 month after onset of Cu supplementation of 80 mcg x 1/kg x 1/d. Plasma Cu and ceruloplasmin rose significantly after 1 month of supplementation. Weight-for-age and weight-for-length indices increased significantly after supplementation only in the Cu-deficient group. Daily energy intake was significantly higher in the Cu-deficient group after supplementation than it was in the control group. Daily weight gain after supplementation increased significantly in the Cu-deficient group and the value for daily weight gain after supplementation was significantly higher than that of the control group for the equivalent amount of time. Cu supplementation improves the growth of Cu-deficient infants recovering from malnutrition.

Oral copper supplementation: effect on copper and zinc balance during acute gastroenteritis in infants.

To evaluate the effect of copper supplementation during recovery from acute diarrhea, we randomly assigned 14 hospitalized infants to receive either 80 micrograms copper sulfate.kg body wt-1.d-1 or a placebo. Metabolic balance and plasma copper and zinc concentrations were measured before randomization (period 1) and 6 d after admission (period 2). Fifteen control subjects were studied after respiratory illness. Fecal copper was not affected by supplementation; fecal zinc during period 2 rose significantly only in the copper-supplemented group. Copper retention was significantly higher in the supplemented infants; plasma concentrations increased for period 2 but were similar to those in the placebo group. Zinc concentrations improved over time in both groups but zinc retention was higher in the placebo group for period 2. A significant interference by copper supplementation on zinc absorption was noted. Copper supplementation during the early phase of recovery from diarrhea is not recommended.

Fat intake during childhood: metabolic responses and effects on growth.

Lipids are considered the most important energy source in the infant diet and are necessary for normal growth and physical activity. Human milk, in which most of the energy is present as fat, provides a relatively high cholesterol intake. Formula provides a much lower cholesterol intake. Infants fed human milk have higher total and LDL-cholesterol concentrations in plasma than do formula-fed infants (P: < 0.05), whereas plasma HDL- and LDL-cholesterol concentrations are lower in formula-fed infants if a formula high in linoleate is fed (P: < 0.05). Infants adapt to the high cholesterol content of human milk through a decrease in cholesterol synthesis; in contrast, the addition of cholesterol to formula does not suppress synthesis. Measurements of serum lipoproteins and LDL-receptor activity suggest that it is the fatty acid content, rather than the cholesterol content, of the diet that regulates cholesterol homeostasis. We studied the effect of total energy, source of energy, and fat on growth indexes of children <6 y of age in Latin America with use of food balance data. With respect to availability of animal fat, a negative relation was evident for being underweight (percentage weight-for-age <2 SDs of the World Health Organization-National Center for Health Statistics standards) and for having a low birth weight; the latter was also negatively related to energy. Wasting (percentage weight-for-height <2 SDs) was not related to dietary factors. These results suggest that diets that provide <22% of energy from fat and that are low in animal fats may restrict growth. The coexistence of early stunting with adult obesity in Latin America creates a dilemma for public nutrition intervention programs.

Controlled trial of zinc supplementation during recovery from malnutrition: effects on growth and immune function.

To evaluate the effect of zinc on growth and immune function, 32 marasmic infants were selected on admission to the nutrition recovery center; 16 received 2 mg/kg daily of elemental zinc supplement as acetate and the remaining received a placebo. Immunity was assessed by skin-test response, T-cell blastic proliferation immunoglobulins, and infectious morbidity. Weight-for-length gain for initial 60 days in Zn-supplemented group was 9% of standard vs 3% for placebo (p less than 0.05). Energy intake was similar in both groups. Incidence of infections, especially pyoderma, was significantly higher in placebo group: 10 of 16 vs 3 of 16 in the supplemented group (p less than 0.025). Plasma Zn was correlated with number of febrile days in the prospective month (r = -0.66, p less than 0.05). The percent anergic infants decreased and serum IgA increased significantly only in Zn-supplemented group. Zinc supplementation has significant effects on weight gain and host defense mechanisms despite normal plasma levels. Zinc supplementation is recommended for optimal recovery from marasmus.

A 14-mo zinc-supplementation trial in apparently healthy Chilean preschool children.

Apparently healthy preschool children (46 boys, 52 girls) aged 27-50 mo from low socioeconomic conditions who attended daycare centers in Santiago participated in a 14-mo long double-blind zinc supplementation trial. Unlike most previous studies, no additional inclusion criteria such as short stature or slow growth rate were considered. Subjects were pair matched according to sex and age and randomly assigned to two experimental groups: the supplemented group, which received 10 mg Zn/d, and the placebo group. Selected anthropometric, clinical, dietary, biochemical, and functional indexes were determined at the beginning of the study and after 6 and 14 mo of intervention. Actual dietary zinc intake was 66% of the recommended dietary allowance. Height gain after 14 mo was on average 0.5 cm higher in the supplemented group (P = 0.10). The response, however, was different between sexes. Boys from the supplemented group gained 0.9 cm more than those in the placebo group (P = 0.045). No effect was seen in girls. Although no significant differences were observed in the rest of the variables studied, trends (0.05 < P < 0.10) in the supplemented group compared with the placebo group for increased midarm muscle area in boys, improved response to tuberculin, and reduced rates of parasite reinfestation were noted. We conclude that in preschool children of low socioeconomic status, zinc is a limiting factor in the expression of growth potential.

Controlled trial of copper supplementation during the recovery from marasmus.

To evaluate copper nutritional status and the effect of a Cu supplement during recuperation, 27 marasmic infants were selected on admission to the nutrition recovery center at the Instituto de Nutrición y Tecnología de los Alimentos. Thirteen infants received 80 micrograms/kg/day of copper supplement as sulphate and the remaining a placebo. They were paired by birth weight, age, and sex. Anthropometric indices, complete blood count, ceruloplasmin, and Cu were measured on admission and at monthly intervals. Superoxide dismutase activity was measured in hypocupremic infants and was found to be low. The mean +/- SE Cu levels on admission were 127 +/- 10 micrograms/dl for the supplemented group and 137 +/- 10 micrograms/dl for the control. We found an increase in plasma Cu to 159 and 162 micrograms/dl on days 30 and 60 in the supplement group, and a significant decrease after day 30 in the placebo group. The ceruloplasmin levels followed this trend. Hypocupremia was found in 30% of the placebo group and none in the supplement group. The placebo group had a significantly higher prevalence of severe lower respiratory infections. It is concluded that a significant proportion of marasmic infants fed a milk-based diet present, during recovery, biochemical evidence of Cu deficiency. Supplementation with Cu is suggested.

Trace minerals in human growth and development.

Trace mineral deficiencies may affect several biological functions in humans, including physical growth, psychomotor development and immunity. We have reviewed the mechanisms whereby several trace mineral deficiencies may affect these biological functions at different ages (fetal life, infancy, childhood and adolescence), as well as the evidence supporting this association. We describe the effects of zinc deficiency on the hormonal regulation of growth and sexual development in both humans and animal models. We provide data regarding the effects of iron deficiency on growth and psychomotor development. We mention the effects of copper, manganese, selenium and iodine deficiencies on growth and development. We conclude that iron deficiency may affect psychomotor development, but does not appear to affect growth. Zinc deficiency may cause growth retardation and psychomotor delay.

Trace minerals in human growth and development.

Trace mineral deficiencies may affect several biological functions in humans, including physical growth, psychomotor development and immunity. We have reviewed the mechanisms whereby several trace mineral deficiencies may affect these biological functions at different ages (fetal life, infancy, childhood and adolescence), as well as the evidence supporting this association. We describe the effects of zinc deficiency on the hormonal regulation of growth and sexual development in both humans and animal models. We provide data regarding the effects of iron deficiency on growth and psychomotor development. We mention the effects of copper, manganese, selenium and iodine deficiencies on growth and development. We conclude that iron deficiency may affect psychomotor development, but does not appear to affect growth. Zinc deficiency may cause growth retardation and psychomotor delay.

Controlled study of early postoperative parenteral nutrition in children.

BACKGROUND/PURPOSE: Nutritional support of surgical patients has improved in recent years because of the possibility of modulating catabolism and anabolism, thus enhancing the immune response and repair processes. The objective of this study was to evaluate metabolic effects of early parenteral nutrition (PN) after major surgery. METHODS: The authors studied 63 children aged 4 to 14 years with diffuse peritonitis caused by perforated-suppurative appendicitis. They were assigned randomly to a study group (SG, n = 31), which received PN for 5 days, starting 24 to 48 hours after surgery or to a control group (CG, n = 32), that received standard treatment (fluids). Weight, C-reactive protein (CRP), albumin, prealbumin, glycemia, nitrogen balance (NB), and insulinlike growth factor (IGF-I), were evaluated on postoperative days 1, 4, and 6. RESULTS: Early nutritional support was associated with a significant improvement in NB and IGF-I (Repeat measures analysis of variance IGF-I, P<.001 and NB P<.01). CONCLUSIONS: The authors conclude that early parenteral nutrition has a positive effect on the anabolic response as shown by improved NB and higher IGF-I levels in pediatric patients after major surgery.

[Nutritional status and clinical evolution of hospitalized Chilean infants with infection by respiratory syncytial virus (RSV)]. / Estado nutricional y evolución clínica de lactantes chilenos hospitalizados con infección por virus respiratorio sincicial (VRS).

Respiratory syncycial virus (RSV) is the first cause of acute lower respiratory tract infection in Chilean infants. A significant impact of nutrition on clinical course of these infections has been described. In order to analyze the association between nutritional status (NS) and clinical course of infants hospitalized with acute lower respiratory tract infection due to RSV, 130 infants (mean age 5.8 +/- 4.9 m) without chronic diseases, admitted to hospital with confirmed RSV infection, were studied. Clinical course of disease was assessed (hospitalization days and days with oxygen therapy) according to nutritional status on admission (weight/length (W/L), ratio, arm muscle area, lymphocyte count and albumin), antropometrics changes, and hospital dietary intake. On admission prevalence of malnutrition by W/L (z score) was 1%, 14% overweight and 8% were obese. Median value of hospitalization days was 5 d (2-29 d) and days receiving oxygen was 3 d (0-19 d). Longer admission were observed in fasted patients than in those who were fed everyday (Wilcoxon and Log-rank test, 8 d vs 5 d; P < 0.01). Obese children (Wilcoxon and Log-rank test, 5 d vs. 3d in normal patients; P < 0.05), and patients not fed enterally (Wilcoxon and Log-rank test, 7 d vs. 3 d; P < 0.01) required oxygen for longer time. Fasting and severity of illness (Tal score) were correlated variables (X2 0.001). The multivariate analysis showed an association of Tal score and NS on admission, with days receiving oxygen therapy. We conclude that obesity is a risk factor for worse clinical course of acute lower respiratory tract infection in Chilean infants with RSV infection and without chronic disease.

[Mineral balance during nutritional recuperation of infants with protein deficiency]. / Balance de minerales durante la recuperación nutricional en lactantes con desnutrición energético-proteica.

Mineral requirements of normal infants change according to growth velocity. They are directly associated to needs for obtaining an adequate composition of new tissue, assure an optimal bone mineralization and for maintaining normal plasma mineral levels. Nutritional rehabilitation of malnourished infants determines increased mineral requirements, which may be not satisfied with usual infant formulas. We studied mineral retention (Ca, P, Mg, Zn and Cu) during nutritional recovery of 9 malnourished male infants (age: 2-7 mo; weight/age < 70%), fed two formulas, both with 85 Kcal/dL (356 KJoule/dL): the first based on whole cow's milk (LP) and the second on a modified cow's milk containing mineral recommendations for normal infants (LPM); balances were compared to normal for age and for length. Infants received each formula for 6 days, with the last 3 days on a metabolic balance Ca, Mg, and P showed high intakes and very low urinary excretions, calcium retention (68.5 +/- 22.7 and 61.4 +/- 16.7 mg/kg/d, for LP and LPM, respectively) were 3 times over normal mean for age (130 mg/d) and 2.5 times over the normal for length (155 mg/d). Mg retention (7.4 +/- 2.0 and 3.4 +/- 1.2 mg/kg/d)), for LP and LPM) were higher than normal for age (2.7 mg/d) or length (3.3 mg/d) and also those of P (LP: 74.8 +/- 7.1; LPM: 52.2 +/- 9.3 mg/kg/d), compared to a mean of 66 mg/d for the same age, or 79 mg/d for length. Zn retentions were comparable with both formulas (LP: 0.14 +/- 0.07 vs LPM: 0.18 +/- 0.06 mg/kg/d) and over normal requirements for age (0.3 mg/d) or length (0.5 mg/d). Copper retentions were significantly lower with LP than LPM (13.8 +/- 14.0 vs 40.0 +/- 13.2 micrograms/kg/d; p < 0.01), due to low intake with LP. We conclude that a high mineral retention is observed in infants recovering from malnutrition, when they are fed formulas with mineral content over its normal recommendations.

[Plasma zinc and copper in infants with protein-calorie malnutrition]. / Zinc y cobre plasmáticos en lactantes con desnutrición proteínico-energética.

Forty-five marasmic infants were studied for plasma zinc and copper levels. They were selected from those children admitted to a nutritional recovery center. The mean plasma zinc level was 92.4 +/- 24 micrograms/dl (mean +/- SD); 7% of the infants had low zinc values as defined by zinc less than 70 micrograms/dl. Median copper was 90 micrograms/dl (range 27-172) and 49% of the children had copper levels below 90 micrograms/dl (established as our normal limit). Birth weight, breast feeding and prior hospitalization for acute diarrhea with dehydration were studied as antecedents related to low Cu and Zn. Children with prior diagnosis of acute diarrhea and hospitalization had lower copper levels than those sent from primary care centers. Breast feeding was associated with higher Cu levels. No relationship was found between zinc levels and those antecedents, but differences were found in regard to the degree of malnutrition, season of the year and Zn status. In this investigation no Zn deficiency was found in marasmus cases. Hypocupremia, however, is a very significant problem in marasmic infants, especially when associated with early weaning and the presence of previous hospitalization for acute diarrhea.

[Risk factors of bloodstream infections associated with parenteral nutrition in pediatric patients]. / Factores de riesgo de infecciones del tracto sanguíneo asociadas a alimentación parenteral en pacientes pediátricos.

INTRODUCTION: One of the complications of parenteral nutrition (PN) is bloodstream infection (BSI) associated with catheter, unknown the most important risk factors in our country. OBJECTIVE: To determine risk factors of BSI associated with PN in pediatric patients in public hospitals of Santiago, Chile. PATIENTS AND METHODS: In two public hospitals all newborns and children receiving PN were analyzed retrospectively, from January 2002 to December 2005. The study group (SG) was formed by all those with blood cultures (+) during the administration of PN. We selected two controls for each case, children with PN and blood cultures (-) (control group, CG). We used parametric, nonparametric and logistic regression to analyze data. RESULTS: There were 58 cases and 130 controls. Children of the SG received PN for longer days than CG: 24 (7-934) vs. 10 days (7-152) (p < 0.001), presented a higher rate of malnutrition (44.4% vs. 31%, chi2, p < 0.05) and received more frequently PN by central venous catheter than peripheral catheter (GE: 60.3% and 6.9% vs. GC: 40.9% and 16.9% respectively, chi2, p < 0.01), without differences between newborns and older children. The stepwise logistic regression showed that the only significant variable was the duration of PN in weeks (OR: 1.55,95% CI 1.28 to 1.9; p < 0,05). CONCLUSIONS: The blood stream infections associated with parenteral nutrition in children in public hospitals of Santiago, are associated with longer duration of parenteral nutrition and in less degree to the child's nutritional compromise.

Trace mineral balance during acute diarrhea in infants.

To evaluate the magnitude of copper and zinc losses during acute diarrhea requiring hospitalization, we studied 14 infants, 3 to 14 months of age, and compared them with a control group of 15 infants of similar age, birth weight, and nutritional status. Metabolic balance studies were conducted in the study group during an initial 48 hours (period 1) and on days 6 and 7 after admission (period 2). The control group was studied after recovery from respiratory disease. Copper and zinc content of feces, urine, and food samples was measured by atomic absorption spectrophotometry. Mean (+/- SD) fecal losses were higher for period 1 in the diarrhea group than in control subjects: Cu 55.7 +/- 21.2 versus 28.8 +/- 6.7 micrograms/kg/body weight/day (p less than 0.01); Zn 159.4 +/- 59.9 versus 47.4 +/- 6.4 micrograms/kg/day (p less than 0.0001). For period 2, Zn losses were similar in both groups, but Cu balance remained negative only in the study group. Retention of Zn for the study group went from -21.2 +/- 46.7 in period 1 to 204.5 +/- 103.0 micrograms/kg/day in period 2 (p less than 0.0001), and fecal weight decreased from 70.5 +/- 20.6 in period 1 to 36.8 +/- 20.0 gm/kg/day in period 2. Fecal weight and fecal losses were correlated: r = 0.71 (p less than 0.01) for Cu and r = 0.81 (p less than 0.001) for Zn. Plasma mean Cu and Zn levels were low in period 1 but rose in period 2, especially for Zn. A negative correlation was found between fecal Zn losses and plasma Zn: r = 0.74 (p less than 0.001). We conclude that acute diarrhea leads to Cu and Zn depletion and that plasma levels and Cu balance remain abnormal a week after admission.

Red cell superoxide dismutase activity as an index of human copper nutrition.

Red cell superoxide dismutase (SOD) activity was evaluated as a biochemical index of copper nutrition in a double-blind study of 17 infants recovering from malnutrition and receiving marginal copper intakes. Children were paired on admission by sex, birth weight, nutritional status and antecedents of diarrhea and breast feeding. Nine served as controls receiving a copper sulfate supplement (80 micrograms/kg daily for 120 d; eight received a placebo and were supplemented only if plasma copper levels dropped below 90 micrograms/dl or on d 90 for at least 30 d. After copper supplementation there was a significant rise (paired t-test; P less than 0.05) in plasma copper (96 vs. 165 micrograms/dl); ceruloplasmin (33 vs. 50 mg/dl) and SOD (1073 vs. 1371 U/g Hb). After supplementation these values were similar to those of the controls. SOD was correlated with plasma copper (r = 0.78; P less than 0.001) and not with weight-for-age or weight-for-length. Addition of copper in vitro did not modify the SOD activity. Red cell SOD is a good marker of copper nutrition in humans and correlates well with plasma copper.

Zinc and copper in hair and plasma of children with chronic diarrhea.

Zinc and copper status was evaluated in nineteen children with chronic diarrhea. An intestinal biopsy suggested that eight of these patients had celiac disease and eleven suffered chronic diarrhea without malabsorption and had normal villi or minimal changes. They were studied for malabsorption and compared with two control groups consisting of nineteen healthy and eleven malnourished children. Plasma zinc was depressed in the celiac disease group when compared with the normal children, but was similar to that of the malnourished children. Hair zinc was also depressed for the chronic diarrhea groups (23.2 +/- 15.2 and 34.4 +/- 21.9 micrograms/g for those with or without malabsorption respectively, vs. 97.9 +/- 15.2 for the healthy group). Plasma and hair copper values were diminished in both groups with chronic diarrhea. A significant correlation was found between plasma carotene levels after oral carotene overload, and both plasma zinc and hair copper values (r = 0.62, p less than 0.01 and r = 0.56, p less than 0.05, respectively). There was also a significant correlation between plasma zinc and plasma protein (r = 0.54, p less than 0.05). Hair determinations seem to be more sensitive than plasma values to changes in zinc or copper status in chronic diarrhea. Chronic diarrhea in children is associated with lower levels of zinc and copper, especially when accompanied by malabsorption.

Zinc supplementation and growth of infants born small for gestational age.

To analyze the effect of zinc supplementation on postnatal growth of infants born small for gestational age, we selected 68 infants at birth and followed them monthly for 6 months. They were randomly assigned to a supplemented group (group S, n = 35) receiving 3 mg of Zn (acetate) per day, or to a placebo (group P, n = 33), in a double-blind study. Weight increments in group S were significantly higher than those in group P at 2 months (p < 0.003); z scores showed catch-up growth only in group S. Length increments were also greater in group S than in group P, ending at 6 months were 64.9 +/- 1.8 versus 63.4 +/- 3.5 cm (mean +/- SD; p < 0.01); changes in z scores for 6 months were -1.28 to -0.66 in group S and -1.43 to -1.47 in group P (p < 0.001). Weight-for-length improved similarly in both groups (z score, -2.2 to +0.2). The increase in weight-for-age was higher in group S girls (p < 0.034), ending at 6 months with -0.13 +/- 0.59, versus -0.52 +/- 0.62 in group S boys, -1.15 +/- 0.49 in group P girls, and -1.05 +/- 0.80 in group P boys (+/- SD). More infants in group P received cow milk-based formula before 4 months because of inadequate weight increments. An additive effect on weight increase was observed between Zn supplementation (p < 0.02), exclusive breast-feeding after 4 months of age (p < 0.001), and gender (p < 0.02). Plasma and hair Zn values showed a downward trend, less marked in group S than in group P. We conclude that Chilean infants born small for gestational age have better weight and linear growth during the first 6 months of life if they receive Zn supplementation.

Zinc supplementation increases growth velocity of male children and adolescents with short stature.

We assessed the effect of zinc supplementation on growth velocity in 79 children and adolescents (48 males, 38 females) with idiopathic short stature. Their height-for-age was < 5th percentile (NCHS standards) and their weight-for-age was normal. Patients were assigned randomly to a supplemented group (S) to receive Zn 10 mg/day or to a placebo (P) group, according to gender and age, and were followed-up for 12 months using a double-blind design. Weight, height, armspan, length of lower segment and plasma and hair concentrations of Zn were measured at 0, 3, 6 and 12 months. On admission and at 6 months, energy, protein, dietary fiber and zinc intakes were similar for groups S and P; mean zinc intake was < 6.5 mg/day. No differences were found in plasma zinc, hair zinc, weight, armspan or lower segment increments. Pre-adolescent males in group S had a significantly greater increase in stature compared with group P (6.2 +/- 2.1 versus 4.5 +/- 1.2 cm/year p < 0.025); z score improved from -2.42 to -2.24 in group S and from -2.63 to -2.61 in group P. For adolescent males, the difference was also significant (8.3 +/- 1.5 versus 6.2 +/- 2.1 cm/year; p < 0.025). No differences were noted in females. In Chilean male schoolchildren and adolescents with idiopathic short stature, zinc supplementation increases growth velocity over a 12-month period.

Effect of zinc supplementation on development and growth of Chilean infants.

OBJECTIVE: To evaluate the effect of zinc supplementation on growth and development during infancy. DESIGN: We randomized 150 term neonates of low socioeconomic status to receive supplemental zinc 5 mg/d (SG) or a lactose placebo (PG); 112 completed a 1-year follow-up. All were breast-fed and given cow milk formula after weaning; solid foods and iron were added at 5 months. Anthropometry measured monthly, psychomotor development (PDI), mental development (MDI), and behavior including motor quality factor were assessed by Bayley Scales at 6 and 12 months. The groups were comparable in maternal characteristics, birth weight, home environment, and mother-infant interaction. RESULTS: No effects of zinc on weight, length, and weight for length at 12 months were found controlling for sex and breast-feeding. The mean PDI (SG: 84.5 +/- 11.5 vs PG: 87.6 +/- 9.9) and MDI (90.9 +/- 10.5 vs 88.9 +/- 9.1) were similar; however, 46 of 52 infants in the PG scored <100 in MDI vs 42 of 57 in the SG (P <.05). A smaller proportion of the SG, 2 of 57, scored low in motor quality factor at 6 months compared with the PG, 8 of 52 (P =.02). The mean at 12 months for the SG was 31.9 +/- 2.8 and for the PG 30.8 +/- 2.9 (P <.05); zinc supplementation entered the multiple regression at 12 months (P =.037). CONCLUSIONS: Zinc supplementation may have a beneficial effect on mental development and motor quality behavior of healthy term infants.