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Background: Previous research indicates that young children in low-income countries (LICs) generally consume greater amounts of protein than published estimates of protein requirements, but this research did not account for protein quality based on the mix of amino acids and the digestibility of ingested protein.Objective: Our objective was to estimate the prevalence of inadequate protein and amino acid intake by young children in LICs, accounting for protein quality.Methods: Seven data sets with information on dietary intake for children (6-35 mo of age) from 6 LICs (Peru, Guatemala, Ecuador, Bangladesh, Uganda, and Zambia) were reanalyzed to estimate protein and amino acid intake and assess adequacy. The protein digestibility-corrected amino acid score of each child's diet was calculated and multiplied by the original (crude) protein intake to obtain an estimate of available protein intake. Distributions of usual intake were obtained to estimate the prevalence of inadequate protein and amino acid intake for each cohort according to Estimated Average Requirements.Results: The prevalence of inadequate protein intake was highest in breastfeeding children aged 6-8 mo: 24% of Bangladeshi and 16% of Peruvian children. With the exception of Bangladesh, the prevalence of inadequate available protein intake decreased by age 9-12 mo and was very low in all sites (0-2%) after 12 mo of age. Inadequate protein intake in children <12 mo of age was due primarily to low energy intake from complementary foods, not inadequate protein density.Conclusions: Overall, most children consumed protein amounts greater than requirements, except for the younger breastfeeding children, who were consuming low amounts of complementary foods. These findings reinforce previous evidence that dietary protein is not generally limiting for children in LICs compared with estimated requirements for healthy children, even after accounting for protein quality. However, unmeasured effects of infection and intestinal dysfunction on the children's protein requirements could modify this conclusion. [ABSTRACT FROM AUTHOR]

Measurement of fasting plasma zinc (PZn) concentration (cone) is not feasible for young children in community studies. We assessed the effects of time since last meal and hour of day on morning PZn concs of young children in trials in Peru and Ecuador. Peruvian children (n=297) were initially 6-8 mos of age; PZn concs were measured before and 6 mos after providing daily placebo or 3 mg/d supplemental zinc in either syrup or fortified porridge. Ecuadorian children (n=646) were initially 12-30 mos; only pre-intervention data are analyzed. In the Peru study, children either were allowed to breastfeed 1.5 hrs prior to blood sampling or the time of the last feed was recorded. In both studies the time of blood sampling was noted. In Peru, PZn cones were positively correlated with the number of hrs since the previous meal (r=0.22, p<0.0001). In both studies PZn cones were inversely correlated with time of day (Peru: r = -0.24; Ecuador: r = -0.18, p<0.0001). For the Peru study, a repeated measures ANOVA controlling for treatment group, Creactive protein, reported illness, and SES revealed that for each hr later in the morning that blood samples were collected, PZn cones decreased by 1.9 µg/dL; for each hr after meal consumption cones increased by 1.0 µg/dL. The effect of time of day was similar in the Ecuador study. These factors should be controlled to reduce variability and minimize confounding during assessments of population zinc status. [ABSTRACT FROM AUTHOR]

Background: It is not known whether superoxide dismutase (SOD) concentrations change with increasing altitude and decreasing ambient oxygen pressure. Methods: We conducted cross-sectional analyses of erythrocyte copperzinc SOD (ESOD) activity and other biochemical indicators in non-severely anemic 12-30 mo old children with mild-moderate stunting and living at different altitudes: 1) E1 Carmen, ∼300 meters (m), 2) Latacunga, ∼2800 m, and 3) Quito barrios, ∼3000+ m. Results: Site means were significantly different for ESOD (p=0.002), age, anthropometry, and plasma concentrations of copper, ceruloplasmin (Cp) and HDL, but not for plasma concentrations of zinc, ferritin or total cholesterol. None of these covariates had a significant effect on the differences in ESOD by site, and mean ESOD remained different by site (p<0.02) even after controlling for copper and Cp. Conclusions: ESOD concentrations were lower among children living at higher altitude, even after controlling for other indicators of copper status, suggesting a possible independent effect of altitude on ESOD concentration. [ABSTRACT FROM AUTHOR]

Background: Multiple studies have shown the benefits of zinc supplementation among young children in high-risk populations. However, the optimal dose and safe upper level of zinc have not been determined., Objectives: The objectives of this study were to measure the effects of different doses of supplemental zinc on the plasma zinc concentration, morbidity, and growth of young children; to detect any adverse effects of 10 mg supplemental Zn on markers of copper or iron status; and to determine whether any adverse effects are alleviated by providing copper with zinc., Design: This randomized, double-masked, community-based intervention trial was conducted in 631 Ecuadorian children who were 12-30 mo old at baseline and who had initial length-for-age z scores <-1.3. Children received 1 of 5 daily supplements for 6 mo: 3, 7, or 10 mg Zn as zinc sulfate, 10 mg Zn + 0.5 mg Cu as copper sulfate, or placebo., Results: The change in plasma zinc concentration from baseline was positively related to the zinc dose (P < 0.001). Zinc supplementation, including doses as low as 3 mg/d, reduced the incidence of diarrhea by 21-42% (P < 0.01). There were no other significant group-wise differences., Conclusions: Zinc supplementation with a dose as low as 3 mg/d increased plasma zinc concentrations and reduced diarrhea incidence in the study population. There were no observed adverse effects of 10 mg Zn/d on indicators of copper or iron status. The current tolerable upper level of zinc recommended by the Institute of Medicine should be reassessed for young children.