Exchangeable Zinc Pool Size at Birth in Pakistani Small for Gestational Age and Appropriate for Gestational Age Infants Do Not Differ But Are Lower Than in US Infants.

OBJECTIVES: Small for gestational age (SGA) infants are more susceptible to infectious morbidity and growth faltering compared to their appropriate for gestational age (AGA) counterparts. Zinc supplementation of SGA infants may be beneficial but the underlying susceptibility to zinc deficiency of SGA infants has not been examined. METHODS: In a community-based, observational, longitudinal study in a peri-urban settlement of Karachi, Pakistan, we compared the size of the exchangeable zinc pools (EZPs) in term SGA and AGA infants at birth and at 6 months of age, hypothesizing that the EZP would be lower in the SGA group. To measure EZP size, a zinc stable isotope was intravenously administered within 48 hours of birth (n = 17 and 22) at 6 months (n = 11 and 14) in SGA and AGA infants, respectively. Isotopic enrichment in urine was used to determine EZP. RESULTS: No significant difference was detected in the mean (±standard deviation) EZP between SGA and AGA infants at birth, with values of 9.8 ±â€Š3.5 and 10.1 ±â€Š4.1 mg/kg, respectively (P = 0.86), or at 6 months. Longitudinal EZP measurements demonstrated a significant decline in EZP relative to body weight in both groups at 6 months (P < 0.001). Mean EZP (adjusted for body weight) size at birth for the combined Pakistani groups was significantly lower than AGA infants at birth in the United States (P = 0.017). CONCLUSIONS: These results did not support a difference in zinc endowment between SGA and AGA Pakistani infants. They, however, do suggest lower in utero zinc transfer to the fetus in a setting where poor maternal nutritional status may confer a high susceptibility to postnatal zinc deficiency.

Zinc Absorption from Fortified Milk Powder in Adolescent Girls.

Zinc (Zn) is essential for development, growth, and reproduction. The Mexican government subsidizes micronutrient-fortified milk for risk groups, with positive effect on the targeted groups' plasma Zn level, inferring a good absorption is achieved although it has not being measured. The aim of this study was to determine the impact of micronutrient-fortified milk intake during 27 days on Zn absorption in adolescent girls from northwest Mexico. Therefore, Zn absorption was evaluated in 14 healthy adolescent girls (14.1 years old) with adequate plasma Zn levels, before and after 27 days of fortified Zn milk intake. Fractional Zn absorption (FZA) was calculated from urinary ratios of stable isotopic Zn tracers administered orally and intravenously on days 0 and 27, and total absorbed Zn (TZA) was calculated. At the beginning, Zn intake was 6.8 ± 0.85 mg/d (mean ± SE), and 50 % of the adolescent girls did not achieve their requirement (7.3 mg/d). Additionally, FZA was negatively correlated with Zn intake (r =-0.61, p = 0.02), while TZA (1.06 mg/d) was insufficient to cover the physiologic requirements of adolescent girls (3.02 mg/d). At the end of the intervention, all the girls reached the Zn intake recommendation and TZA, 3.09 mg/d, which was enough to meet the physiological requirement for 57 % of the adolescent girls. Therefore, the low Zn intake and the Zn status of adolescent girls were positively impacted by Zn-fortified milk intake and its good absorption rate.

Training traditional birth attendants on the WHO Essential Newborn Care reduces perinatal mortality.

OBJECTIVES: To evaluate the impact of birth attendant training using the World Health Organization Essential Newborn Care (ENC) course among traditional birth attendants, with a particular emphasis on the effect of acquisition of skills on perinatal outcomes. DESIGN: Population-based, prospective, interventional pre-post design study. SETTING: 11 rural clusters in Chimaltenango, Guatemala. POPULATION: Health care providers. METHODS: This study analyzed the effect of training and implementation of the ENC health care provider training course between September 2005 and December 2006. OUTCOME MEASURES: The primary outcome measure was the rate of death from all causes in the first seven days after birth in fetuses/infants ≥1500g. Secondary outcome measures were overall rate of stillbirth, rate of perinatal death, which included stillbirths plus neonatal deaths in the first seven days in fetuses/infants ≥1500g. RESULTS: Perinatal mortality decreased from 39.5/1000 pre-ENC to 26.4 post-ENC (RR 0.72; 95%CI 0.54-0.97). This reduction was attributable almost entirely to a decrease in the stillbirth rate of 21.4/1000 pre-Essential Newborn Care to 7.9/1000 post-ENC (RR 0.40; 95%CI 0.25-0.64). Seven-day neonatal mortality did not decrease (18.3/1000 to 18.6/1000; RR 1.05; 95%CI 0.70-1.57). CONCLUSION: Essential Newborn Care training reduced stillbirths in a population-based controlled study with deliveries conducted almost exclusively by traditional birth attendants. Scale-up of this intervention in other settings might help assess reproducibility and sustainability.

Bioavailability of zinc oxide added to corn tortilla is similar to that of zinc sulfate and is not affected by simultaneous addition of iron.

BACKGROUND: Corn tortilla is the staple food of Mexico and its fortification with zinc, iron, and other micronutrients is intended to reduce micronutrient deficiencies. However, no studies have been performed to determine the relative amount of zinc absorbed from the fortified product and whether zinc absorption is affected by the simultaneous addition of iron. OBJECTIVE: To compare zinc absorption from corn tortilla fortified with zinc oxide versus zinc sulfate and to determine the effect of simultaneous addition of two doses of iron on zinc bioavailability. METHODS: A randomized, double-blind, crossover design was carried out in two phases. In the first phase, 10 adult women received corn tortillas with either 20 mg/kg of zinc oxide added, 20 mg/kg of zinc sulfate added, or no zinc added. In the second phase, 10 adult women received corn tortilla with 20 mg/kg of zinc oxide added and either with no iron added or with iron added at one of two different levels. Zinc absorption was measured by the stable isotope method. RESULTS: The mean (+/- SEM) fractional zinc absorption from unfortified tortilla, tortilla fortified with zinc oxide, and tortilla fortified with zinc sulfate did not differ among treatments: 0.35 +/- 0.07, 0.36 +/- 0.05, and 0.37 +/- 0.07, respectively. The three treatment groups with 0, 30, and 60 mg/kg of added iron had similar fractional zinc absorption (0.32 +/- 0.04, 0.33 +/- 0.02, and 0.32 +/- 0.05, respectively) and similar amounts of zinc absorbed (4.8 +/- 0.7, 4.5 +/- 0.3, and 4.8 +/- 0.7 mg/day, respectively). CONCLUSIONS: Since zinc oxide is more stable and less expensive and was absorbed equally as well as zinc sulfate, we suggest its use for corn tortilla fortification. Simultaneous addition of zinc and iron to corn tortilla does not modify zinc bioavailability at iron doses of 30 and 60 mg/kg of corn flour.

High mortality rates for very low birth weight infants in developing countries despite training.

OBJECTIVE: The goal was to determine the effect of training in newborn care and resuscitation on 7-day (early) neonatal mortality rates for very low birth weight (VLBW) infants. The study was designed to test the hypothesis that these training programs would reduce neonatal mortality rates for VLBW infants. METHODS: Local instructors trained birth attendants from 96 rural communities in 6 developing countries in protocol and data collection, the World Health Organization Essential Newborn Care (ENC) course, and a modified version of the American Academy of Pediatrics Neonatal Resuscitation Program (NRP), by using a train-the-trainer model. To test the impact of ENC training, data on infants of 500 to 1499 g were collected by using a before/after, active baseline, controlled study design. A cluster-randomized, controlled trial design was used to test the impact of the NRP. RESULTS: A total of 1096 VLBW (500-1499 g) infants were enrolled, and 98.5% of live-born infants were monitored to 7 days. All-cause, 7-day neonatal mortality, stillbirth, and perinatal mortality rates were not affected by ENC or NRP training. CONCLUSIONS: Neither ENC nor NRP training of birth attendants decreased 7-day neonatal, stillbirth, or perinatal mortality rates for VLBW infants born at home or at first-level facilities. Encouragement of delivery in a facility where a higher level of care is available may be preferable when delivery of a VLBW infant is expected.

Biomarkers of trace mineral intake and status.

The emerging public health importance of zinc and selenium and the continuing public health challenges of iron and iodine draw attention to the unmet need for improved biomarkers of trace element status. Currently available biomarkers of these four trace elements are critiqued including the outstanding lack of satisfactory biomarkers for the assessment of zinc intake and status. Other trace elements are reviewed briefly including copper, for which human dietary deficiencies and excesses have been documented, and chromium, which is of possible but unconfirmed public health significance. Evolving strategies of considerable potential include molecular techniques such as the measurement of metallothionein mRNA in lymphocytes as a biomarker of zinc status, an assay that can now be performed with a dried blood spot. The judicious application of tracer techniques also has a role in advancing the quality of zinc biomarkers. Also of special current interest is full definition of the potential of plasma-soluble transferrin receptor concentrations as the biomarker of choice for the detection of early functional iron deficiency.