Stunting is prevalent by the age of 6 mo in the indigenous population of the Western Highlands of Guatemala.
The objective of this study was to determine the time course and predictors of linear growth failure and weight-for-age in early infancy.
Study Design and Subjects
One hundred and forty eight term newborns had measurements of length and weight in their homes, repeated at 3 and 6 mo. Maternal measurements were also obtained.
Mean ± SD length-for-age Z-score (LAZ) declined from newborn -1.0 (1.01) to -2.20 (1.05) and -2.26 (1.01) at 3 and 6 mo respectively. Stunting rates for newborn, 3 and 6 mo were 47%, 53% and 56% respectively. A multiple regression model (R2 = 0.64) demonstrated that the major predictor of LAZ at 3 mo was newborn LAZ with the other predictors being newborn weight-for-age Z-score (WAZ), gender and maternal education*maternal age interaction. Because WAZ remained essentially constant and LAZ declined during the same period, weight-for-length Z-score (WLZ) increased from -0.44 to +1.28 from birth to 3 mo. The more severe the linear growth failure, the greater WAZ was in proportion to the LAZ.
The primary conclusion is that impaired fetal linear growth is the major predictor of early infant linear growth failure indicating that prevention needs to start with maternal interventions.
Interference with zinc absorption is a proposed explanation for adverse effects of supplemental iron in iron-replete children in malaria endemic settings. We examined the effects of iron in micronutrient powder (MNP) on zinc absorption after three months of home fortification with MNP in maize-based diets in rural Kenyan infants. In a double blind design, six-month-old, non-anemic infants were randomized to MNP containing 5 mg zinc, with or without 12.5 mg of iron (MNP + Fe and MNP − Fe, respectively); a control (C) group received placebo powder. After three months, duplicate diet collections and zinc stable isotopes were used to measure intake from MNP + non-breast milk foods and fractional absorption of zinc (FAZ) by dual isotope ratio method; total absorbed zinc (TAZ, mg/day) was calculated from intake × FAZ. Mean (SEM) TAZ was not different between MNP + Fe (n = 10) and MNP − Fe (n = 9) groups: 0.85 (0.22) and 0.72 (0.19), respectively, but both were higher than C (n = 9): 0.24 (0.03) (p = 0.04). Iron in MNP did not significantly alter zinc absorption, but despite intakes over double estimated dietary requirement, both MNP groups’ mean TAZ barely approximated the physiologic requirement for age. Impaired zinc absorption may dictate need for higher zinc doses in vulnerable populations.
zinc absorption; micronutrient powders; iron supplementation; malaria; Kenya
The rationale is considered for promoting the availability of local, affordable, non-fortified food sources of bioavailable iron in developing countries. Intakes of iron from the regular consumption of meat from the age of six months are evaluated with respect to physiological requirements. The paper includes a description of two major randomized controlled trials of meat as a first and regular complementary food that are currently in progress. These trials involve poor communities in Guatemala, Pakistan, Zambia, Democratic Republic of the Congo and China.
iron; meat; complementary feeding
To compare iron status in breastfed infants randomized to complementary feeding regimens that provided iron from fortified infant cereals or meats, and examined the development of the enteric microbiota among groups.
Forty-five exclusively breastfed 5 month old infants were randomized to commercially available pureed meats, iron- and zinc-fortified infant cereals, or iron-only fortified infant cereals as the first and primary complementary food through 9–10 months of age. Dietary iron was determined by monthly 3-d diet records. Iron status was assessed at end of the study by hemoglobin (Hb), serum ferritin (SF), and soluble transferrin receptor (STfR) measurements. In a subsample 14 infants, enteric microbiota were profiled in monthly stool samples (5–9 mo) by 16S rRNA gene pyrosequencing.
Infants in cereal groups had 2–3 fold greater daily iron intakes vs the meat group (P < 0.0001). 27% of participants had low SF, and 36% were mildly anemic, without significant differences by feeding group; more infants in meat group had high STfR (p=0.03). Sequence analysis identified differences by time and feeding group in the abundances of several bacterial groups, including significantly more abundant butyrate producing Clostridium Group XIVa in the meat group (P=0.01)
A high percentage of healthy infants who were breastfed-only were iron deficient, and complementary feeding, including iron exposure, influenced the development of the enteric microbiota. If these findings are confirmed, reconsideration of strategies to both meet infants’ iron requirements and optimize the developing microbiome may be warranted.
iron; complementary feeding; breastfeeding; phylogeny; microbiome
The objectives were to determine the range of maternal height associated with growth velocity of older infants and the magnitude of this association in an indigent population. Maternal height and infant length-for-age z scores (LAZ) were positively correlated at both 6 (n=412, r=0.324) and 12 (n=388, r=0.335) months (P<0.0001) and for maternal heights from 131 to 164 cm. Maternal height is independently associated with infant LAZ and stunting (LAZ <−2) at both 6 and 12 months (P<0.001) and with linear growth velocity from 6 to 12 months (P=0.0023).
infant growth; maternal height; stunting
Research directed to optimizing maternal nutrition commencing prior to conception remains very limited, despite suggestive evidence of its importance in addition to ensuring an optimal nutrition environment in the periconceptional period and throughout the first trimester of pregnancy.
This is an individually randomized controlled trial of the impact on birth length (primary outcome) of the time at which a maternal nutrition intervention is commenced: Arm 1: ≥ 3 mo preconception vs. Arm 2: 12-14 wk gestation vs. Arm 3: none.
192 (derived from 480) randomized mothers and living offspring in each arm in each of four research sites (Guatemala, India, Pakistan, Democratic Republic of the Congo). The intervention is a daily 20 g lipid-based (118 kcal) multi-micronutient (MMN) supplement. Women randomized to receive this intervention with body mass index (BMI) <20 or whose gestational weight gain is low will receive an additional 300 kcal/d as a balanced energy-protein supplement. Researchers will visit homes biweekly to deliver intervention and monitor compliance, pregnancy status and morbidity; ensure prenatal and delivery care; and promote breast feeding. The primary outcome is birth length. Secondary outcomes include: fetal length at 12 and 34 wk; incidence of low birth weight (LBW); neonatal/infant anthropometry 0-6 mo of age; infectious disease morbidity; maternal, fetal, newborn, and infant epigenetics; maternal and infant nutritional status; maternal and infant microbiome; gut inflammatory biomarkers and bioactive and nutritive compounds in breast milk. The primary analysis will compare birth Length-for-Age Z-score (LAZ) among trial arms (independently for each site, estimated effect size: 0.35). Additional statistical analyses will examine the secondary outcomes and a pooled analysis of data from all sites.
Positive results of this trial will support a paradigm shift in attention to nutrition of all females of child-bearing age.
Preconception; Maternal; Nutrition; Birth length; Epigenetics; Microbiome
In high-resource settings, obstetric ultrasound is a standard component of prenatal care used to identify pregnancy complications and to establish an accurate gestational age in order to improve obstetric care. Whether or not ultrasound use will improve care and ultimately pregnancy outcomes in low-resource settings is unknown.
This multi-country cluster randomized trial will assess the impact of antenatal ultrasound screening performed by health care staff on a composite outcome consisting of maternal mortality and maternal near-miss, stillbirth and neonatal mortality in low-resource community settings. The trial will utilize an existing research infrastructure, the Global Network for Women’s and Children’s Health Research with sites in Pakistan, Kenya, Zambia, Democratic Republic of Congo and Guatemala. A maternal and newborn health registry in defined geographic areas which documents all pregnancies and their outcomes to 6 weeks post-delivery will provide population-based rates of maternal mortality and morbidity, stillbirth, neonatal mortality and morbidity, and health care utilization for study clusters. A total of 58 study clusters each with a health center and about 500 births per year will be randomized (29 intervention and 29 control). The intervention includes training of health workers (e.g., nurses, midwives, clinical officers) to perform ultrasound examinations during antenatal care, generally at 18–22 and at 32–36 weeks for each subject. Women who are identified as having a complication of pregnancy will be referred to a hospital for appropriate care. Finally, the intervention includes community sensitization activities to inform women and their families of the availability of ultrasound at the antenatal care clinic and training in emergency obstetric and neonatal care at referral facilities.
In summary, our trial will evaluate whether introduction of ultrasound during antenatal care improves pregnancy outcomes in rural, low-resource settings. The intervention includes training for ultrasound-naïve providers in basic obstetric ultrasonography and then enabling these trainees to use ultrasound to screen for pregnancy complications in primary antenatal care clinics and to refer appropriately.
Clinicaltrials.gov (NCT # 01990625)
Maternal mortality; Maternal near miss; Perinatal mortality; Obstetric ultrasound; Low-income countries
Early growth faltering is common but is difficult to reverse after the first 2 years of life.
To describe feeding practices and growth in infants and young children in diverse low-income settings prior to undertaking a complementary feeding trial.
This cross-sectional study was conducted through the Global Network for Women’s and Children’s Health Research in Guatemala, Democratic Republic of Congo, Zambia, and Pakistan. Feeding questionnaires were administered to convenience samples of mothers of 5- to 9-month old infants and 12- to 24-month-old toddlers. After standardized training, anthropometric measurements were obtained from the toddlers. Following the 2006 World Health Organization Growth Standards, stunting was defined as length-for-age < −2SD, and wasting as weight-for-length < −2SD. Logistic regression was applied to evaluate relationships between stunting and wasting and consumption of meat (including chicken and liver and not including fish).
Data were obtained from 1,500 infants with a mean (± SD) age of 6.9 ± 1.4 months and 1,658 toddlers with a mean age of 17.2 ± 3.5 months. The majority of the subjects in both age groups were breastfed. Less than 25% of the infants received meat regularly, whereas 62% of toddlers consumed these foods regularly, although the rates varied widely among sites. Stunting rate ranged from 44% to 66% among sites; wasting prevalence was less than 10% at all sites. After controlling for covariates, consumption of meat was associated with a reduced likelihood of stunting (OR = 0.64; 95% CI, 0.46 to 0.90).
The strikingly high stunting rates in these toddlers and the protective effect of meat consumption against stunting emphasize the need for interventions to improve complementary feeding practices, beginning in infancy.
Complementary feeding; infant growth; infant nutrition; stunting
A previously described mathematical model of Zn absorption as a function of total daily dietary Zn and phytate was fitted to data from studies in which dietary Ca, Fe and protein were also measured. An analysis of regression residuals indicated statistically significant positive relationships between the residuals and Ca, Fe and protein, suggesting that the presence of any of these dietary components enhances Zn absorption. Based on the hypotheses that (1) Ca and Fe both promote Zn absorption by binding with phytate and thereby making it unavailable for binding Zn and (2) protein enhances the availability of Zn for transporter binding, the model was modified to incorporate these effects. The new model of Zn absorption as a function of dietary Zn, phytate, Ca, Fe and protein was then fitted to the data. The proportion of variation in absorbed Zn explained by the new model was 0·88, an increase from 0·82 with the original model. A reduced version of the model without Fe produced an equally good fit to the data and an improved value for the model selection criterion, demonstrating that when dietary Ca and protein are controlled for, there is no evidence that dietary Fe influences Zn absorption. Regression residuals and testing with additional data supported the validity of the new model. It was concluded that dietary Ca and protein modestly enhanced Zn absorption and Fe had no statistically discernable effect. Furthermore, the model provides a meaningful foundation for efforts to model nutrient interactions in mineral absorption.
Mathematical models; Zinc absorption; Calcium; Iron; Protein
Fetal and neonatal mortality rates in low-income countries are at least 10-fold greater than in high-income countries. These differences have been related to poor access to and poor quality of obstetric and neonatal care.
This trial tested the hypothesis that teams of health care providers, administrators and local residents can address the problem of limited access to quality obstetric and neonatal care and lead to a reduction in perinatal mortality in intervention compared to control locations. In seven geographic areas in five low-income and one middle-income country, most with high perinatal mortality rates and substantial numbers of home deliveries, we performed a cluster randomized non-masked trial of a package of interventions that included community mobilization focusing on birth planning and hospital transport, community birth attendant training in problem recognition, and facility staff training in the management of obstetric and neonatal emergencies. The primary outcome was perinatal mortality at ≥28 weeks gestation or birth weight ≥1000 g.
Despite extensive effort in all sites in each of the three intervention areas, no differences emerged in the primary or any secondary outcome between the intervention and control clusters. In both groups, the mean perinatal mortality was 40.1/1,000 births (P = 0.9996). Neither were there differences between the two groups in outcomes in the last six months of the project, in the year following intervention cessation, nor in the clusters that best implemented the intervention.
This cluster randomized comprehensive, large-scale, multi-sector intervention did not result in detectable impact on the proposed outcomes. While this does not negate the importance of these interventions, we expect that achieving improvement in pregnancy outcomes in these settings will require substantially more obstetric and neonatal care infrastructure than was available at the sites during this trial, and without them provider training and community mobilization will not be sufficient. Our results highlight the critical importance of evaluating outcomes in randomized trials, as interventions that should be effective may not be.
Stillbirth; Neonatal mortality; Maternal mortality; Emergency obstetric care
To describe the staffing and availability of medical equipment and medications and the performance of procedures at health facilities providing maternal and neonatal care at African, Asian, and Latin American sites participating in a multicenter trial to improve emergency obstetric/neonatal care in communities with high maternal and perinatal mortality.
In 2009, prior to intervention, we surveyed 136 hospitals and 228 clinics in 7 sites in Africa, Asia, and Latin America regarding staffing, availability of equipment/ medications, and procedures including cesarean section.
The coverage of physicians and nurses/midwives was poor in Africa and Latin America. In Africa, only 20% of hospitals had full-time physicians. Only 70% of hospitals in Africa and Asia had performed cesarean sections in the last 6 months. Oxygen was unavailable in 40% of African hospitals and 17% of Asian hospitals. Blood was unavailable in 80% of African and Asian hospitals.
Assuming that adequate facility services are necessary to improve pregnancy outcomes, it is not surprising that maternal and perinatal mortality rates in the areas surveyed are high. The data presented emphasize that to reduce mortality in these areas, resources that result in improved staffing and sufficient equipment, supplies, and medication, along with training, are required.
emergency obstetric and neonatal care; developing countries; perinatal mortality
To implement a vital statistics registry system to register pregnant women and document birth outcomes in the Global Network for Women’s and Children’s Health Research sites in Asia, Africa, and Latin America.
The Global Network sites began a prospective population-based pregnancy registry to identify all pregnant women and record pregnancy outcomes up to 42 days post-delivery in more than 100 defined low-resource geographic areas (clusters). Pregnant women were registered during pregnancy, with 42-day maternal and neonatal follow-up recorded—including care received during the pregnancy and postpartum periods. Recorded outcomes included stillbirth, neonatal mortality, and maternal mortality rates.
In 2010, 72 848 pregnant women were enrolled and 6-week follow-up was obtained for 97.8%. Across sites, 40.7%, 24.8%, and 34.5% of births occurred in a hospital, health center, and home setting, respectively. The mean neonatal mortality rate was 23 per 1000 live births, ranging from 8.2 to 48.5 per 1000 live births. The mean stillbirth rate ranged from 13.7 to 54.4 per 1000 births.
The registry is an ongoing study to assess the impact of interventions and trends regarding pregnancy outcomes and measures of care to inform public health.
Maternal mortality; Neonatal mortality; Perinatal mortality; Pregnancy; Registry; Stillbirth
Millet is unusually drought resistant and consequently there is a progressive increase in the use of these grains as a human food staple, especially in large areas of India and sub-Saharan Africa. The purpose of this study was to determine the absorption of iron and zinc from pearl millet biofortified with 2 micronutrients that are typically deficient in nonfortified, plant-based diets globally. The study was undertaken in 40 children aged 2 y in Karnataka, India (n = 21 test/19 controls). Three test meals providing ∼84 ± 17 g dry pearl millet flour were fed on a single day for zinc and 2 d for iron between 0900 and 1600 h. The quantities of zinc and iron absorbed were measured with established stable isotope extrinsic labeling techniques and analyses of duplicate diets. The mean (± SD) quantities of iron absorbed from test and control groups were 0.67 ± 0.48 and 0.23 ± 0.15 mg/d, respectively (P < 0.001). The quantities of zinc absorbed were 0.95 ± 0.47 and 0.67 ± 0.24 mg/d, respectively (P = 0.03). These data did not include absorption of the modest quantities of iron and zinc contained in snacks eaten before and after the 3 test meals. In conclusion, quantities of both iron and zinc absorbed when iron and zinc biofortified pearl millet is fed to children aged 2 y as the major food staple is more than adequate to meet the physiological requirements for these micronutrients.
Fecal calprotectin (FC) is an established simple biomarker of gut inflammation. To examine a possible relationship between linear growth and gut inflammation, we compared fecal calprotectin levels in 6 month old infants from poor rural vs affluent urban families.
The project was a cross-sectional comparison of FC from rural and urban populations in China. The relationship between length-for-age Z-score (LAZ) and FC concentrations were also compared. Single fecal samples were assayed for FC using EK-CAL ELISA kits.
The age of subjects for both locations was 6.1 ± 0.2 mo; all were apparently healthy. The mean ± SD of the LAZ for the rural and urban infants were −0.6 ± 0.9 and 0.4 ± 0.9, respectively. FC had a non-normal distribution. The median FC of 420.9 and 140.1 μg/g for rural and urban infants, respectively, were significantly different (P < 0.0001). For the rural group, linear regression analysis showed that an increase in FC of 100 μg/g was associated with a decrease of 0.06 in LAZ.
FC levels were significantly elevated in the rural infants and high concentrations accounted for approximately one-third of the low LAZ scores of these infants.
Fecal calprotectin; Infants; Children; Gut inflammation; Growth
To determine population-based stillbirth rates and to determine whether the timing and maturity of the stillbirths suggest a high proportion of potentially preventable deaths.
Prospective observational study.
Communities in six low-income countries (Democratic Republic of Congo, Kenya, Zambia, Guatemala, India, and Pakistan) and one site in a mid-income country (Argentina).
Pregnant women residing in the study communities.
Over a five-year period, in selected catchment areas, using multiple methodologies, trained study staff obtained pregnancy outcomes on each delivery in their area.
Main outcome measures
Pregnancy outcome, stillbirth characteristics.
Outcomes of 195 400 deliveries were included. Stillbirth rates ranged from 32 per 1 000 in Pakistan to 8 per 1 000 births in Argentina. Three-fourths (76%) of stillbirth off-spring were not macerated, 63% were ≥37 weeks and 48% weighed 2 500g or more. Across all sites, women with no education, of high and low parity, of older age, and without access to antenatal care were at significantly greater risk for stillbirth (p<0.001). Compared to those delivered by a physician, women delivered by nurses and traditional birth attendants had a lower risk of stillbirth.
In these low-middle income countries, most stillbirth offspring were not macerated, were reported as ≥37 weeks’ gestation, and almost half weighed at least 2 500g. With access to better medical care, especially in the intrapartum period, many of these stillbirths could likely be prevented.
Developing countries; intrapartum stillbirth; stillbirth
Nearly half the world’s babies are born at home. We sought to evaluate the training, knowledge, skills, and access to medical equipment and testing for home birth attendants across 7 international sites.
Face-to-face interviews were done by trained interviewers to assess level of training, knowledge and practices regarding care during the antenatal, intrapartum and postpartum periods. The survey was administered to a sample of birth attendants conducting home or out-of-facility deliveries in 7 sites in 6 countries (India, Pakistan, Guatemala, Democratic Republic of the Congo, Kenya and Zambia).
A total of 1226 home birth attendants were surveyed. Less than half the birth attendants were literate. Eighty percent had one month or less of formal training. Most home birth attendants did not have basic equipment (e.g., blood pressure apparatus, stethoscope, infant bag and mask manual resuscitator). Reporting of births and maternal and neonatal deaths to government agencies was low. Indian auxilliary nurse midwives, who perform some home but mainly clinic births, were far better trained and differed in many characteristics from the birth attendants who only performed deliveries at home.
Home birth attendants in low-income countries were often illiterate, could not read numbers and had little formal training. Most had few of the skills or access to tests, medications and equipment that are necessary to reduce maternal, fetal or neonatal mortality.
Home births; Traditional birth attendants; Perinatal mortality
Inadequate and inappropriate complementary feeding are major factors contributing to excess morbidity and mortality in young children in low resource settings. Animal source foods in particular are cited as essential to achieve micronutrient requirements. The efficacy of the recommendation for regular meat consumption, however, has not been systematically evaluated.
A cluster randomized efficacy trial was designed to test the hypothesis that 12 months of daily intake of beef added as a complementary food would result in greater linear growth velocity than a micronutrient fortified equi-caloric rice-soy cereal supplement. The study is being conducted in 4 sites of the Global Network for Women's and Children's Health Research located in Guatemala, Pakistan, Democratic Republic of the Congo (DRC) and Zambia in communities with toddler stunting rates of at least 20%. Five clusters per country were randomized to each of the food arms, with 30 infants in each cluster. The daily meat or cereal supplement was delivered to the home by community coordinators, starting when the infants were 6 months of age and continuing through 18 months. All participating mothers received nutrition education messages to enhance complementary feeding practices delivered by study coordinators and through posters at the local health center. Outcome measures, obtained at 6, 9, 12, and 18 months by a separate assessment team, included anthropometry; dietary variety and diversity scores; biomarkers of iron, zinc and Vitamin B12 status (18 months); neurocognitive development (12 and 18 months); and incidence of infectious morbidity throughout the trial. The trial was supervised by a trial steering committee, and an independent data monitoring committee provided oversight for the safety and conduct of the trial.
Findings from this trial will test the efficacy of daily intake of meat commencing at age 6 months and, if beneficial, will provide a strong rationale for global efforts to enhance local supplies of meat as a complementary food for young children.
Maternal and newborn mortality rates remain unacceptably high, especially where the majority of births occur in home settings or in facilities with inadequate resources. The introduction of emergency obstetric and newborn care services has been proposed by several organizations in order to improve pregnancy outcomes. However, the effectiveness of emergency obstetric and neonatal care services has never been proven. Also unproven is the effectiveness of community mobilization and community birth attendant training to improve pregnancy outcomes.
We have developed a cluster-randomized controlled trial to evaluate the impact of a comprehensive intervention of community mobilization, birth attendant training and improvement of quality of care in health facilities on perinatal mortality in low and middle-income countries where the majority of births take place in homes or first level care facilities. This trial will take place in 106 clusters (300-500 deliveries per year each) across 7 sites of the Global Network for Women's and Children's Health Research in Argentina, Guatemala, India, Kenya, Pakistan and Zambia. The trial intervention has three key elements, community mobilization, home-based life saving skills for communities and birth attendants, and training of providers at obstetric facilities to improve quality of care. The primary outcome of the trial is perinatal mortality. Secondary outcomes include rates of stillbirth, 7-day neonatal mortality, maternal death or severe morbidity (including obstetric fistula, eclampsia and obstetrical sepsis) and 28-day neonatal mortality.
In this trial, we are evaluating a combination of interventions including community mobilization and facility training in an attempt to improve pregnancy outcomes. If successful, the results of this trial will provide important information for policy makers and clinicians as they attempt to improve delivery services for pregnant women and newborns in low-income countries.
Speed of information processing and recognition memory can be assessed in infants using a visual information processing (VIP) paradigm. In a sample of 100 infants 6–8 months of age from Southern Ethiopia, we assessed relations between growth and VIP. The 69 infants who completed the VIP protocol had a mean weight z score of −1.12 ± 1.19 SD, and length z score of −1.05 ± 1.31. The age-appropriate novelty preference was shown by only 12 infants. When age was controlled, longest look duration during familiarization was predicted by weight (sr2 = .16, p = .001) and length (sr2 = .05, p =.058), and mean look duration during test phases was predicted by head circumference (sr2 = .08, p = .018) implying that growth is associated with development of VIP. These data support the validity of VIP as a measure of infant cognitive development that is sensitive to nutritional factors and flexible enough to be adapted to individual cultures.
Infant; Growth; Cognition; Development; Visual information processing; Novelty preference
The etiology of anemia during pregnancy in rural Southern Ethiopia is uncertain. Intakes of animal-source foods are low and infections and bacterial overgrowth probably coexist. We therefore measured the dietary intakes of a convenience sample of Sidama women in late pregnancy who consumed either maize (n = 68) or fermented enset (Enset ventricosum) (n = 31) as their major energy source. Blood samples were analyzed for a complete blood count, vitamin B-12 and folate status, plasma ferritin, retinol, zinc, albumin, and C-reactive protein (CRP). The role of infection and gravida was also examined. Dietary intakes were calculated from 1-d weighed records. No cellular animal products were consumed. Of the women, 29% had anemia, 13% had iron deficiency anemia, 33% had depleted iron stores, and 74 and 27% had low plasma zinc and retinol, respectively. Only 2% had low plasma folate (<6.8 nmol/L) and 23% had low plasma vitamin B-12 (<150 pmol/L), even though 62% had elevated plasma methylmalonic acid (MMA) (> 271 nmol/L). None had elevated plasma cystathionine or total homocysteine (tHcys). Women with enset-based diets had higher (P = 0.052) plasma vitamin B-12 concentration and lower (P < 0.05) cell volume, plasma cystathionine, and retinol than women consuming maize-based diets, but mean hemoglobin, plasma ferritin, MMA, tHcys, and folate did not differ. Plasma zinc, followed by CRP (≤5 mg/L), gravida (≤4), and plasma ferritin (≥12 μmg/L) status were major positive predictors of hemoglobin. Despite some early functional vitamin B-12 deficiency, there was no macrocytic anemia. Consumption of fermented enset may have increased vitamin B-12 levels in diet and plasma.
Calcium fortification of maize has been achieved for millenia in Central America by the process of nixtamalization. Bioavailability of calcium is, however, compromised by phytate, present in large quantities in maize kernels and only modestly reduced by nixtamalization.
The objective of this study was to compare calcium absorption from tortilla meals prepared from low-phytate maize with that from maize with typical phytate content.
Five healthy adult women were fed two test meals of approximately 140g tortillas in lieu of breakfast at one month intervals. On one occasion the tortillas were prepared from maize with approximately 60% phytate reduction (lpa1-1) and on the other occasion from the matching isohybrid wild-type maize. 44Ca (0.3mg/kg body weight) was administered in water as an extrinsic label commencing midway through the test meal and 42Ca (0.06 mg/kg body weight) was administered intravenously immediately after the test meal. Isotope ratios of 42Ca/43Ca and 44Ca/43Ca were measured by inductively-coupled plasma mass spectrometry in urine collected as an eight-hr pool from 16-24 hrs after administration of the intravenous tracer and prepared by the oxalate precipitation method. Fractional absorption of calcium was determined by a dual isotope ratio technique.
Mean fractional absorption from tortillas prepared from the low-phytate maize was 0.50 ± 0.03 compared with a mean of 0.35 ± 0.07 from the control maize (p = 0.01).
The increase in quantity of calcium absorbed could be of practical importance for calcium nutriture when intake of dairy products is limited.
maize; phytate; low-phytate maize alleles; tortillas; calcium absorption
The quantities of zinc and phytate in the diet are the primary factors determining zinc absorption. A mathematical model of zinc absorption as a function of dietary zinc and phytate can be used to predict dietary zinc requirements and, potentially, enhance our understanding of zinc absorption. Our goal was to develop a model of practical and informative value based on fundamental knowledge of the zinc absorption process and then fit the model to selected published data to assess its validity and estimate parameter values. A model of moderate mathematical complexity relating total zinc absorption to total dietary zinc and total dietary phytate was derived and fit to 21 mean data from whole day absorption studies using nonlinear regression analysis. Model validity, goodness of fit, satisfaction of regression assumptions, and quality of the parameter estimates were evaluated using standard statistical criteria. The fit had an R2 of 0.82. The residuals were found to exhibit a normal distribution, constant variance, and independence. The parameters of the model, AMAX, KR, and KP, were estimated to have values of 0.13, 0.10, and 1.2 mmol/d, respectively. Several of these estimates had wide CI attributable in part to the small number and the scatter of the data. The model was judged to be valid and of immediate value for studying and predicting absorption. A version of the model incorporating a passive absorption mechanism was not supported by the available data.
Little is yet known about zinc absorption in late pregnancy, and no information on absorption from the total diet is available.
The objective was to measure the fractional absorption of zinc (FAZ) and to estimate the total quantity of absorbed zinc (TAZ) each day during the third trimester of pregnancy in poor rural southern Ethiopian women.
The participants (n =17) were a convenience sample from a larger study population. The third stage of pregnancy was estimated from fundal height by the Bushulo Health Center prenatal outreach program. FAZ was determined with a dual-isotope tracer ratio technique that uses measurements of urine enrichment with zinc stable isotopes administered intravenously and orally, as an extrinsic label, with all meals in 1 d. Total dietary zinc (TDZ) was calculated from weighed diet records and Ethiopian food-composition tables supported by zinc and phytate analyses of major food items for individual meals. Plasma zinc and exchangeable zinc pool size were also estimated.
Mean (±SD) FAZ was 0.35 ± 0.11, TDZ was 6.0 ± 3.2 mg/d, TAZ was 2.1 ± 1.0 mg/d, phytate intake was 1033 ± 843 mg/d, plasma zinc was 44.1 ± 6.0 μg/dL, and the exchangeable zinc pool size was 142 ± 39 mg. The molar ratio of phytate to zinc was 17:1.
Women from a poor rural population who were dependent on a moderately high-phytate diet had low TDZ and low plasma zinc concentrations in the third trimester of pregnancy. TAZ was modestly higher than that predicted but did not meet physiologic requirements.
Zinc; absorption; phytate; pregnancy; Ethiopia