Rubén Grajeda

Effect of Zinc on Efficacy of Iron Supplementation in Improving Iron and Zinc Status in Women

Iron and zinc may interact in micronutrient supplements and thereby decrease efficacy. We investigated interactive effects of combined zinc and iron supplementation in a randomized controlled trial conducted in 459 Guatemalan women. Four groups were supplemented for 12 weeks: (1) weekly iron and folic acid (IFA); (2) weekly IFA and 30 mg zinc; (3) daily IFA; (4) daily IFA and 15 mg zinc. Effects were assessed by generalized linear regression. Baseline hemoglobin (Hb) concentration was 137.4 ± 15.5 g/L, 13% were anemic and 54% had zinc deficiency. Hb cconcentrations were similar by supplement type, but Hb concentrations improved significantly in anemic women at baseline (increase of 21.8 g/L). Mean percentage changes in serum ferritin were significantly higher in daily compared to weekly supplemented groups (86% versus 32%). The addition of zinc to IFA supplements had no significant impact on iron or zinc status. In conclusion, adding zinc to IFA supplements did not modify efficacy on iron status or improve zinc status, but daily supplementation was more efficacious than weekly in improving iron stores.

Nutritional Supplementation in Early Childhood, Schooling, and Intellectual Functioning in Adulthood: A Prospective Study in Guatemala

OBJECTIVE To estimate the association of improved nutrition in early life with adult intellectual functioning, controlling for years of schooling. DESIGN Prospective cohort study. SETTING Four villages in Guatemala, as well as locations within Guatemala to which cohort members migrated. PARTICIPANTS Individuals who had participated as children in a nutrition supplementation intervention trial from March 1, 1969, through February 28, 1977 (N = 2392). From May 1, 2002, through April 30, 2004, adequate information for analysis was obtained from 1448 of 2118 individuals (68.4%) not known to have died. INTERVENTIONS Individuals exposed to atole (a protein-rich enhanced nutrition supplement) at birth through age 24 months were compared with those exposed to the supplement at other ages or to fresco, a sugar-sweetened beverage. We measured years of schooling by interview. MAIN OUTCOME MEASURES Scores on the Serie Interamericana (InterAmerican Series) tests of reading comprehension and the Raven Progressive Matrices, obtained from May 1, 2002, through April 30, 2004. RESULTS In models controlling for years of schooling and other predictors of intellectual functioning, exposure to atole at birth to age 24 months was associated with an increase of 3.46 points (95% confidence interval, -1.26 to 8.18) and 1.74 points (95% confidence interval, 0.53-2.95) on the InterAmerican Series and Raven Progressive Matrices tests, respectively. There was no statistical interaction between exposure to atole at birth to age 24 months and years of schooling on either outcome (P = .24 and P = .60, respectively). CONCLUSION Improved early-life nutrition is associated with increased intellectual functioning in adulthood after taking into account the effect of schooling.

The human capital study 2002-04: tracking, data collection, coverage, and attrition.

Between 2002 and 2004, the Institute of Nutrition of Central America and Panama (INCAP), in collaboration with Emory University, the International Food Policy Research Institute (IFPRI), and the University of Pennsylvania, re-surveyed young Guatemalan adults who had, as children, been participants in a nutrition supplementation trial conducted by INCAP between 1969 and 1977. This “Human Capital Study 2002–04” complements and extends data obtained in previous studies by collecting new information on measures of physical health and well-being, schooling and cognitive ability, wealth, consumption and economic productivity, and marriage and fertility histories. This paper describes the study domains and data collection procedures. Among 2,393 members of the original sample, 1,856 (77%) were targets for enrollment. Response rates varied by gender, current place of residence, and domain of data collection, with 80% of males and 89% of females completing at least one data collection instrument. Attrition was not random and appears to be associated with a number of initial characteristics of individuals and their households that should be controlled for in future analyses. We conclude that data collection was successful and data quality is high, facilitating the successful undertaking of our planned investigation of important study hypotheses.

Schooling, educational achievement, and cognitive functioning among young Guatemalan adults.

Quantity and quality of schooling obtained and the resulting skills and knowledge acquired are important components of human capital. We describe the distribution of selected measures of schooling, educational achievement, and cognitive functioning among individuals who participated as children in a nutrition supplementation trial in Guatemala and were followed up in 2002–04. Among 1,469 respondents (response rate 80%), who were 26–41 years of age in 2003, more than 90% of men and women had attended at least some school; more than half of men and more than one-third of women had completed sixth grade. Schooling attainment of both men and women has increased across birth cohorts but the schooling gap between men and women has increased. Parental socioeconomic status, as measured in 1975, is a strong predictor of schooling attainment. Basic literacy is high among those studied, with more than 80% able to read simple sentences. The gap in educational achievement favoring men narrowed across birth cohorts due to increases among younger women. The greater performance among men on the Ravens Progressive Matrices test persisted despite increased scores in the younger birth cohorts for both men and women. Migrants to Guatemala City have completed more years of school and scored higher on the tests of educational achievement and cognitive functioning than have cohort members who have remained in the study villages.

Ultrasound measurement of fetal size in rural Guatemala

Objectives: To describe the fetal growth pattern of a population from rural Guatemala and determine when during gestation growth faltering becomes evident. Methods: Ultrasound examinations were conducted for 319 women. Femur length (FL), biparietal diameter (BPD), abdominal (AC) and head circumference (HC) were compared with reference values. Results: FL and AC were similar to reference values throughout gestation. BPD and HC were below the 50th percentile by 30 weeks’ gestation and below the 10th percentile later in gestation. We expected all four dimensions to show marked growth restriction during gestation. Measurement differences may explain the results but would call into question the value of cross‐study comparisons. Infants born small for gestational age were small in all measures as early as 15 weeks. Conclusions: Fetal growth faltering begins in early gestation among infants who were born small. The lack of deviation from reference data for FL and AC requires further clarification.

Fertility behavior and reproductive outcomes among young Guatemalan adults

Fertility rates have declined in many developing countries and this has implications for health and development of subsequent generations. Guatemala has the highest fertility rates in Central America. Reproductive histories were obtained by interview in 2002–04, in a cohort of 779 women and 647 men who had participated as young children in a nutrition supplementation trial in Guatemala conducted between 1969 and 1977. Most women (77%) and men (79%) are currently married. Among the 700 women and 524 men reporting at least one birth, mean age at first birth was 20.7 ± 3.8 years and 23.1 ± 3.9 years respectively. Knowledge (> 80%) and use (∼70%) of modern contraceptive methods is fairly high; knowledge increases with parental socioeconomic status (SES) as measured in 1975. Younger respondents have experienced fewer pregnancies and live births compared with older respondents; age-specific fertility rates between 20 and 24 years were 294, 249, 236, and 261 births per 1,000 women, respectively, for women born from 1962–65, 1966–69, 1969–73, and 1974–77. Women in the top tertile of parental SES have had significantly fewer pregnancies (3.3) compared with those in the middle (3.7) and lower (3.8) tertiles. Migrants to Guatemala City reported greater knowledge of contraceptive methods, fewer pregnancies and living children, higher age at first birth, and more pregnancy and newborn complications as compared with cohort members who remained in the original villages (p < .05 for each comparison). Fertility rates, especially between 20 and 24 years, have declined over time. Differences in reproductive behaviors by parental SES and current residence suggest the role of social transitions in determining family formation in Guatemala.

Experiences and lessons learned for programme improvement of micronutrient powders interventions

Abstract Continual course correction during implementation of nutrition programmes is critical to address factors that might limit coverage and potential for impact. Programme improvement requires rigorous scientific inquiry to identify and address implementation pathways and the factors that affect them. Under the auspices of “The Micronutrient Powders Consultation: Lessons Learned for Operational Guidance,” 3 working groups were formed to summarize experiences and lessons across countries regarding micronutrient powder (MNP) interventions for young children. This paper focuses on how MNP interventions undertook key elements of programme improvement, specifically, the use of programme theory, monitoring, process evaluation, and supportive supervision. Methods included a review of published and grey literature, interviews with key informants, and deliberations throughout the consultation process. We found that although much has been written and published about the use of monitoring and process evaluation to inform MNP interventions at small scale, there has been little formal documentation of lessons for the transition from pilot to scaled implementation. Supervision processes and experiences are not documented, and to our knowledge, there is no evidence of whether they have been effective to improve implementation. Improving the efficiency and effectiveness of interventions requires identification of critical indicators for detecting implementation challenges and drivers of impact, integration with existing programmes and systems, strengthened technical capacity, and financing for implementation of effective monitoring systems. Our understanding of programme improvement for MNP interventions is still incomplete, especially outside of the pilot stage, and we propose a set of implementation research questions that require further investigation.

Elimination of iodine deficiency disorders from the Americas: a public health triumph

Historically, iodine defi ciency disorders aff ected most countries of the Americas. But now, the American continent is celebrating the elimination of iodine defi ciency disorders, a remarkable achievement highlighted at the Micronutrient Forum Global Conference in Cancun, Mexico, on Oct 24–28, 2016. The challenge now is to sustain this achievement. Iodine defi ciency causes goitre, impairs reproductive health and lowers IQ; this spectrum of disorders is termed the iodine defi ciency disorders. Iodine defi ciency disorders were historically widespread in the Americas because of iodine-poor soils, particularly in mountainous areas. Reports during European colonisation described endemic goitre and cretinism in native Americans. In the early 20th century, iodine defi ciency disorders were recognised as a public health problem in most of the countries of the American continent. Endemic goitre was particularly severe in the mountain ranges extending from the Pacifi c northwest, through Mexico and Central America, and the Andes, to the southern tip of Chile. For example, in the goitre belt in the USA and Canada until the 1920s, which included the Pacifi c northwest, the midwest and the Appalachians, 26% to 70% of schoolage children had goiter. According to WHO, based on surveys in Latin America in the 1930s to 1960s, most countries had regions where the goitre prevalence was higher than 50% (fi gure, A). Recognising the severity of the problem, the Pan American Health Organization (PAHO) and WHO founded the Technical Group on Research in Endemic Goiter in 1961, headed by Prof John Stanbury from Harvard University. In a series of meetings between 1963 and 1983, the group defi ned the diagnosis and health consequences of iodine defi ciency disorders and made recommendations for prevention using iodised oil and iodised salt. Pioneering studies in the region identifi ed iodine defi ciency during pregnancy as a cause of irreversible foetal brain damage, and this led to a call for the elimination of iodine defi ciency disorders as an urgent global health priority at the World Summit for Children in 1990. This spurred a commitment by national governments throughout Latin America, working in partnership with UNICEF, PAHO and WHO, and the International Council for the Control of Iodine Defi ciency Disorders (ICCIDD, now the Iodine Global Network). The active presence of ICCIDD in the region since the 1980s has been instrumental in establishing multi-stakeholder coalitions responsible for the sustained success of national universal salt iodisation programmes. From the 1940s to the 1990s, most American countries passed legislation on iodised salt (table). Canada and Costa Rica were the fi rst to mandate iodisation of table salt in the 1940s, and the iodised salt programme in Canada continues to provide adequate iodine to the population: today the national median urinary iodine concentration, the WHO-recommended biomarker of iodine status of populations, is 174 μg/L, indicating adequate iodine intake. The Latin American ThyroMobil study in 2004 documented the remarkable success of iodised salt programmes using standardised urinary iodine concentration methods and thyroid ultrasound: iodine defi ciency disorders had been eliminated in all but one of the 13 countries surveyed in that year. Among the WHO regions, the Americas have had the highest proportion of households consuming well iodised salt for the past two decades. As a result, in 2016, the national median urinary iodine concentration

Risk of excessive intake of vitamins and minerals delivered through public health interventions: objectives, results, conclusions of the meeting, and the way forward: Excessive intake of micronutrients by interventions

The excessive consumption of certain vitamins and minerals could have deleterious consequences on health and development of individuals and populations. Simultaneous micronutrient‐delivery interventions could be challenging in terms of safety as the target populations may overlap, posing a risk of excessive intake of certain micronutrients. The Evidence and Programme Guidance Unit of the Department of Nutrition for Health and Development of the World Health Organization convened a technical consultation on the risk of excessive intake of vitamins and minerals delivered through public health interventions in October 2017. The technical consultations working groups identified important and emerging technical issues, lessons learned, and research priorities related to (1) planning, implementing, monitoring, and evaluating nutrition programs for the detection and control of the risk of excessive intakes; (2) safety, quality control, and assurance considerations; (3) coordination between public health nutrition interventions and other interventions and sectors; and (4) the legislative framework and policy coherence needed for simultaneous nutrition interventions. This paper provides the background and rationale of the technical consultation, synopsizes the presentations, and provides a summary of the main considerations proposed by the working groups.