Kimberly B. Harding

Iodine and Mental Development of Children 5 Years Old and Under: A Systematic Review and Meta-Analysis

Several reviews and meta-analyses have examined the effects of iodine on mental development. None focused on young children, so they were incomplete in summarizing the effects on this important age group. The current systematic review therefore examined the relationship between iodine and mental development of children 5 years old and under. A systematic review of articles using Medline (1980–November 2011) was carried out. We organized studies according to four designs: (1) randomized controlled trial with iodine supplementation of mothers; (2) non-randomized trial with iodine supplementation of mothers and/or infants; (3) prospective cohort study stratified by pregnant women’s iodine status; (4) prospective cohort study stratified by newborn iodine status. Average effect sizes for these four designs were 0.68 (2 RCT studies), 0.46 (8 non-RCT studies), 0.52 (9 cohort stratified by mothers’ iodine status), and 0.54 (4 cohort stratified by infants’ iodine status). This translates into 6.9 to 10.2 IQ points lower in iodine deficient children compared with iodine replete children. Thus, regardless of study design, iodine deficiency had a substantial impact on mental development. Methodological concerns included weak study designs, the omission of important confounders, small sample sizes, the lack of cluster analyses, and the lack of separate analyses of verbal and non-verbal subtests. Quantifying more precisely the contribution of iodine deficiency to delayed mental development in young children requires more well-designed randomized controlled trials, including ones on the role of iodized salt.

Rationale design methodology and sample characteristics for the Vietnam pre-conceptual micronutrient supplementation trial (PRECONCEPT): a randomized controlled study.

BackgroundLow birth weight and maternal anemia remain intractable problems in many developing countries. The adequacy of the current strategy of providing iron-folic acid (IFA) supplements only during pregnancy has been questioned given many women enter pregnancy with poor iron stores, the substantial micronutrient demand by maternal and fetal tissues, and programmatic issues related to timing and coverage of prenatal care. Weekly IFA supplementation for women of reproductive age (WRA) improves iron status and reduces the burden of anemia in the short term, but few studies have evaluated subsequent pregnancy and birth outcomes.The Preconcept trial aims to determine whether pre-pregnancy weekly IFA or multiple micronutrient (MM) supplementation will improve birth outcomes and maternal and infant iron status compared to the current practice of prenatal IFA supplementation only. This paper provides an overview of study design, methodology and sample characteristics from baseline survey data and key lessons learned.Methods/designWe have recruited 5011 WRA in a double-blind stratified randomized controlled trial in rural Vietnam and randomly assigned them to receive weekly supplements containing either: 1) 2800 μg folic acid 2) 60 mg iron and 2800 μg folic acid or 3) MM. Women who become pregnant receive daily IFA, and are being followed through pregnancy, delivery, and up to three months post-partum. Study outcomes include birth outcomes and maternal and infant iron status. Data are being collected on household characteristics, maternal diet and mental health, anthropometry, infant feeding practices, morbidity and compliance.DiscussionThe study is timely and responds to the WHO Global Expert Consultation which identified the need to evaluate the long term benefits of weekly IFA and MM supplementation in WRA. Findings will generate new information to help guide policy and programs designed to reduce the burden of anemia in women and children and improve maternal and child health outcomes in resource poor settings.Trial registrationNCT01665378

Collaboration to optimize dietary intakes of salt and iodine: a critical but overlooked public health issue.

High dietary salt is considered to cause about 30% of cases of hypertension.1 Globally, approximately one quarter of the adult population has hypertension, a leading risk factor for premature death. By 2025 it will affect 1.56 billion adults in the world and more than 90% of those aged 80 years or more will develop hypertension. High salt intake is also linked to other important diseases (such as gastric cancer, obesity, kidney stones and osteoporosis). Based on its impact on blood pressure and gastric cancer, high dietary salt is estimated to be the seventh leading risk factor for premature death in the United States of America and the second leading risk factor in Chile.2,3 High salt intake in low-income countries also has a similar burden of illness and disability. The World Health Organization has recommended reducing salt intake to less than 5 g per day (less than 2000 mg/day) in adult populations.4 Mild-to-moderate iodine deficiency impairs cognitive and motor function and severe iodine deficiency causes hypothyroidism with marked mental and growth retardation.5 The main strategy recommended by the World Health Organization (WHO), the United Nations Children’s Fund (UNICEF) and the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) for correction of iodine deficiency is universal salt iodization.6 Salt iodization to prevent iodine deficiency is a major global public health triumph; it is estimated about 70% of the global population now has access to adequately iodized salt.5 Salt is generally used as the vehicle for providing iodine because it is consumed by most of the population at fairly constant levels throughout the year and its taste and appearance is not affected by iodization. Salt iodization is a highly cost-effective intervention that can be used in low-resource settings. The estimated costs of salt iodization programmes are 0.02 United States dollars (US

Need for coordinated programs to improve global health by optimizing salt and iodine intake

) to US

Integrating nutrition and early child-development interventions among infants and preschoolers in rural India

0.05 per person per year, resulting in a cost of US

Neither Preconceptional Weekly Multiple Micronutrient nor Iron–Folic Acid Supplements Affect Birth Size and Gestational Age Compared with a Folic Acid Supplement Alone in Rural Vietnamese Women: A Randomized Controlled Trial

34–36 per disability-adjusted life year gained (i.e. the cost to avert one year lost due to ill-health, disability or early death caused by iodine deficiency).5 Adverse effects of iodization of salt are uncommon, occur when natural dietary sources of iodine have been adequate and are limited to the rare occurrence of hyperthyroidism.5 Currently recommended average levels of iodine added to salt are within the range of 20–40 mg/kg, based on an estimated average salt consumption of 5–10 g/day in adult populations.6 These levels are safe up to salt intakes of around 25 g/day when the iodine dietary supply is low (as it is in most typical diets in the world). Concerns have been raised that programmes to reduce dietary salt could adversely impact programmes to prevent iodine deficiency disorders (and vice versa).7 However, iodine levels can be increased in salt to adjust for the recommended reduction in dietary salt to less than 5 g/day.7 To adequately adjust the salt fortification programmes, policy-makers should take into account the food consumed, salt and iodine food sources, iodine nutritional requirements of the population and vulnerable subpopulations (young children, pregnant and lactating women). Clearly there is a substantial need to coordinate salt reduction with salt iodization programmes to avoid iodine deficiency. However, each programme involves different public-health communities. We strongly believe that close collaboration between these different groups could enhance both the salt reduction and iodine supplementation programmes. Active nongovernmental organization advocacy is needed with clear messaging on what is required by government, the public and the food industry, including government engagement and oversight of the programmes, evaluation/surveillance, and ongoing negotiations and interactions with the food and salt industries. Many aspects of these activities are common to both programmes therefore there is an opportunity to share and leverage resources and approaches to be more effective and efficient. However, if the programmes to reduce dietary salt and iodine supplementation programmes are not coordinated, they have the potential to confuse policy-makers, the food industry and the public, thereby impeding the health goals. Some countries have selected other methods of providing supplemental iodine than through salt fortification, because use of salt in homes has been replaced by the salt in industry-processed foods. We believe that potential incompatibility of the two programmes is not a valid reason for selecting alternative methods, because the salt used by the food industry should be iodized and at the same time be subject to salt reduction programmes. The Expert Committee convened by the Pan American Health Organization on Optimizing Dietary Salt and Iodine is developing a framework to outline the different actions that are required, planning meetings of larger stakeholder groups and developing a proposal to study the implementation of collaborative salt iodization–salt reduction programmes in countries of the Americas with different economic and nutritional profiles that could serve as model programmes for other countries.

Iron deficiency and anemia control for infants and young children in malaria-endemic areas: a call to action and consensus among the research community

High dietary salt is a major cause of increased blood pressure, the leading risk for death worldwide. The World Health Organization (WHO) has recommended that salt intake be less than 5 g/day, a goal that only a small proportion of people achieve. Iodine deficiency can cause cognitive and motor impairment and, if severe, hypothyroidism with serious mental and growth retardation. More than 2 billion people worldwide are at risk of iodine deficiency. Preventing iodine deficiency by using salt fortified with iodine is a major global public health success. Programs to reduce dietary salt are technically compatible with programs to prevent iodine deficiency through salt fortification. However, for populations to fully benefit from optimum intake of salt and iodine, the programs must be integrated. This review summarizes the scientific basis for salt reduction and iodine fortification programs, the compatibility of the programs, and the steps that need to be taken by the WHO, national governments, and nongovernmental organizations to ensure that populations fully benefit from optimal intake of salt and iodine. Specifically, expert groups must be convened to help countries implement integrated programs and context-specific case studies of successfully integrated programs; lessons learned need to be compiled and disseminated. Integrated surveillance programs will be more efficient and will enhance current efforts to optimize intake of iodine and salt. For populations to fully benefit, governments need to place a high priority on integrating these two important public health programs.

Impact of Preconception Micronutrient Supplementation on Anemia and Iron Status during Pregnancy and Postpartum: A Randomized Controlled Trial in Rural Vietnam

This article describes the development, design, and implementation of an integrated randomized double‐masked placebo‐controlled trial (Project Grow Smart) that examines how home/preschool fortification with multiple micronutrient powder (MNP) combined with an early child‐development intervention affects child development, growth, and micronutrient status among infants and preschoolers in rural India. The 1‐year trial has an infant phase (enrollment age: 6–12 months) and a preschool phase (enrollment age: 36–48 months). Infants are individually randomized into one of four groups: placebo, placebo plus early learning, MNP alone, and MNP plus early learning (integrated intervention), conducted through home visits. The preschool phase is a cluster‐randomized trial conducted in Anganwadi centers (AWCs), government‐run preschools sponsored by the Integrated Child Development System of India. AWCs are randomized into MNP or placebo, with the MNP or placebo mixed into the childrens food. The evaluation examines whether the effects of the MNP intervention vary by the quality of the early learning opportunities and communication within the AWCs. Study outcomes include child development, growth, and micronutrient status. Lessons learned during the development, design, and implementation of the integrated trial can be used to guide large‐scale policy and programs designed to promote the developmental, educational, and economic potential of children in developing countries.

Characterisation of anaemia and associated factors among infants and pre-schoolers from rural India

BACKGROUND Maternal nutritional status before and during early pregnancy plays a critical role in fetal growth and development. The benefits of periconception folic acid (FA) supplementation in the prevention of neural tube defects is well recognized, but the evidence for preconception micronutrient interventions for improving pregnancy outcomes is limited. OBJECTIVE This study aimed to evaluate whether preconception supplementation with weekly iron and folic acid (IFA) or multiple micronutrients (MMs) improves birth outcomes compared with FA alone. METHODS We recruited 5011 women of reproductive age in a double-blind, randomized controlled trial in Vietnam and provided weekly supplements containing either 2800 μg FA, 60 mg Fe and 2800 μg FA (IFA), or the same amount of FA and iron plus other MMs until they conceived (n = 1813). All pregnant women received daily IFA through delivery, and were followed up for birth outcomes, including birth weight, gestational age, preterm delivery and small for gestational age (SGA). Group comparisons were done with the use of ANOVA or chi-square tests for both intention-to-treat (n = 1599) and per-protocol analyses (women consumed supplements ≥26 wk before conception; n = 824). Effect modification by baseline underweight or anemia status was tested with the use of generalized linear models. RESULTS The mean age of the women was 26 y, 30% were underweight, and <10% were nulliparous. The groups were similar for most baseline characteristics. The mean ± SD duration of the preconception intervention was 33 ± 25 wk and compliance was high (>90%). Infants born to the 3 groups of women did not differ (P ≥ 0.05) on mean ± SD birth weight (3076.8 ± 444.5 g) or gestational age (39.2 ± 2.0 wk), or prevalence of SGA (12%), low birth weight (5%) and preterm delivery (10%). There were no significant differences in women who consumed supplements ≥26 wk before conception or by baseline underweight or anemia. CONCLUSION Weekly supplementation with MMs or IFA before conception did not affect birth outcomes compared with FA in rural Vietnamese women. The trial was registered at clinicaltrials.gov as NCT01665378.

Growth and development among infants and preschoolers in rural India: Caregiver protective/promotive factors:

WHO recommendations on iron supplementation for infants and young children in malaria-endemic areas changed dramatically from universal to targeted supplementation for iron-deficient children only, after a trial in a high malaria transmission area showed an increased risk of hospital admission and mortality among iron-replete children following iron and folic acid supplementation. Since this time, there has been much debate and little agreement among the nutrition research community on how to move forward, and country policy and program decision makers have been left with incomplete guidance on how to address young child iron deficiency and anemia in their countries. The focus of a recent symposium during the American Society for Nutrition annual meeting, held in Washington, DC, in April 2011, was on exploring options for addressing iron deficiency and anemia among infants and young children in malaria-endemic areas, now, with safe, effective, and feasible interventions that provide iron. Papers based on the invited presentations are included in this supplement. The first paper is a review of the relationship between iron and malaria. The second is an analysis of theoretical and practical considerations regarding the targeted approach of providing iron and includes results from field testing noninvasive screening devices. This is followed by a review of the safety of universal provision of iron through home-fortification products in malaria-endemic areas. The final papers provide a call to action by highlighting pending research issues (fourth paper) and feasible strategies to move programs forward (fifth paper).