Iron Nutrition in Schoolchildren of Western Mexico: The Effect of Iron Fortification

In Mexico, food fortification is used as a strategy to combat micronutrient deficiencies. However, little is known about the effects of food fortification in vulnerable populations. This study was carried out in a population of school children believed to be at risk of various micronutrient deficiencies, including iron. The study aimed at determining iron status of children, and identifying and quantifying the sources of iron intake and the presence of relevant enhancers and inhibitors of iron absorption in the diet. The iron status and dietary iron intake was assessed of schoolchildren aged 3–14 years in western Mexico. Hemoglobin, serum ferritin, and transferrin saturation percentages were used to evaluate the iron status in a school-based sample of 762 children. Dietary data were collected from 607 children using semi-quantitative food frequency questionnaires. The overall prevalence of anemia and iron deficiency was 3.7% and 4%, respectively. Iron intake ranged from 1.9 to 3.3 times the recommended daily allowance, with fortified iron accounting for 72% of the total iron intake. Although iron fortification of staples such as maize flour in Mexico for more than a decade most likely contributed to reducing the prevalence of anemia and iron deficiency, the relatively large amounts of iron consumed could eventually lead to problems related to excessive iron intake in some children. Nutritional guidelines for iron fortification in Mexico should be defined and put into practice.     

Iron and vitamin A deficiency in long-term African refugees

Five cross-sectional surveys were conducted in African refugee camps to assess the level of iron deficiency anemia and vitamin A deficiency in populations dependent on long-term international food aid and humanitarian assistance. The prevalence of anemia in children [hemoglobin (Hb) <110 g/L] was high, with >60% affected in 3 of 5 camps. Iron deficiency [serum transferrin receptor (sTfR) >8.5 mg/L] was also high, ranging from 23 to 75%; there was also a strong ecological correlation between the prevalence of iron deficiency and anemia among different camps. Within camps, sTfR predicted the concentration of Hb with adjusted R(2) values ranging from 0.19 to 0.51. Although children were more affected, anemia was also a public health problem in adolescents and women. The effect of recent recommendations on Hb cutoff values for African populations was assessed and found to produce decreases in the prevalence of anemia of between 5 and 21%; this did not affect the public health categorization of the anemia problem within the most affected camps. Mean serum retinol in children, after adjustment for infection status, ranged from 0.72 +/- 0.2 to 0.88 +/- 0.2 micromol/L in the 4 camps assessed and vitamin A deficiency (<0.7 micromol/L) was present at levels ranging from 20.5 to 61.7%. In areas in which vitamin A capsule distribution programs were in effect, coverage ranged from 3.5 up to 66.2%. The high level of micronutrient deficiencies seen in long-term refugees argues in favor of further enhancements in food aid fortification and the strengthening of nutrition and public health programs.     

Iron and folate fortification in the Americas to prevent and control micronutrient malnutrition: an analysis

Although there has been a remarkable decline in the proportion of malnourished children in Latin America, micronutrient deficiencies, especially iron deficiency anemia, remain significant public health problems. A substantial reduction in the prevalence of iron deficiency anemia is an important goal for the end of the decade. Interest in fortifying wheat flour and dry-milled maize flour is thus growing, and significant experience in the fortification of flours with iron and the B vitamins, including folate, is emerging. It is necessary to ensure that fortification levels and standards, legislation, and quality assurance and control measures are in place nationally and harmonized regionally.     

An Assessment of the Impact of Fortification of Staples and Condiments on Micronutrient Intake in Young Vietnamese Children

Targeted fortification programs for infants and young children are an effective strategy to prevent micronutrient deficiencies in developing countries, but the role of large-scale fortification of staple foods and condiments is less clear. Dietary modeling in children aged 6–60 months was undertaken, based on food consumption patterns described in the 2009 national food consumption survey, using a 24-h recall method. Consumption data showed that the median intake of a child for iron, vitamin A and zinc, as a proportion of the Vietnamese Recommended Dietary Allowance (VRDA), is respectively 16%–48%, 14%–49% and 36%–46%, (depending on the age group). Potential fortification vehicles, such as rice, fish/soy sauces and vegetable oil are consumed daily in significant amounts (median: 170 g/capita/day, 4 g/capita/day and 6 g/capita/day, respectively) by over 40% of the children. Vegetable oil fortification could contribute to an additional vitamin A intake of 21%–24% of VRDA recommended nutrient intake, while fortified rice could support the intakes of all the other micronutrients (14%–61% for iron, 4%–11% for zinc and 33%–49% of folate requirements). Other food vehicles, such as wheat flour, which is consumed by 16% of children, could also contribute to efforts to increase micronutrient intakes, although little impact on the prevalence of micronutrient deficiencies can be expected if used alone. The modeling suggests that fortification of vegetable oil, rice and sauces would be an effective strategy to address micronutrient gaps and deficiencies in young children.     

Driving Policy Change to Improve Micronutrient Status in Women of Reproductive Age and Children in Southeast Asia: The SMILING Project

Objective The SMILING (Sustainable Micronutrient Interventions to Control Deficiencies and Improve Nutritional Status and General Health in Asia) project aimed at creating awareness and improving policies around micronutrient deficiencies in five Southeast Asian countries (Vietnam, Laos, Thailand, Cambodia and Indonesia). Results The project showed large gaps in recent data on micronutrient status in most of the five countries. By updating existing, or creating national food composition tables, the SMILING project enabled analyses of food consumption in women of reproductive age and young children. Linear programming showed a high risk for multiple micronutrient deficiencies in these groups, and especially in pregnant women. Most programs to improve micronutrient status target iodine, iron and vitamin A deficiency. However, the high prevalence of zinc, vitamin D, thiamine and folate deficiency in the region warrant interventions too. For certain micronutrients (zinc, iron, calcium), dietary changes alone appeared not enough to fulfill requirements. Food fortification was identified to be a sustainable, long-term solution to improve micronutrient intake. Multiple criteria mapping by stakeholders in each country resulted in a list of country-specific priority interventions. Surprisingly, food fortification was ranked low, due to concerns on quality control and organoleptic changes of the fortified food. More advocacy is needed for new, innovative interventions such as delayed cord clamping. Conclusions for practice The SMILING project recommends regular surveys to monitor micronutrient status of population, to measure impact of interventions and to guide nutrition policies.

     

The role of enriched foods in infant and child nutrition

Since the last century, fortified and enriched foods are products whose original composition has been modified-through addition of essential nutrients-to satisfy specific population needs. For the fortification of foods to have a positive impact on nutritional status, the micronutrients added must be well absorbed and utilized by the organism (bioavailability). Diverse factors affect bioavailability, such as the nutritional status of individuals, the presence in the diet of substances which facilitate or inhibit its absorption, interactions among micronutrients, illnesses, and chemical characteristics of the compound used for fortification. In countries such as Chile, Venezuela and Mexico, important effects have been demonstrated in reducing iron deficiency anaemia in children under 5 years of age. In less than a decade, the salt iodization programme has also proven its effectiveness. Other programmes have fortified foods with Zn, vitamin A and folic acid, which are deficient in infants and children of many populations. In summary, food fortification is a low-cost, relatively simple strategy that may reach a wide range of people, and contribute to reducing the high prevalence of micronutrient deficiencies affecting children, especially in poor countries. The costs due to losses of human capital and their repercussions on health and future development are very high. Building links among academic researchers, politicians, food manufacturers and consumers is essential in order for food fortification to be efficacious and effective, and therefore should be considered as part of an integral strategy to combat micronutrient deficiencies.     

Effect of Fortification with Multiple Micronutrient Powder on the Prevention and Treatment of Iron Deficiency and Anaemia in Brazilian Children: A Randomized Clinical Trial

Fortification with multiple micronutrient powder has been proposed as a public health intervention able to reduce micronutrient deficiencies in children. Our objective was to compare the effectiveness of fortification with multiple micronutrient powder with drug supplementation in the prevention and treatment of iron deficiency and anaemia. This was a cluster trial with anemic and non-anaemic children between six and 42 months old, in randomization data. Non anaemic children received fortification with multiple micronutrient powder or standard drug supplementation of ferrous sulfate associated with folic acid in a prevention dose. Anaemic children who were randomized to receive multiple micronutrient powder also received the recommended iron complementation for anaemia treatment. A total of 162 children were evaluated. The prevalence of anaemia decreased from 13.58 to 1.85%. Iron deficiency decreased from 21.74% to 7.89% (by serum ferritin) and iron deficiency decreased from 66.81 to 38.27% (by soluble transferrin receptor). No difference was identified between interventions for hemoglobin (p = 0.142), serum ferritin (p = 0.288), and soluble transferrin receptor (p = 0.156). Fortification with multiple micronutrient powder was effective in preventing iron deficiency and anaemia in children aged six to 48 months. In anaemic children; it was necessary to supplement the dose of multiple micronutrient powder with ferrous sulfate.     

Can multi-micronutrient food fortification improve the micronutrient status, growth, health, and cognition of schoolchildren? A systematic review

Micronutrient deficiencies compromise the health and development of many school-age children worldwide. Previous research suggests that micronutrient interventions might benefit the health and development of school-age children and that multiple micronutrients might be more effective than single micronutrients. Fortification of food is a practical way to provide extra micronutrients to children. Earlier reviews of (multiple) micronutrient interventions in school-age children did not distinguish between supplementation or fortification studies. The present review includes studies that tested the impact of multiple micronutrients provided via fortification on the micronutrient status, growth, health, and cognitive development of schoolchildren. Twelve eligible studies were identified. Eleven of them tested the effects of multiple micronutrients provided via fortified food compared to unfortified food. One study compared fortification with multiple micronutrients to fortification with iodine alone. Multi-micronutrient food fortification consistently improved micronutrient status and reduced anemia prevalence. Some studies reported positive effects on morbidity, growth, and cognitive outcomes, but the overall effects on these outcomes were equivocal.     

Iron Compounds for Food Fortification: Guidelines for Latin America and the Caribbean 2002

Iron deficiency is the most prevalent micronutrient deficiency in the world today. It affects millions of individuals throughout the life cycle, particularly infants and pregnant women, but also older children, adolescents, and women of reproductive age. Living organisms require iron for their cells to function normally. Iron is needed for the development of vital tissues - including the brain - and for transporting and storing oxygen in hemoglobin and muscle myoglobin. Iron deficiency anemia is the severe form of iron deficiency. It can result in low resistance to infection, impaired psychomotor development, and cognitive function in children, poor academic performance, as well as fatigue and poor physical/work endurance. In addition to the above, iron deficiency anemia in pregnancy can result in a low-birth-weight infant. Three intervention strategies are available to prevent iron deficiency and, therefore, iron deficiency anemia. These are supplementation, dietary diversification, and both targeted and untargeted food fortification. Nineteen countries in the Americas have a national food fortification program, in which iron and other micronutrients are added to at least one widely consumed food that is often wheat and/or corn flour. Table 1 shows the iron compounds added to the flours. Each iron compound has different properties and characteristics, which influence its bioavailability, as is discussed later. A number of countries also currently implement fortification programs targeted to specific groups of the population, primarily infants and young children age 6 to 24 months and school-age children.     

Iron in the diets of rural Honduran women and children

Iron deficiency, a major cause of nutritional anemia, is the most prevalent micronutrient deficiency in the world. One of the main causes of iron deficiency anemia in developing countries is poor availability of absorbable iron from the diet. This study investigates the level of iron intake, bio‐availability, and adequacy in the diets of women and children in the rural west of Honduras. We find that the dietary iron status of this population is very poor. Fifty‐seven percent of the children under one year of age and 23% of 1 to 2 year olds are likely to have inadequate intakes to prevent iron deficiency anemia. Almost all of the pregnant women and 33% of the non‐pregnant non‐lactating women are at risk of developing iron deficiency anemia. The corn based Honduran diet, owing to high phytate levels, has a low bio‐availabiiity for iron. Extremely low intakes of fruits and vegetables and of meats, coupled with significant intake of coffee by all age groups, further limits the availability of dietary iron in the Honduran population.     

Negev nutritional studies: nutritional deficiencies in young and elderly populations.

The importance of nutrition to public health and preventive medicine is evident. Undernutrition is a main nutritional risk factor in the elderly and has been established as a cause of excess morbidity and mortality in different segments of the older population. In the infant population, inadequate nutrition is one of the causes of iron-deficiency anemia, which is associated with impaired physical and cognitive development and lowered immunity. The aim of this paper was to estimate the nutritional pattern and micronutrient deficiencies in elderly and young populations in the Negev. In southern Israel, 351 subjects over 64 years old reported mean dietary intake that was lower than that in younger persons and was independent of the presence of chronic diseases. Current data from southern Israel on healthy Jewish children revealed anemia prevalence of 15% in the second year of life. Data from recent prospective study on Bedouin children showed that anemia affected one quarter of children at age one year. Thus, infants in this area are at high risk for iron deficiency. The findings require the attention of public health authorities and food manufacturers, and should result in a range of activities including publicity and educational programs, fortification of foods, and supplementation programs in high risk-groups.     

Nutritional status of infants and young children and characteristics of their diets

Adoption of the recommended breast-feeding and complementary feeding behaviors and access to the appropriate quality and quantity of foods are essential components of optimal nutrition for infants and young children between ages 6 and 24 mo. Iron, zinc and vitamin B-6 are deficient in complementary food diets in Bangladesh, Ghana, Guatemala, Mexico and Peru. Low intakes of iron are consistent with a high prevalence of anemia seen in this age group. The adequacy of observed intakes for calcium, vitamin A, thiamin, folate and vitamin C depends on the age range in question and the set of requirements used in the assessment. The lipid content of many complementary food diets is low. In addition to providing essential fatty acids, lipids are needed for the absorption of fat-soluble vitamins and also enhance the texture, flavor and aroma of foods, which may lead to increased intake. The relative roles of palatability, micronutrient deficiency and morbidity-induced anorexia in the appetite of infants and young children are not known. However, even among children who were growth retarded and had a total energy deficit compared with requirements, up to 25% of food offered was not consumed. This indicates that dietary quality rather than quantity is the key aspect of complementary food diets that needs to be improved. Targeted fortification or the production of complementary foods fortified with micronutrients and of an adequate macro- and micronutrient composition is one approach to help meet nutritional requirements during the vulnerable period of 6-24 mo.     

A micronutrient-fortified food enhances iron and selenium status of Zambian infants but has limited efficacy on zinc

Micronutrient-fortified, cereal-based infant foods are recommended for reducing multiple micronutrient deficiencies in low-income countries, but their nutritional quality is not always optimal. In a double-blind randomized trial, we compared the efficacy of a locally produced porridge based on maize, beans, bambaranuts, and groundnuts fortified with 19 (rich) or 9 (basal) micronutrients. Infants aged 6 mo from Lusaka, Zambia were randomized to receive the richly fortified (n = 373) or basal (n = 370) porridge daily for 12 mo along with routine vitamin A supplements. Baseline and final micronutrient status and inflammation (based on α-1-glycoprotein) were assessed using nonfasting blood samples. Baseline prevalence of anemia (39%) and zinc deficiency (51%) were a public health concern. There were overall treatment effects on hemoglobin (Hb) (P = 0.001), serum transferrin receptor (P < 0.001), serum ferritin (P < 0.001), and serum selenium (P = 0.009); biomarker responses for iron and zinc were modified by baseline concentrations, and for Hb and iron by socioeconomic status. At 18 mo, the adjusted odds of anemia, iron deficiency anemia (Hb <105 g/L and transferrin receptor > 11.0 mg/L), and iron deficiency were 0.37 (95% CI = 0.25, 0.55), 0.18 (0.09, 0.35), and 0.30 (0.18, 0.50) times those in the basal group, respectively. The rich level of fortification had no overall treatment effect on serum zinc (1.09; 0.66, 1.80) but improved serum zinc in children with lower Hb concentrations at baseline (P = 0.024). A locally produced cereal- and legume-based infant food richly fortified with micronutrients reduced anemia and improved iron and selenium status but may require reformulation to improve the biochemical zinc status of urban Zambian infants.     

What Approaches are Most Effective at Addressing Micronutrient Deficiency in Children 0–5 Years? A Review of Systematic Reviews

Introduction Even though micronutrient deficiency is still a major public health problem, it is still unclear which interventions are most effective in improving micronutrient status. This review therefore aims to summarize the evidence published in systematic reviews on intervention strategies that aim at improving micronutrient status in children under the age of five. Methods We searched the literature and included systematic reviews that reported on micronutrient status as a primary outcome for children of 0–5 years old, had a focus on low or middle income countries. Subsequently, papers were reviewed and selected by two authors. Results We included 4235 reviews in this systematic review. We found that (single or multiple) micronutrient deficiencies in pre-school children improved after providing (single or multiple) micronutrients. However home fortification did not always lead to significant increase in serum vitamin A, serum ferritin, hemoglobin or zinc. Commercial fortification did improve iron status. Cord clamping reduced the risk of anemia in infants up to 6 months and, in helminth endemic areas, anthelminthic treatment increased serum ferritin levels, hemoglobin and improved height for age z-scores. Anti-malaria treatment improved ferritin levels. Discussion Based on our results the clearest recommendations are: delayed cord clamping is an effective intervention for reducing anemia in early life. In helminth endemic areas iron status can be improved by anthelminthic treatment. Anti-malaria treatment can improve ferritin. In deficient populations, single iron, vitamin A and multimicronutrient supplementation can improve iron, vitamin A and multimicronutrient status respectively. While the impact of home-fortification on multimicronutrient status remains questionable, commercial iron fortification may improve iron status.

     

Maize Porridge Enriched with a Micronutrient Powder Containing Low-Dose Iron as NaFeEDTA but Not Amaranth Grain Flour Reduces Anemia and Iron Deficiency in Kenyan Preschool Children

Few studies have evaluated the impact of fortification with iron-rich foods such as amaranth grain and multi-micronutrient powder (MNP) containing low doses of highly bioavailable iron to control iron deficiency anemia (IDA) in children. We assessed the efficacy of maize porridge enriched with amaranth grain or MNP to reduce IDA in Kenyan preschool children. In a 16-wk intervention trial, children (n = 279; 12-59 mo) were randomly assigned to: unrefined maize porridge (control; 4.1 mg of iron/meal; phytate:iron molar ratio 5:1); unrefined maize (30%) and amaranth grain (70%) porridge (amaranth group; 23 mg of iron/meal; phytate:iron molar ratio 3:1); or unrefined maize porridge with MNP (MNP group; 6.6 mg iron/meal; phytate:iron molar ratio 2.6:1; 2.5 mg iron as NaFeEDTA). Primary outcomes were anemia and iron status with treatment effects estimated relative to control. At baseline, 38% were anemic and 30% iron deficient. Consumption of MNP reduced the prevalence of anemia [-46% (95% CI: -67, -12)], iron deficiency [-70% (95% CI: -89, -16)], and IDA [-75% (95% CI: -92, -20)]. The soluble transferrin receptor [-10% (95% CI: -16, -4)] concentration was lower, whereas the hemoglobin (Hb) [2.7 g/L (95% CI: 0.4, 5.1)] and plasma ferritin [40% (95% CI: 10, 95)] concentrations increased in the MNP group. There was no significant change in Hb or iron status in the amaranth group. Consumption of maize porridge fortified with low-dose, highly bioavailable iron MNP can reduce the prevalence of IDA in preschool children. In contrast, fortification with amaranth grain did not improve iron status despite a large increase in iron intake, likely due to high ratio of phytic acid:iron in the meal.     

Micronutrient deficiencies in developing and affluent countries

Micronutrient deficiencies, also known as 'hidden hunger', are determining and aggravating factors for health status and quality of life. Three nutritional problems that have serious consequences are deficiencies of iron, vitamin A and iodine. It is estimated that in today's world, iron deficiency anemia affects two billion people, mostly women and children. Blindness due to vitamin A deficiency affects 2.8 million children under 5 years of age. Iodine deficiency disorders affect 740 million people. Cuba is employing various programs to deal with these micronutrient deficiencies. Dietary diversification, fortification of foods and supplementation with pharmaceutical preparations are included in Cuba's response to these deficiencies. Urban agriculture is one strategy to increase dietary diversity. The aim is to increase both the availability and consumption of vegetables and fruits. Food fortification takes many forms in Cuba today and various supplementation programs are carried out. The most common supplemental program in the country is the prenatal program. This program provides four essential nutrients: iron, ascorbic acid, vitamin A and folic acid. At present, iodination covers more than 90% of the total amount of salt used for human consumption. Results of research carried out in Cuba have shown that vitamin A deficiency is nonexistent in children up to 7 y of age. Foods and preparations for these programs are delivered gratuitously or at very low prices.     

Linking the bioavailability of iron compounds to the efficacy of iron-fortified foods

The bioavailability (relative bioavailability value; RBV) of iron compounds relative to ferrous sulfate has proven useful in ranking the potential of iron compounds for food fortification. The efficacy of iron-fortified foods however depends on the absolute iron absorption from the fortified food and not on the RBV of the iron compound. Compounds of lower RBV can be used to design efficacious fortified foods by adding them at an appropriately higher level. Efficacy thus depends on the amount of iron added to the food vehicle as well as the daily consumption of the fortified food by the target population, the amount of iron lacking in the diet of the target population in relation to their needs, and the prevalence of widespread infections and other micronutrient deficiencies. The World Health Organization has recently published guidelines for food fortification, which include recommendations for iron fortification compounds and a method of how to define the iron fortification level. The same organization has also published guidelines on the iron status methods to be used to monitor interventions. Recent efficacy studies, which have to a large extent followed these guidelines, have shown good efficacy of iron-fortified salt, fish sauce, wheat flour, and rice in improving the iron status of target populations. However, although we now know how to design an efficacious iron-fortified food, efficacy cannot be ensured in populations with widespread infections and other micronutrient deficiencies. In such situations, other public health measures may be necessary before we can ensure an improvement in iron status.     

Zinc and copper: proposed fortification levels and recommended zinc compounds

Micronutrient fortification of foods is now a highly relevant tool worldwide for overcoming micronutrient deficiency. Recent data show that subclinical zinc deficiency is widespread; in Mexico a national survey showed that 25% of children less than age 11 y had plasma zinc concentrations below 10.0 micromol/L (65 microg/dL). Copper deficiency in populations is unknown but copper supplementation is recommended to accompany zinc supplementation. Of the foods available for fortification, staple cereals are very good candidates for reducing micronutrient deficiencies. Because of its higher stability and lower cost, we recommend fortification of cereal flours with zinc oxide, which is absorbed as well as the less stable and more expensive forms of zinc. Depending on the amount of the food that is expected to be eaten, zinc fortification of staple foods could be 20-50 mg/kg of flour. For copper fortification the safer compound is copper gluconate. Copper sulfate is significantly less expensive, but an evaluation of potential physicochemical reactions that affect the final food product is recommended. The suggested amount of copper added to staple foods is 1.2-3.0 mg/kg of flour. For food supplements designed as part of supplementation programs to reduce micronutrient deficiency in children less than age 3 y, a dose of the final product (usually approximately 40-50 g) should contain approximately 4-5 mg of zinc and approximately 0.2-0.4 mg of copper depending on the habitual diet, magnitude of deficiencies and period of supplementation.     

Characterizing Micronutrient Status and Risk Factors among Late Adolescent and Young Women in Rural Pakistan: A Cross-Sectional Assessment of the MaPPS Trial

Nutritional deficiencies are a leading underlying risk factor contributing to the global burden of disease. In Pakistan, late adolescence is considered a nutritionally vulnerable period, as micronutrient requirements are increased to support maturation, and dietary staples are nutrient poor. However, there has been limited evaluation of micronutrient status beyond anemia and its determinants. Using cross-sectional data from late adolescent and young women (15–23 years) at enrolment in the Matiari emPowerment and Preconception Supplementation (MaPPS) Trial, we aimed to describe the prevalence of key micronutrient deficiencies of public health concern, and generate hierarchical models to examine associations with proxies for social determinants of health (SDoH). The prevalence of micronutrient deficiencies was high: 53.6% (95% confidence interval (CI): 53.0–54.3%) had anemia; 38.0% (95% CI: 36.4–39.6%) iron deficiency anemia; 31.8% (95% CI: 30.2–33.3%) vitamin A deficiency; and 81.1% (95% CI: 79.8–82.4%) vitamin D deficiency. At least one deficiency was experienced by 91.0% (95% CI: 90.1–92.0%). Few SDoH were maintained in the final hierarchical models, although those maintained were often related to socioeconomic status (e.g., education, occupation). To improve the micronutrient status of late adolescent and young women in Pakistan, a direct micronutrient intervention is warranted, and should be paired with broader poverty alleviation methods.     

Ensuring the Efficacious Iron Fortification of Foods: A Tale of Two Barriers

Iron fortification of foods has always been a challenge. This is because iron fortification compounds vary widely in relative absorption; because many foods undergo unacceptable changes in color or flavor from the addition of iron; and because many of the iron-fortified foods contain potent inhibitors of iron absorption. These technical barriers have largely been overcome, and efficacious iron-fortified foods, that maintain or improve the iron status of women or children in long-term feeding studies, can be designed. Commercially fortified infant foods are efficacious, and other commercial iron-fortified foods targeted at women and children will provide a useful amount of iron provided the fortification level is adjusted according to the relative absorption of the iron compound. Technologies for the large-scale fortification of wheat and maize flour are also well established, and iron fortification of rice, using the recently developed extruded premix technique, is showing great promise. However, some important knowledge gaps still remain, and further research and development is needed in relation to iron (and iodine)-fortified salt and iron-fortified liquid milk. The usefulness of less-soluble iron compounds, such as ferrous fumarate, to fortify foods for infants and young children in low- and middle-income countries (LMICs) also needs further investigation. A more formidable barrier to efficacious iron-fortified food has been reported in recent years. This is the infection-initiated inflammation barrier, which inhibits iron absorption in response to infection. This barrier is particularly important in LMICs where infections such as malaria and HIV are widespread, and gastrointestinal infections are common due to poor quality water supplies and sanitation. Another source of inflammation in such countries is the high prevalence of obesity in women. Most countries in sub-Saharan Africa have high inflammation which not only decreases the efficacy of iron-fortified and iron-biofortified foods but complicates the monitoring of large-scale iron fortification programs. This is because iron deficiency anemia cannot be differentiated from the more prominent anemia of inflammation and because inflammation confounds the measurement of iron status. There is an urgent need to better quantify the impact of inflammation on the efficacy of iron-fortified foods. However, at present, in LMICs with high inflammation exposure, infection control, cleaner water, improved sanitation, and a decrease in obesity prevalence will undoubtedly have a greater impact on iron status and anemia than the iron fortification of foods.