Iron deficiency anemia: higher prevalence in Mexican American than in non-Hispanic white females in the third National Health and Nutrition Examination Survey, 1988-1994

BACKGROUND: Mexican American females have a higher prevalence of iron deficiency than do non-Hispanic white females. OBJECTIVE: The objective was to estimate the prevalence of iron deficiency anemia and examine potential reasons for this difference between Mexican American (n = 1194) and non-Hispanic white (n = 1183) females aged 12-39 y. DESIGN: We used data from the third National Health and Nutrition Examination Survey (1988-1994). Iron deficiency anemia was defined as abnormal results from >/=2 of 3 tests (erythrocyte protoporphyrin, transferrin saturation, and serum ferritin) and a low hemoglobin concentration. We used multiple logistic regression to adjust for factors that were more prevalent in Mexican American females and significantly associated with iron deficiency anemia. RESULTS: The prevalence of iron deficiency anemia was 6.2 +/- 0.8% (f1.gif" BORDER="0"> +/- SE) in Mexican American females and 2.3 +/- 0.4% in non-Hispanic white females. Mean dietary iron intake, mean serum vitamin C concentrations, and the proportion of females using oral contraceptives were similar in the 2 groups. Age <20 y and education were not associated with iron deficiency anemia. After adjustment for poverty level, parity, and iron supplement use, the prevalence of iron deficiency anemia was 2.3 times higher in Mexican American than in non-Hispanic white females (95% CI: 1.4, 3.9). In those with a poverty income ratio (based on household income) >3.0, however, the prevalence of iron deficiency anemia was 2.6 +/- 0.9% in Mexican American and 1.9 +/- 0.6% in non-Hispanic white females (NS). CONCLUSION: Although much of the ethnic disparity in iron deficiency anemia remains unexplained, factors associated with household income may be involved.     

成本-效益分析法在食物铁强化项目中的应用现状

食物铁强化已经被越来越多的国家作为预防和控制铁缺乏和缺铁性贫血的主要策略。本文就各国食物铁强化项目的成本-效益分析报告进行了综述。目前成本-效益分析的运用范围和影响日益加剧,但是成本-效益方法广泛应用于食物铁强化项目尚待进一步的研究。     

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.     

孕期缺铁性贫血干预方法研究进展

缺铁性贫血是妊娠期最常见的贫血形式,其严重危害孕妇及胎儿健康,可引起早产、低出生体重等不良妊娠结局,对儿童的远期生长发育也能产生重要影响,因此,如何采取有效措施对妊娠期贫血进行预防,其意义深远.目前常见的补铁形式包括单一补铁或铁加其它营养素配伍补铁和孕早期开始预防性增补以及食物强化补铁等多种形式.采取何种方法安全有效地进行补铁是目前研究的热点,该文就近年来不同补铁干预方法的最新研究进展作以综述.     

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 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 status of the Taiwanese elderly: the prevalence of iron deficiency and elevated iron stores

Iron status, prevalence of iron deficiency and elevated iron stores, and the effect of gastrointestinal ulceration on iron status in free-living Taiwanese elderly persons were all assessed in a nationally representative, cross-sectional nutrition survey--the Elderly NAHSIT. The survey included blood measurements of iron indices. Data were collected from 1202 elderly men and 1152 elderly women aged 65 years and older. Multiple iron measures, including serum ferritin (SF), transferrin saturation (Tsat), and hemoglobin were used to evaluate the prevalence of iron deficient erythropoiesis (ID) and iron deficiency anemia (IDA). Despite no routine practice of iron fortification in Taiwan, elderly subjects had a low prevalence of ID and IDA. The prevalence of ID was 2.3% in men and 1.4% in women. The prevalence of IDA was 2.5% in men and 2.0% in women. In contrast, 15.7% of men and 9.8% of women had elevated iron stores as diagnosed by SF>300 microg/L. Subjects with a history of gastrointestinal ulceration had significantly lower serum ferritin than those without ulcers, but the prevalence of anemia, ID and IDA was unaffected. In conclusion, elderly people in Taiwan are an iron-replete population with a high prevalence of elevated iron stores and a low prevalence of iron deficiency.     

Prevention and control of iron deficiency in developing countries

Iron deficiency is a global nutritional problem which mainly affects infants, children, and women of childbearing age. Using anemia as an indicator of iron deficiency, an estimated 30-60% of women and children in developing countries are iron deficient. Even in developed countries, iron deficiency warrants significant public health concern. This paper examines iron deficiency and strategies for its control, with an emphasis upon situations commonly found in developing countries. Sections address anemia and mortality, the effect of iron deficit upon child development and behavior, reduced work performance and productivity, meeting the nutritional requirements for iron in young children and women, general issues in the prevention and control of iron deficiency, nutrition promotion and an education-based approach, iron supplementation programs, the elimination of intestinal helminth infections, food fortification-based interventions for infants and younger children as well as adults, concerns about iron overload related to iron fortification, and an agriculture-based approach.     

Extruded rice fortified with micronized ground ferric pyrophosphate reduces iron deficiency in Indian schoolchildren: a double-blind randomized controlled trial

BACKGROUND: Iron fortification of rice could be an effective strategy for reducing iron deficiency anemia in South Asia. OBJECTIVE: We aimed to determine whether extruded rice grains fortified with micronized ground ferric pyrophosphate (MGFP) would increase body iron stores in children. DESIGN: In a double-blind, 7-mo, school-based feeding trial in Bangalore, India, iron-depleted, 6-13-y-old children (n = 184) were randomly assigned to receive either a rice-based lunch meal fortified with 20 mg Fe as MGFP or an identical but unfortified control meal. The meals were consumed under direct supervision, and daily leftovers were weighed. All children were dewormed at baseline and at 3.5 mo. Iron status and hemoglobin were measured at baseline, 3.5 mo, and 7 mo. RESULTS: At baseline, the prevalences of iron deficiency and iron deficiency anemia in the total sample were 78% and 29%, respectively. After 7 mo of feeding, there was a significant increase in body iron stores in both study groups (P < 0.001), with a greater increase in the iron group than in the control group (P < 0.05). There was a significant time x treatment interaction for iron deficiency, which fell from 78% to 25% in the dewormed iron group and from 79% to 49% in the dewormed control group. Iron deficiency anemia decreased from 30% to 15% (NS) in the iron group but remained virtually unchanged in the control group (28% and 27%). In sensory tests, the MGFP-fortified rice (fortified at 3 and 5 mg Fe/100 g) was indistinguishable from natural rice, in both cooked and uncooked form. CONCLUSIONS: Extruded rice fortified with MGFP has excellent sensory characteristics. Fed in a school lunch meal, it increases iron stores and reduces the prevalence of iron deficiency in Indian children.     

Prevalence of iron deficiency and iron deficiency anemia among three populations of female military personnel in the US Army

BACKGROUND: Iron deficiency is the most prevalent micronutrient deficiency disease in the world and occurs in young women in the United States. Female military personnel represent a unique population faced with intense physical and cognitive demands. OBJECTIVE: The objective of this study was to determine the prevalence of iron deficiency and iron deficiency anemia among three populations of female military personnel in the US Army. METHODS: Iron status was assessed in 1216 volunteers. Volunteers were recruited from three groups: immediately following initial entry to the Army (IET), immediately following basic combat training (AIT), or following at least six months of permanent assignment (PP). Iron deficiency was determined using a three variable model, including cut-off values for serum ferritin, transferrin saturation, and red cell distribution width (RDW). Iron deficiency anemia was categorized by iron deficiency and a hemoglobin (Hgb) value of <12 g/dL. RESULTS: The prevalence of iron deficiency was greater in women in the AIT group (32.8%) than in the IET and PP groups (13.4 and 9.6%, respectively). The prevalence of iron deficiency anemia was greater in the AIT group (20.9%) than in the IET and PP groups (5.8 and 4.8%, respectively). Furthermore, the prevalence of iron deficiency anemia was greater in Hispanic (21.9%) and African-American military personnel (22.9%) than in Caucasian military personnel (10.5%). CONCLUSIONS: These data indicate that female military personnel experience diminished iron status following training, and that iron nutriture is an important issue facing females in the military.     

Prevalence of iron deficiency and iron overload in the adult icelandic population

The aim of this cross-sectional study was to estimate the prevalence of iron deficiency and overload in the adult population in Iceland, a developed Scandinavian country. The study population consisted of 4240 individuals aged 25–74 years randomly selected from the national roster. Basic hematological, S-iron, S-total iron binding capacity (TIBC), and S-ferritin measurements were obtained on 2588 individuals (61.0%). The results indicated unusually large iron stores in the adult Icelandic population and significantly larger iron stores in the rural compared to the urban population. Iron deficiency was rare except in urban premenopausal women, where 1 in 4 showed evidence of iron deficiency and 3.2% had iron deficiency anemia. Seven patients with hereditary hemochromatosis were identified from a subgroup of 1887 subjects, resulting in a prevalence of 0.37%. Two of the hereditary hemochromatosis patients had been gastrectomized. Measures to improve the iron balance in urban premenopausal women cannot therefore include increased iron fortification of food but must be more directed towards the target group.     

Prevalence of iron deficiency with and without concurrent anemia in population groups with high prevalences of malaria and other infections: a study in C?te d'Ivoire.

BACKGROUND: Iron deficiency is highly prevalent in most developing countries. However, its detection is often obscured by infections and inflammatory disorders that are common in the same populations. OBJECTIVE: The aim of this study was to estimate the prevalence of iron deficiency with or without concurrent anemia in different population groups from C?te d'Ivoire and to evaluate the influence of infectious and inflammatory disorders on iron-status indexes. DESIGN: Blood samples from 1573 children, women, and men were analyzed for hemoglobin, serum ferritin, zinc protoporphyrin, and serum transferrin receptor. C-reactive protein was used as the indicator of inflammation or infection, and samples were screened for malarial parasites and hemoglobinopathies. Iron deficiency was defined as 2 of 3 iron-status indexes outside the cutoff values, and iron deficiency anemia (IDA) was defined as iron deficiency with concurrent anemia. Pearson's correlation coefficients were used to evaluate the influence of malaria and inflammation on iron-status indexes. RESULTS: The prevalence of iron deficiency was 41-63% in the women and children and 13% in the men, whereas the prevalence of IDA was 20-39% in the women and children and 4% in the men. The detection of iron deficiency and IDA was obscured by the high prevalence of inflammatory disorders. CONCLUSIONS: Iron deficiency and IDA are highly prevalent in the women and children in C?te d'Ivoire. Iron deficiency was detected in approximately 50% of anemic women and children, which indicates that hemoglobin alone is not a good indicator of iron status when inflammatory disorders are highly prevalent. The serum transferrin receptor is the most useful single indicator of iron deficiency because it was the only iron-status index unaffected by malaria or inflammation.     

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 interventions for women and children in low-income countries

The WHO estimates that 41% of women and 27% of children suffer from anemia due to iron deficiency. The consequences of iron deficiency anemia include suboptimal mental and motor development in young children, increased risk of maternal mortality, and decreased economic productivity of adults. Recent research also provides evidence that maternal iron deficiency in pregnancy increases neonatal morbidity and mortality. This short review briefly highlights how iron interventions might be positioned within 4 global health initiatives: making pregnancy safer, saving newborn lives, infant and young child feeding, and fortification. The importance of iron nutrition is recognized in the context of child nutrition, fortification, and biofortification, and it is likely that meaningful advances will be made through these initiatives in the coming decade. However, iron nutrition is not yet well integrated into the programmatic agendas for reducing morbidity and mortality of pregnant women and neonates. Iron supplementation in pregnancy has been advocated for decades as a means of controlling anemia, but this outcome has not been sufficient to motivate strong programs and policies, and the evidence base is still sparse for high-priority clinical outcomes. To act on the current evidence for maternal and neonatal health will require stronger advocacy within circles that have not traditionally included nutritionists. Successful implementation will require greater attention to antenatal care for pregnancy women and prioritization of iron-promoting actions (including iron supplementation and deworming) within that platform.     

妊娠期铁缺乏和缺铁性贫血对母胎影响的研究进展

妊娠期铁缺乏(Iron Deficiency,ID)和缺铁性贫血(Iron Deficiency Anemia,IDA)是近年产科研究的热点之一。本文综述了近年来国内外文献,概括妊娠期铁缺乏和缺铁性贫血的流行现状,探讨铁缺乏和缺铁性贫血对孕妇和妊娠结局的影响,以及近年来动物实验中铁缺乏和缺铁性贫血对子代的影响。     

Iron deficiency and anemia predict mortality in patients with tuberculosis

Many studies have documented a high prevalence of anemia among tuberculosis (TB) patients and anemia at TB diagnosis has been associated with an increased risk of death. However, little is known about the factors contributing to the development of TB-associated anemia and their importance in TB disease progression. Data from a randomized clinical trial of micronutrient supplementation in patients with pulmonary TB in Tanzania were analyzed. Repeated measures of anemia with iron deficiency, anemia without iron deficiency, and iron deficiency without anemia were assessed as risk factors for treatment failure, TB recurrence, and mortality. The prevalence of anemia (hemoglobin < 110 g/L) at baseline was 64%, more than one-half of which was related to iron deficiency (mean corpuscular volume , 80 fL). We found no evidence of an association between anemia (with or without iron deficiency) or iron deficiency without anemia at baseline and the risk of treatment failure at 1 mo after initiation. Anemia without iron deficiency was associated with an independent, 4-fold increased risk of TB recurrence [adjusted RR = 4.10 (95% CI = 1.88, 8.91); P < 0.001]. Iron deficiency and anemia (with and without iron deficiency) were associated with a 2- to nearly 3-fold independent increase in the risk of death [adjusted RR for iron deficiency without anemia = 2.89 (95% CI = 1.53, 5.47); P = 0.001; anemia without iron deficiency = 2.72 (95% CI = 1.50, 4.93); P = 0.001; iron deficiency anemia = 2.13 (95% CI = 1.10, 4.11); P = 0.02]. Efforts to identify and address the conditions contributing to TB-associated anemia, including iron deficiency, could play an important role in reducing morbidity and mortality in areas heavily affected by TB.     

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.     

Strategies for the Prevention of Iron Deficiency Through Foods in the Household

Iron deficiency can be caused not only by diets deficient in iron but by poor absorption of available dietary iron. Extrinsically tagging foods with radioiron allows the exact measurement of iron absorbed from heme and nonheme iron foods. It has furthered the study of the effect of enhancers and inhibitors of iron absorption. As a result, we have a greater understanding of why iron deficiency and iron deficiency anemia are prevalent in populations of low socioeconomic status and of which food vehicles and irbn compounds are most suitable for iron fortification.     

铁强化食盐预防缺铁性贫血效果的观察

本文试以食盐为载体,使在食盐中每日为学龄前儿童增加元素铁5～10mg,对象为5岁的幼儿园儿童165名,分别在城镇与农村观察一年。初步的结果是:实验组与对照组在开始时的血红蛋白水平一致,但一年后,实验组由原来的平均值11.78±0.57增加至12.72±0.72,比对照组有明显的改善,这是解决缺铁性贫血的一种实际方法。