Wheat flour fortification with folic acid: changes in neural tube defects rates in Chile.

In January 2000, Chilean Ministry of Health mandated the addition of folic acid (FA) to wheat flour in order to reduce the risk of neural tube defects (NTDs). This policy resulted in significant increases in serum and red cell folate in women of fertile age 1 year after fortification. To evaluate the effect of wheat flour fortification on the prevalence of NTDs in Chile we designed a prospective hospital-based surveillance program to monitor the frequency of NTDs in all births (live and stillbirths) with birth weight≥500 g at the nine public maternity hospitals of Santiago, Chile from 1999 to 2009. During the pre-fortification period (1999-2000) the NTD rate was 17.1/10,000 births in a total of 120,566 newborns. During the post-fortification period (2001-2009) the NTD rate decreased to 8.6/10,000 births in a total of 489,915 newborns, which translates into a rate reduction of 50% (RR: 0.5; 95% CI: 0.42-0.59) for all NTDs. The rate reduction by type of NTD studied was: 50% in anencephaly (RR: 0.5; 95% CI: 0.38-0.67), 42% in cephalocele (RR: 0.58; 95% CI: 0.37-0.89), and 52% in spina bifida (RR: 0.48; 95% CI: 0.38-0.6). Rates showed significant reduction both in stillbirths and live births: 510.3 to 183.6/10,000 (RR=0.36; 95% CI: 0.25-0.53) and 13.3 to 7.5/10,000 (RR=0.56; 95% CI: 0.47-0.68), respectively. In Chile, fortification of wheat flour with FA has proven to be an effective strategy for the primary prevention of NTDs.

Plasma zinc concentration, body composition and physical activity in obese preschool children.

Zinc (Zn) deficiency and obesity can be observed together in some developing countries. Zn deficiency may enhance fat deposition and decrease lean mass accrual, which in turn, appears to influence physical activity (PA), although this has not yet been evaluated in obese children. The objective of the study was to find out the association between measurements of plasma Zn and serum leptin, body composition, and PA in Chilean obese preschool children. Seventy-two 18- to 36-month-old obese children [weight-for-length/height z score (WHZ) > 2.0 SD], belonging to low socioeconomic communities, participated in the study. Plasma Zn, serum leptin, weight, waist circumference, height, total body water (TBW) assessed by deuterium isotopic dilution technique and daily activity, measured by registering 48 h with an accelerometer, were evaluated. We found 82% of children with WHZ > 3 SD. The geometric mean Zn intake was 6.2 +/- 2.5 mg/day. The mean plasma Zn was 91.8 +/- 11.4 microg/dL, with 10% of the children having levels <80 microg/dL. No correlation was found between plasma Zn concentrations and either weight, WHZ, or waist circumference. Serum leptin was lower in males than in females (2.9 +/- 2.8 vs 6.8 +/- 5.0 ng/mL, respectively; p < 0.001). TBW was different between males and females (56.2 +/- 5.4 vs 52.8 +/- 4.3% body weight, respectively; p = 0.004), but no significant association was found between TBW and plasma Zn. Moderate + intense PA, (as percentage of wake time), was greater in males than in females (6.3 +/- 3.1% vs 3.4 +/- 2.3%, respectively; p < 0.001), but it was not significantly correlated to plasma Zn. In conclusion, plasma Zn was not associated with body composition as assessed by TBW, serum leptin, or with the magnitude of physical activity in Chilean overweight preschool children.

Usefulness of serum transferrin receptor and serum ferritin in diagnosis of iron deficiency in infancy.

BACKGROUND: The serum transferrin receptor (TfR) and the ratio of TfR to serum ferritin (TfR:SF) have been shown to be useful as early indicators of iron deficiency. OBJECTIVE: The objective of this study was to evaluate the performance of TfR and TfR:SF in the assessment of iron deficiency in infants and to analyze age-related changes in both variables. DESIGN: A total of 716 blood samples obtained from 515 healthy infants aged 8-15 mo were studied. RESULTS: In 144 samples in which all other laboratory indicators of iron status were within the reference range, the median and 95% CI for TfR and TfR:SF were 8.5 mg/L (95% CI: 5.9, 13.5) and 497 (95% CI: 134, 975), respectively. TfR and TfR:SF were significantly correlated with the other laboratory indicators of iron status. Furthermore, as the severity of iron deficiency progressed, there was a gradual increase in mean TfR concentration (P: < 0.00001; analysis of variance). The sensitivity of TfR > 13.5 mg/L and TfR:SF > 975 in the diagnosis of iron deficiency was 23.6% and 68.4%, respectively. The specificity was 98.3% and 63.3% for TfR and TfR:SF, respectively. The sensitivity and specificity of SF < 10 microg/L were 63.7% and 60.8%, respectively. Receiver operator characteristic analysis showed that TfR and TfR:SF were more accurate than was SF alone in the diagnosis of iron deficiency. CONCLUSIONS: TfR and TfR:SF showed age-related changes; TfR and TfR:SF appear to be better diagnostic tests for iron deficiency in infants than SF.

Effect of bovine-hemoglobin-fortified cookies on iron status of schoolchildren: a nationwide program in Chile.

The Chilean School Lunch program, which serves one million children nationwide, was supplied with three 10-g cookies fortified with 6% bovine hemoglobin concentrate, designed to provide 1 mg bioavailable iron per day. A survey of 1000 children was performed after 3 y. Significant differences in hemoglobin concentrations were found in the children from the fortified vs the nonfortified province (P < 0.01). Low serum ferritin values were also significantly more prevalent in the nonfortified group. The effect was evident despite the very low prevalence of anemia in both the fortified and the unfortified school groups. Heme-iron-fortified cookies are a feasible and effective way to improve the iron status of school-age children. In regions of high prevalence of iron-deficiency anemia, the effect of a heme-fortified cookie program should be even more important.

Iron absorption from typical Latin American diets.

The availability and daily absorption of iron was determined by the extrinsic label method in typical lower middle to lower class diets consumed in regions of Argentina, Brazil, Chile, Mexico, Peru, and Venezuela. Differences in iron absorption from meals up to 7-fold, could be attributed to the varying contents of absorption enhancers, eg, in meat, and of inhibitors in tea, vegetables, and wheat or maize bread. The total iron available in the diets from four countries did not meet the physiological requirements for normal subjects but deficient subjects fulfilled their requirements absorbing from 1.0 to 2.1 mg/day. In five diets heme iron (6 to 24% of the total) provided 34 to 73% of the iron absorbed. These data suggest that such absorption and utilization studies may be used to correlate the prevalence of iron deficiency in a population with certain diets and to guide fortification programs.

Bioavailability of iron in soy-based formula and its effect on iron nutriture in infancy.

Soy products have been reported to inhibit absorption of nonheme food iron and fortification iron. Iron bioavailability from a soy formula (Prosobee-PP 710) (iron added as ferrous sulfate: 12 mg/L; ascorbic acid: 54 mg/L) was examined in 16 adult women using the extrinsic radioactive tag method. The geometric mean absorption from the soy formula was only 1.7%. The effect of this formula on iron nutrition in infants was studied in 47 healthy term infants weaned spontaneously before 2 months of age and who received the formula ad libitum until 9 months of age. For control, 45 infants received a cow's milk formula fortified with ferrous sulfate (iron: 15 mg/L; ascorbic acid: 100 mg/L), which has been shown to be effective in preventing iron deficiency, and 49 additional breast-fed infants were also followed. All babies received solid foods (vegetables and meat) starting at 4 months of age. Iron nutritional status was determined at 9 months. Infants fed soy formula and iron-fortified cow's milk had similar mean values of hemoglobin, mean corpuscular volume, transferrin saturation, free erythrocyte protoporphyrin, and serum ferritin; both formula groups differed significantly (P less than .05) from the breast-fed group in all measurements except free erythrocyte protoporphyrin. Anemia (hemoglobin less than 11 g/dL) was present in only 4.3% and 2.2% of infants receiving the soy and the fortified formulas, respectively, v 27.3% in the breast-fed group. These results indicate that soy formula, in spite of the lower iron bioavailability when measured in adults, is essentially as effective as iron-fortified cow's milk in preventing iron deficiency in infants.

Effectiveness of iron-fortified infant cereal in prevention of iron deficiency anemia.

BACKGROUND: Iron deficiency continues to be a common problem among infants throughout the world. Iron-fortified formula is effective in preventing iron deficiency but the benefit of iron-fortified cereal is controversial. METHODS: We compared iron-fortified rice cereal to unfortified rice cereal in infants who were exclusively breast-fed for more than 4 months and to iron-fortified formula in infants who were weaned to formula before 4 months of age. The design was double blind in respect to the presence or absence of fortification iron in the cereal or formula and included 515 infants who were followed on the protocol from 4 to 15 months of age. Rice cereal was fortified with 55 mg of electrolytic iron per 100 g of dry cereal and infant formula with 12 mg of ferrous sulfate per 100 g of dry powder, levels approximating those in use in the United States. Measures of iron status were obtained at 8, 12, and 15 months. Infants with hemoglobin levels of < 105 g/L were excluded from the study and treated. RESULTS: Consumption of cereal reached plateaus at means of about 30 g/d after 6 months of age in the formula-fed groups and 26 g/d after 8 months in the breast-fed groups; these amounts are higher than the 19-g/d mean intake by the 73% of infants who consume such cereal in the United States. Among infants weaned to formula before 4 months, the cumulative percentages of infants excluded for anemia by 15 months were 8%, 24%, and 4%, respectively, in the fortified cereal, unfortified cereal and formula, and fortified formula groups (P < .01 unfortified vs either fortified group; the difference between the two fortified groups was not significant). In infants breast-fed for more than 4 months, the corresponding values were 13% and 27%, respectively, in the fortified and unfortified cereal groups (P < .05). Mean hemoglobin level and other iron status measures were in accord with these findings. CONCLUSION: Iron-fortified infant rice cereal can contribute substantially to preventing iron deficiency anemia.

Haemoglobin-fortified cereal: an alternative weaning food with high iron bioavailability.

Extruded rice flour was fortified with 5 per cent bovine haemoglobin concentrate (BHC). The amino acid score of the product was 59 per cent. The protein efficiency ratio (PER) for the fortified cereal alone was 1.4; however, when given as a mixed diet of cereal and humanized milk (providing 41 and 59 per cent of the protein, respectively) PER was 2.6 (casein standard = 2.5). Iron absorption studies were performed with a double isotope technique, on 10 infants 8-10 months of age. Geometric mean absorption of the rice-BHC iron was 14.2 per cent, as measured with a tag of 55Fe-haemoglobin. The 59Fe-ferrous ascorbate reference dose had a mean absorption of 38.5 per cent. The use of a haem-iron fortified cereal as a weaning food seems feasible and advantageous, supplying an appropriate amount of absorbed iron, an adequate energy density, and a protein which could complement milk protein.

Prevalence of anemia in elderly subjects living at home: role of micronutrient deficiency and inflammation.

OBJECTIVE: Aging is associated with increased risk of developing anemia and micronutrient deficiencies. Wheat-based staple foods are iron fortified in Chile. We aimed to establish the prevalence and etiology of anemia in apparently healthy free-living elderly subjects. DESIGN AND SETTING: A cross-sectional study was performed in an outpatient clinic of Santiago, Chile. SUBJECTS AND METHODS: A group of 274 subjects (93 men, 181 women)>/=60 y old living at home and apparently healthy was studied. Clinical and anthropometric evaluations and dietary survey were performed. Complete blood count, and status of iron, copper, folate, vitamins B12 and A and C-reactive protein, and erythrocyte sedimentation rate were measured. RESULTS: Prevalence of anemia was 5.4% for men and 4.4% for women. Subjects with inflammatory process had a higher prevalence of anemia (22.2% men, 31.6% women). Abnormal serum retinol (<0.35 micromol/l) was found in 13.7% of men and 15.9% of women. Prevalence of folate deficiency (<7 nmol/l) was 50.5% in men and 33.1% in women. Low serum vitamin B12 (<148 pmol/l) was present in 51.1% of men and 30. 9% of women. Iron and copper deficiencies were infrequent. CONCLUSIONS: Anemia is not prevalent in free-living elderly subjects when iron intake is adequate. Inflammatory process is the main etiology of anemia in this age group. Vitamin A, folate and vitamin B12 deficiencies were found in a significant proportion of the study group. SPONSORSHIP: Sandoz Foundation for Gerontological Research.

Haemoglobin fortified cereal: a source of available iron to breast-fed infants.

We tested in the field an extruded rice flour, fortified with a bovine haemoglobin concentrate (Fe:14 mg/100 g of powder). This cereal has a high iron bioavailability, good protein quality and amino acid score. Healthy, term breast-fed infants were prospectively studied. One group (n = 92) received the fortified cereal (from 4 to 12 months of age). As control, 96 infants received regular solid foods (cooked vegetables and meat) from age 4 months. At the end of the field trial, a subsample of infants in both groups was supplemented with 45 mg Fe during 90 d. Iron nutrition status was determined at 9, 12 and 15 months. At 12 months, iron deficiency anaemia was present in 17 per cent of controls, in 10 per cent of fortified infants as a whole, but only in 6 per cent of the babies who consumed over 30 g of cereal/d. In addition, this latter group did not show any significant changes in iron nutrition status after the supplementation trial. Results demonstrate that the consumption of a haemoglobin fortified cereal is effective in markedly reducing the incidence of iron deficiency in breast-fed infants.

[Factors which modify the nutritional state of iron: tannin content of herbal teas]. / Factores que modifican el estado de nutrición de hierro: contenido de taninos de infusiones de hierbas.

Tannins are natural compounds that abound in herbs, wood and fruits. Their numerous hydroxyl radicals confer them a strong avidity for metals such as Fe, Zn and Cu. This property makes them strong inhibitors for the gastrointestinal absorption of these metals. Our purpose was to determine the tannin content of herbal infusions commonly consumed in Chile and other Latino American countries. The determination was performed from dessicated herbs with the Folin-Denis technique. Yerba mate, tea and oregano had the highest tannin content (117, 100 and 84 mg of tannic acid/g dry herb respectively). An intermediate level (between 20 and 40 of tannic acid/g) was for coca, matico, boldo, palto, laurel, orange and binojo. The lowest level of tannin for paico, cedrón, apio and manzanilla (< 10 mg/g). We conclude that the consumption of herbal teas at or around meals may inhibit the absorption of metals such as Fe, Zn, or Cu by decreasing their bioavailability.

[Growth in terms of length of Chilean infants of low socioeconomic status: 1978-1992]. / Crecimiento en talla del lactante chileno de bajo estrato socioeconómico: 1978-1992.

In Chile infant malnutrition is better reflected by the length/age indicator than by weight/length. In this study we will present the progression of length during the first year of life from the year 1978 through 1992 of infants of low socioeconomic status. We selected healthy infants with > 3000 g birth weight and birth length > 0.5 z. According to type of milk feedings they were defined as CM (cow milk) those who were weaned before 4 months of life and EM (exclusive breast milk) those who continued exclusive breast milk (as only source of milk solids permitted) past 6 months. Infants CM of the 1978-80 cohort had a length at birth z +0.21 reaching 1 year with z -0.65, a loss of 0.86 z. Infants from the cohorts of 1982-86 and 1988-92 fell from z +0.15 to z -0.37 (a loss of -0.52 z) and +0.16 to -0.19 (a loss of -0.45 z) between birth and 12 months respectively. EBM infants length also fell significantly (delta z: -1.12, -0.69 and 0.59 respectively). Proteincalorie nutrition was adequate confirmed with weight/age or length/weight curves with means of +0.52 throughout the first year. Analysis of the length curves by regression shows that the slopes of the 3 cohorts are significantly different (< 0.01) for CM and EBM favoring the most recent cohorts. Multiple regression analysis identified association of length at 1 year with birth weight (p < 0.05), birth length (p < 0.01) and socioeconomic index (p < 0.01). We suggest that there is an improvement in the trend of Chilean infants growth in length for the past 20 years, likely due to improvement in socioeconomic level.

[Effect of altitude on iron absorption]. / Efecto de la altura sobre la absorción del hierro.

Iron bioavailability was evaluated in people living in high altitudes. Absorption was estimated from a reference dose of ferrous ascorbate and from a standard diet of wheat flour, using extrinsic tag radioisotope technique of 55Fe and 59Fe. Twenty four volunteers, healthy women, with ages ranging from 28 to 45 years, participated. Of those, eleven lived at 3450 meters above sea level (m.a.s.l.) in Huancayo city-Peru (study group), and 13 lived in Santiago de Chile at 630 m.a.s.l. (control group). Iron absorption from reference dose of ferrous ascorbate was 32.0% and 31.1% in the study and control groups respectively. The geometric mean of iron absorption from the standard diet, corrected to 40% of absorption of reference dose, was 9.0% and 6.9% in the study and control groups respectively (NS). The results suggest that altitude does not produce a high iron absorption in highlander residents.

Nutritional significance of interactions between iron and food components.

Most food iron in the gut enters into two "common pools" that behave quite differently in terms of absorption. Heme iron present in hemoglobin and myoglobin, is well absorbed and is relatively unaffected by diet composition. Non-heme iron, the form of iron present in vegetables and in man's staples, generally is poorly absorbed and is greatly affected by enhancing or inhibiting substances in the diet. In experiments employing intrinsically-labeled hemoglobin as a tracer, absorption of a dry hemoglobin concentrate added to milk, a rice cereal and wheat cookies, was uniformly good, relatively constant and quite independent from the type of food. In contrast, absorption of iron salts decreases markedly when given with food. The presence or absence of inhibiting or enhancing factors of non-heme iron absorption is determinant in the possibility of obtaining required iron for most people in the world whose diet contains little heme iron. Meat and ascorbic acid are the main enhancers of non-heme food iron absorption. Common inhibitors include carbonates, oxalates, phytate, bran, tea and egg yolk. The enhancing effect of ascorbic acid on the absorption of fortification iron in milk and the effect of tea, eggs or meat on the absorption of bread iron from common Chilean meals are discussed as examples of interactions of food components with non-heme iron.

Hemoglobin-fortified biscuits: bioavailability and its effect on iron nutriture in school children.

School-age children in Chile received 30 g of wheat-flour biscuits daily through a National School Lunch Program. To improve iron nutrition, these biscuits were fortified with 6% of a bovine hemoglobin concentrate. Hemoglobin iron bioavailability, measured with a double isotope technique, showed that heme-iron absorption in fortified biscuits was high (19.7%). In a pilot field trial, a cohort of 215 school-children received fortified biscuits (30 g) daily during two school periods, and their iron nutrition status was compared with that of children who received non-fortified biscuits (n = 212). Acceptability of both types of biscuits was excellent. Initially, both groups had comparably good iron nutrition. The fortified children presented higher mean ferritin values at the end of the first and second school periods. Good iron stores (serum ferritin greater than or equal to 20 micrograms/lt) were present in 92% and 79% of the fortified and control subjects, respectively (P less than 0.004). The high-iron bioavailability, the good organoleptic characteristics and the biological effect on iron nutriture make this product an appealing alternative to combat iron deficiency.

[Iron supplementation in Chilean Mapuche infants of the Cautin Province, Chile]. / Suplementación de hierro en lactantes mapuches de la Provincia de Cautin, Chile.

A 1.8 ml iron supplementation of ferrous sulfate is administered for 90 days to 76 Mapuche infants, 12 months of age, male and female, from the rural area of the Cautin province of Chile. The iron nutrition is evaluated before and after the supplementation, through: hemoglobin, haematocrit, transferrin saturation and seric ferritin. Stools test are taken at the infant's home, to confirm the supplement intake and to measure the iron excreted. To study the contained of dietary Fe a Recordatory 24 hour Inquest (RI) is applied moreover a Proximal Chemical Analysis (PCHA) to meal test proceeding from the infant's homes. At 12 months before starting the supplementation, the anemia prevalence was of 28.3%, but it disappear as a result of the intervention. Also 65.3% of the infants showed and increase of 1 g or more on their hemoglobin, which indicates that they were anemic at the beginning of the iron supplementation. By means of this therapeutic test it was find 31% more of anemic infants, indicating more sensibility of this method. The high levels of anemia prevalence are due to the low iron intake, characteristic of the non lactious foods, which according results of the RI reaches an average of 2.8 +/- 1.2 mg of Fe/day, versus 4.8 +/- 4.0 mg of Fe/day according to PCHA. The observed difference between both test showed that there is a process of food environmental contamination, by the use of iron utensils and great soil contact. The high environmental contamination could also be proved by the high iron excretion stools (140 mg of Fe/100 g of stools). This method used to measure the Fe excretion of the supplement, would not be valid in rural population groups with similar characteristics to those of the studied group, because it does not discriminate between the intake and the extremely high environmental contamination. To prevent anemia due to iron absence in infants, it is absolutely necessary to have some iron fortified food starting at 6 months of age, as a complement for breast milk.

[Contribution of iron of bread to the Chilean diet]. / Aporte del hierro del pan a la dieta Chilena.

The content and bioavailability of iron contained in Chilean bread was studied in a random sample from 301 bakeries. A wet digestion procedure followed by a colorimetric method was used. Iron bioavailability was examined in 9 adult women using the extrinsic radioactive tag method. The iron content of bread was 2.4 +/- 0.7 mg/100 g (normally distributed) and 71% of bakeries used wheat flour with adequate iron content. The geometric mean of iron absorption was high (10.5%). Simultaneous ingestion of milk or tea decreased iron absorption by 26 and 35%, respectively. These data suggest that bread represents an important source of iron in the diet of the Chilean population. Iron fortification of bread should be supported and improved nationwide.

[Iron nutritional status in pregnant adolescents at the beginning of gestation]. / Situación de la nutrición de hierro en la embarazada adolescente al inicio de la gestación.

The frequency of anemia and iron nutrition deficiency was assessed in 342 low socioeconomic level pregnant teenagers at entry to prenatal care in 5 outpatient clinics from a South Orient area of Santiago Chile. According to the Center for Disease Control Criteria, 1.2% of women had iron deficiency anemia. Iron stores were insufficient (defined as a serum ferritin lower than 20 g/L) in 55% for women and depleted (serum ferritin lower than 10 g/L) in 21%. Women with more than 14 weeks of gestation had lower packed red cell volumes, hemoglobin, mean corpuscular volumes and ferritin levels than women with less than 14 of gestation. It is concluded that the prevalence of iron deficiency anemia is lower than that predicted for a highly vulnerable group but the high frequency of low iron stores should encourage the use of iron supplementation in these teenagers.

[Nutritional intake of folic acid in breast-fed infants]. / Ingreso nutricional de ácido fólico en lactantes que reciben lactancia materna.

The relationship of natural and artificial feeding to serum and red cell folate levels, as a means of evaluating nutritional intake of this vitamin, was studied. First a cross-sectional study was undertaken in which a group of 112 infants still being breast-fed at 4, 6, and 9 months of age had significantly higher folate concentrations than another group of 102 infants who had been weaned before 2 months. At 6 months of age the prevalence of folic acid deficiency (red cell folate less than 160 micrograms/l of erythrocytes) was 0% in the first group and 15.4% in the second (P less than 0.02), and at 9 months the respective proportions were 3.6 and 28.9% (P less than 0.01). In a second study, 50 nursing infants were followed longitudinally during their first 15 months of life, and up to 9 months of age a direct correlation was observed between the folate concentrations and the duration of breast-feeding. In order to prevent a deficiency of this vitamin, it is recommended that infants be exclusively breast-fed at least through the age of 6 months or, failing this, that they be fed infant formula enriched with folic acid.