Ingesta de calcio y densidad mineral ósea en adolescentes chilenos con desarrollo puberal completo

Introducción: La cantidad diaria recomendada (RDA) de calcio en adolescentes es de 1.300 mg/día. La última Encuesta Nacional de Consumo Alimentario de Chile, mostró que la mediana de ingesta total de calcio fue menos de la mitad de la RDA. Una ingesta insuficiente de calcio puede impactar negativamente la mineralización ósea. Objetivo: Determinar el efecto de la ingesta de calcio y estado nutricional sobre la densidad mineral ósea (DMO) de adolescentes con desarrollo puberal completo. Métodos: Estudio de corte transversal. Participaron n= 79 adolescentes de ambos sexos de entre 17 y 18 años elegidos al azar, aparentemente sanos, estadio Tanner 5 e IMC-1 DE). Según estado nutricional, no hubo diferencias significativas en la ingesta de nutrientes, pero sí en la DMO. En media, la DMO estandarizada (puntaje Z) fue normal para ambos sexos (>-1 DE); los adolescentes con obesidad presentaron una DMO estandarizada significativamente mayor que los adolescentes de peso normal (1,05±0,85 vs 0.33±0,86; P= 0,04). La ingesta de calcio no se relacionó con la masa ósea total ni con la DMO estandarizada. Conclusión: En adolescentes con desarrollo puberal completo no hubo relación entre la ingesta de calcio y los niveles de mineralización ósea. Sí hubo relación entre mineralización ósea y estado nutricional, siendo mayor la DMO en los individuos con obesidad.

Background: In adolescents, the recommended daily intake (RDI) of calcium is 1,300 mg. In Chile, the latest National Survey of Food Consumption showed that the median total calcium intake was less than half of the RDI. An adequate intake of calcium in adolescence negatively affects BMD. Aim: To determine the association of calcium intake and nutritional status with bone mineral density (BMD) in male and female adolescents with completed pubertal development (Tanner 5). Methods: Cross-sectional study in a random sample of 79 male and female adolescents, ages 17-18. Participants were healthy, Tanner stage 5, and BMI −1 SD. BMD was higher in obese participants compared to normal-weight adolescents (1.05±0.85 vs 0.33±0.86; P= 0.04), although no differences in nutrients and food intake. Calcium intake was unrelated to total bone mass and unstandardized BMD. Conclusions: In our sample of adolescents with complete pubertal development, there was no relationship between calcium intake and bone mineralization levels. There was a significant relationship between bone mineralization and nutritional status, with BMD being higher in adolescents with obesity.

Zinc absorption and zinc status are reduced after either sleeve gastrectomy or Roux-en-Y gastric bypass in premenopausal women with severe obesity studied prospectively over 24 postoperative months.

BACKGROUND: Roux-en-Y gastric bypass (RYGBP) is known to reduce zinc absorption; the effects of vertical sleeve gastrectomy (SG) and its long-term implications on zinc absorption have not yet been studied. OBJECTIVE: The aim was to evaluate the effects of SG and RYGBP on zinc absorption and zinc status in premenopausal women with severe obesity up to 24 mo after surgery. METHODS: Twenty-six premenopausal women undergoing SG [BMI (in kg/m2): 37.3 ± 3.2] and 32 undergoing RYGBP (BMI: 42.0 ± 4.2) were studied. A series of anthropometric, dietary, and zinc status parameters (plasma and hair zinc), and the size of the exchangeable zinc pool (EZP), as well as percentage zinc absorption from a standardized dose using a stable isotope methodology were evaluated in the patients before the surgical procedure and at 12 and 24 mo after SG or RYGBP. SG patients received 15 mg and RYGBP received 25 mg of supplemental Zn/d. RESULTS: In premenopausal women, zinc absorption was decreased by 71.9% and 52.0% in SG and RYGBP, respectively, 24 mo postsurgery, compared with initial values. According to 2-factor repeated-measures ANOVA, time effect was significant (P = <0.0001), but not time × group interaction (P = 0.470). Plasma zinc below the cutoff point of 70 µg/dL increased from 0 to 15.4% and 38.1% in SG and RYGBP, respectively. Mean EZP was significantly reduced 24 mo after surgery, although no time × group interactions were observed. Hair zinc did not change across time or between groups. CONCLUSIONS: Both SG and RYGBP have profound effects on zinc absorption capacity, which are not compensated for after 24 mo. Although zinc absorption reduction was similar in both types of surgeries, plasma zinc was more affected in RYGBP than SG, despite greater zinc supplementation in RYGBP.This trial was registered at http://www.isrctn.com as ISRCTN31937503.

Exploratory Study: Excessive Iron Supplementation Reduces Zinc Content in Pork without Affecting Iron and Copper.

The aim of this work was to determine in an exploratory manner the effect of excessive iron supplementation on iron, zinc, and copper contents in pork and pork offal. Pigs averaging 50 days in age and 15 ± 1.3 kg body weight were allocated to a control group (500 ppm dietary Fe) and a supplemental group (3000 ppm dietary Fe). After an iron supplementation period of 60 days, blood samples were analyzed to determine iron biomarkers, serum copper, and zinc contents. Animals were slaughtered to assess total iron, non-heme iron, heme iron, zinc, and copper contents in samples of nine meat cuts and some offal. Iron supplementation improved the iron status in pigs with increased hemoglobin and hematocrit, but did not affect serum levels of iron, zinc, and copper. Iron supplementation did not affect the heme and non-heme iron contents of the different meat cuts. Zinc contents decreased by 32-55% in meat cuts, where iron content increased in the liver, spleen, kidneys, and pancreas. No differences of zinc and copper were observed in offal samples. High concentrations of iron supplementation reduce zinc content in pork.

Effect of various calcium salts on non-heme iron bioavailability in fasted women of childbearing age.

INTRODUCTION: Micronutrient deficiencies are one of the most important public health issues worldwide and iron (Fe) deficiency anemia is the most prevalent micronutrient deficiency. Iron deficiency often coexists with calcium deficiency and iron and calcium supplementation often overlap. This has led to investigations into the interaction between these two minerals, and whether calcium may inhibit iron absorption in the gut. OBJECTIVE: To determine the effect of various calcium salts on non-heme iron bioavailability in fasted women of childbearing age. METHODS: A randomized and single blinded trial was conducted on 27 women of childbearing age (35-45 years old) divided into 2 groups (n1 = 13 and n2 = 14, respectively). On four different days, after an overnight fast, they received 5 mg of Fe as FeSO4 (labeled with 55Fe or 59Fe) with 800 mg of elemental calcium in the form of either calcium chloride, calcium gluconate, calcium citrate, calcium carbonate, calcium lactate, calcium sulfate or calcium phosphate. Calcium chloride was used as the control salt in both groups. Iron was labeled with the radioisotopes 59Fe or 55Fe, and the absorption of iron was measured by erythrocyte incorporation of radioactive Fe RESULTS: 800 mg of elemental calcium as calcium citrate produced a significant decrease in non-heme iron bioavailability (repeated measures ANOVA, F = 3.79, p = 0.018). CONCLUSION: Of the various calcium salts tested, calcium citrate was the only salt that decreased non-heme iron bioavailability relative to the calcium chloride control when taken on an empty stomach. These results suggest that inhibition of non-heme iron absorption in fasted individuals is dependent upon the calcium salt in question and not solely dependent on the presence of calcium.

Pectin Esterification Degree in the Bioavailability of Non-heme Iron in Women.

Pectins are a type of soluble fiber present in natural and processed foods. Evidence regarding the effect of esterification degree of pectins on iron absorption in humans is scarce. In the present study, the effect of pectins with different degrees of esterification on non-heme iron absorption in women was evaluated. A controlled experimental study was conducted with block design, involving 13 apparently healthy, adult women. Each subject received 5 mg Fe (FeSO4) without pectin (control) or accompanied by 5 g citrus pectin, two with a low degree of esterification (27 and 36%), and one with a high degree of esterification (67 to 73%), each on different days. Each day, the 5 mg Fe doses were marked with radioactive 59Fe or 55Fe. Radioactivity incorporated into erythrocytes was determined in blood samples 14 days after the marked Fe doses were consumed. On days 18 and 36 of study, 30 and 20 mL blood samples were obtained, respectively, and blood sample radioactivity incorporated into erythrocytes was determined. Body iron status was determined from blood taken on day 18. Whole body blood volume was estimated for calculate iron bioavailability; it was assumed that 80% of absorbed radioactivity was incorporated into the Hb. All women participants signed an informed consent of participation at baseline. Iron bioavailability (mean geometric ±1 SD) alone (control) was 18.2% (12.3-27.1%), iron + pectin27 was 17.2% (10.2-29.2%), iron + pectin36 was 15.3% (9.5-24.6%), and iron + pectin67 was 19.5% (10.0-38.0%). No statistically significant differences between iron bioavailability (repeated measures ANOVA, p = 0.22) were observed. Pectin esterification degree does not influence the bioavailability of non-heme iron in women.

Prebiotics increase heme iron bioavailability and do not affect non-heme iron bioavailability in humans.

The aim of this study was to establish the effect of a prebiotic mix on heme and non-heme iron (Fe) bioavailability in humans. To this purpose, twenty-four healthy women were randomized into one of two study groups. One group ate one yogurt per day for 12 days with a prebiotic mix (prebiotic group) and the other group received the same yogurt but without the prebiotic mix (control group). Before and after the intake period, the subjects participated in Fe absorption studies. These studies used 55Fe and 59Fe radioactive isotopes as markers of heme Fe and non-heme Fe, respectively, and Fe absorption was measured by the incorporation of radioactive Fe into erythrocytes. The results showed that there were no significant differences in heme and non-heme Fe bioavailability in the control group. Heme Fe bioavailability of the prebiotic group increased significantly by 56% post-prebiotic intake. There were no significant differences in non-heme Fe bioavailability in this group. We concluded that daily consumption of a prebiotic mix increases heme Fe bioavailability and does not affect non-heme iron bioavailability.

The effect of proteins from animal source foods on heme iron bioavailability in humans.

Forty-five women (35-45 year) were randomly assigned to three iron (Fe) absorption sub-studies, which measured the effects of dietary animal proteins on the absorption of heme Fe. Study 1 was focused on heme, red blood cell concentrate (RBCC), hemoglobin (Hb), RBCC+beef meat; study 2 on heme, heme+fish, chicken, and beef; and study 3 on heme and heme+purified animal protein (casein, collagen, albumin). Study 1: the bioavailability of heme Fe from Hb was similar to heme only (∼13.0%). RBCC (25.0%) and RBCC+beef (21.3%) were found to be increased 2- and 1.6-fold, respectively, when compared with heme alone (p<0.05). Study 2: the bioavailability from heme alone (10.3%) was reduced (p<0.05) when it was blended with fish (7.1%) and chicken (4.9%), however it was unaffected by beef. Study 3: casein, collagen, and albumin did not affect the bioavailability of Fe. Proteins from animal source foods and their digestion products did not enhance heme Fe absorption.

Acute Copper and Ascorbic Acid Supplementation Inhibits Non-heme Iron Absorption in Humans.

The objective of the study is to determine the effect of copper (Cu) plus the reducing agent ascorbic acid (AA) on the absorption of non-heme iron (Fe). Experimental study with block design in which each subject was his own control. After signing an informed consent, 14 adult women using an effective method of contraception and negative pregnancy test received 0.5 mg Fe, as ferrous sulfate, alone or with Cu, as copper sulfate, plus ascorbic acid (AA/Cu 2/1 molar ratio) at 4/1; 6/1 and 8/1 Cu/Fe molar ratios as an aqueous solution on days 1, 2, 14, and 15 of the study. Fe absorption was assessed by erythrocyte incorporation of iron radioisotopes (55)Fe and (59)Fe. Geometric mean (range ± SD) absorption of Fe at 4/1 and 6/1 Cu/Fe molar ratios (and AA/Cu 2/1 molar ratio) and Fe alone was 57.4 % (35.7-92.1 %), 64.2 % (45.8-89.9 %), and 38.8 % (20.4-73.8 %), respectively (ANOVA for repeated measures p < 0.001; post hoc test Scheffé, p < 0.05). This is attributable to the enhancing effect of AA on non-heme Fe absorption; however, Fe absorption at Cu/Fe 8/1 molar ratio was 47.3 % (27.7-80.8) (p = NS compared with Fe alone). It was expected that Fe absorption would have been equal or greater than at 4/1 and 6/1 molar ratios. Copper in the presence of ascorbic acid inhibits non-heme Fe absorption at Cu/Fe 8/1 molar ratio.

Iron Absorption from Two Milk Formulas Fortified with Iron Sulfate Stabilized with Maltodextrin and Citric Acid.

BACKGROUND: Fortification of milk formulas with iron is a strategy widely used, but the absorption of non-heme iron is low. The purpose of this study was to measure the bioavailability of two iron fortified milk formulas designed to cover toddlers´ nutritional needs. These milks were fortified with iron sulfate stabilized with maltodextrin and citric acid. METHODS: 15 women (33-47 years old) participated in study. They received on different days, after an overnight fast, 200 mL of Formula A; 200 mL of Formula B; 30 mL of a solution of iron and ascorbic acid as reference dose and 200 mL of full fat cow's milk fortified with iron as ferrous sulfate. Milk formulas and reference dose were labeled with radioisotopes (59)Fe or (55)Fe, and the absorption of iron measured by erythrocyte incorporation of radioactive Fe. RESULTS: The geometric mean iron absorption corrected to 40% of the reference dose was 20.6% for Formula A and 20.7% for Formula B, versus 7.5% of iron fortified cow's milk (p < 0.001). The post hoc Sheffé indeed differences between the milk formulas and the cow's milk (p < 0.001). CONCLUSION: Formulas A and B contain highly bioavailable iron, which contributes to covering toddlers´ requirements of this micronutrient.

The Effect of Plant Proteins Derived from Cereals and Legumes on Heme Iron Absorption.

The aim of this study is to determine the effect of proteins from cereals and legumes on heme iron (Fe) absorption. The absorption of heme Fe without its native globin was measured. Thirty adult females participated in two experimental studies (15 per study). Study I focused on the effects of cereal proteins (zein, gliadin and glutelin) and study II on the effects of legume proteins (soy, pea and lentil) on heme Fe absorption. When heme was given alone (as a control), study I and II yielded 6.2% and 11.0% heme absorption (p > 0.05). In study I, heme Fe absorption was 7.2%, 7.5% and 5.9% when zein, gliadin and glutelin were added, respectively. From this, it was concluded that cereal proteins did not affect heme Fe absorption. In study II, heme Fe absorption was 7.3%, 8.1% and 9.1% with the addition of soy, pea and lentil proteins, respectively. Only soy proteins decreased heme Fe absorption (p < 0.05). These results suggest that with the exception of soy proteins, which decreased absorption, proteins derived from cereals and legumes do not affect heme Fe absorption.

Effect of daily supplementation with iron and zinc on iron status of childbearing age women.

The objective was to determine the effect of daily supplementation with 30 mg of iron (Fe) plus 30 mg of zinc (Zn) for 3 months on Fe status of women of childbearing age. This was a randomized double-blind, placebo-controlled trial. Eighty-one women (18-45 years) were randomly assigned to receive either a daily single dose of 30 mg of Fe (group 1; n = 28) and 30 mg of Fe plus 30 mg of Zn (group 2; n = 26) or placebo (n = 27) for 3 months. Hemoglobin (Hb), mean corpuscular volume, serum Fe, total iron-binding capacity, transferrin saturation, erythrocyte Zn protoporphyrin, serum ferritin (SF), serum transferrin receptor (TfR), total body Fe, serum Zn, and high-sensitivity C-reactive protein were measured at baseline and at the end of the study. At baseline, 3.7, 28.4, and 3.7 % of women had iron-deficiency anemia (IDA), Fe deficiency without anemia, and depleted Fe stores, respectively. No significant differences on Fe status were found between groups before supplementation. After supplementation, group 2 showed a significant increase of Hb and total body Fe and a significant decrease of TfR compared with placebo (p < 0.05). Moreover, serum Zn increased significantly in group 2 compared with group 1 (p < 0.01) and placebo (p < 0.01). In conclusion, daily supplementation with 30 mg of Fe plus 30 mg of Zn for 3 months improved significantly the Fe and Zn status of women, compared with those who received placebo. The positive effect of Fe supplementation on Fe status is enhanced by combined Zn supplementation.

Effect of phytic acid, tannic acid and pectin on fasting iron bioavailability both in the presence and absence of calcium.

OBJECTIVE: To determine the effect of phytic acid, tannic acid and pectin on fasting non-heme iron bioavailability in both the presence and absence of calcium. RESEARCH METHODS: Twenty-eight apparently healthy adult females participated in two iron absorption studies using radioactive iron isotopes ((59)Fe and (55)Fe). One group received 5mg of iron (as FeSO4) alone (control), together with 10mg of phytic acid, 100mg of tannic acid and 250mg of pectin (study A), on different days. The second group received the same iron doses and compounds as the other group, plus 800mg of calcium (CaCl2) (study B). The compounds were administered after an overnight fast, and no food or beverages were consumed for the following 3h. Iron status and circulating radioactivity were measured in venous blood samples. RESULTS: The geometric means of iron bioavailability (range±1SD) for iron alone, iron with phytic acid, iron with tannic acid, and iron with citrus pectin were 25.0% (11.9-52.0); 18.9% (9.9-35.8); 16.8% (8.7-32.3); and 21.1% (10.2-43.9), respectively (repeated-measures ANOVA, p<0.02 (Dunnett's post hoc: control vs tannic acid p<0.05). When 800mg of calcium was added (study B), iron bioavailability was 16.7% (10.1-27.5); 13.2% (7.1-24.6); 14.8% (8.8-25.1); and 12.6% (5.5-28.8), respectively (repeated-measures ANOVA, NS). CONCLUSIONS: Tannic acid decreases the fasting bioavailability of non-heme iron, however this effect did not exist in the presence of calcium. No effect was observed by phytic acid or citrus pectin on fasting non-heme iron bioavailability in both the presence and absence of calcium.

Body mass index, iron absorption and iron status in childbearing age women.

BACKGROUND: The prevalence of obesity has increased at an alarming rate worldwide. Some studies have observed an association between iron (Fe) deficiency (ID) and obesity, however more research is needed. OBJECTIVE: To assess whether body mass index (BMI) is associated with both Fe absorption and Fe status. METHODS: A cross sectional sample of 318 Chilean childbearing age women was studied. The women received either a single dose of 0.5mg of Fe (n=137, group 1) or 3mg of Fe plus ascorbic acid (1:2 molar ratio) (n=181, group 2), both as FeSO4 with labeled radioisotopes. Fe absorption was assessed through radio Fe erythrocyte incorporation. Fe status was determined by hemoglobin (Hb), mean corpuscular volume, serum Fe, total iron binding capacity, transferrin saturation, erythrocyte Zn protoporphyrin and serum ferritin (SF). RESULTS: 29%, 47% and 24% of the women were classified as normal, overweight or obese, respectively. Fe absorption was significantly lower in obese women (p<0.05). In group 1, the geometric mean and range ±1 SD of the percentage of Fe absorption for normal-weight women was 32.9% vs. 19.7% in obese. For group 2, this percentage was 36% vs. 30%, respectively (2-way ANOVA: BMI classification and Fe dose p<0.05; interaction p=0.34). Although Fe absorption was lower in obese women, they had higher SF (p<0.01) and Hb (p<0.05) concentrations. CONCLUSION: Although we did not observe a relationship between BMI and Fe status, obese women displayed lower Fe absorption compared with overweight and normal weight women, possibly due to subclinical inflammation associated with obesity.

Variación estacional del perfil lipídico en adultos aparentemente sanos de Santiago, Chile / Seasonal variations in the lipid profile of apparently healthy young adults living in Santiago, Chile.

El perfil lipídico depende de muchos factores. Sin embargo, las variaciones estacionales de estos componentes han sido escasamente establecidas en el hemisferio sur. El objetivo de este estudio fue determinar la variación estacional del perfil lipídico por un periodo de un año en un grupo de adultos aparentemente sanos de Santiago, Chile. El diseño del estudio fue observacional y prospectivo. Participaron en el estudio 50 voluntarios sanos de ambos sexos y de edades entre 23 a 62 años. En forma mensual y durante un año se midió el perfil lipídico. LDL fue significativamente mayor en invierno y primavera que en verano (p<0,01). Por el contrario HDL disminuye en invierno (p<0,05). Se concluye que existen variaciones estacionales en los niveles séricos de LDL y HDL. El patrón circanual está caracterizado por mayores niveles de LDL en invierno y primavera y menores niveles de HDL en invierno.

The lipid profile is impacted by numerous factors. However, the seasonal variations in this profile have not been well-established in the southern hemisphere. The aim of this study was to determine the seasonal variation of the lipid profile in apparently healthy adults from Santiago, Chile. The study design was observational and prospective, involving 50 healthy volunteers of both genders, aged 23-62 years. The lipid profile was measured at monthly intervals over the course of one year. LDL was significantly higher in winter -spring than in summer- fall (p <0.01). Conversely, HDL decreases significantly in winter (p<0,05). We conclude that there are seasonal variations in the serum levels of LDL and HDL. The circannual pattern is characterized by increased levels of LDL in winter-spring and low levels of HDL in winter.

Reducing iron deficiency anemia in Bolivian school children: calcium and iron combined versus iron supplementation alone.

OBJECTIVE: The aim of this study was to determine the effect of combined calcium and iron versus single iron supplementation on iron status in Bolivian schoolchildren. METHODS: Children ages 6 to 10 y old (N = 195), were randomly assigned to receive either 700 mg Ca (as calcium carbonate) plus 30 mg Fe (as ferrous sulfate) (Ca + Fe group) or 30 mg Fe (as ferrous sulfate) (Fe group). The doses were administered daily, from Monday to Friday, between meals at school over 3 mo. Iron status was assessed at baseline and after intervention. Additionally, overall nutritional status was assessed by anthropometry and an estimation of dietary intake. RESULTS: At baseline, the prevalence of anemia in the Ca + Fe group and the Fe group were 15% and 21.5%, respectively. After 3 mo follow-up, the prevalence of iron deficiency anemia dropped significantly (P < 0.001) to 3% in both groups (χ(2) = NS). Iron dietary intake was within recommended levels, but calcium intake only covered 39% of the Recommended Daily Intake. CONCLUSION: Combined calcium and iron supplementation is equally as effective as single iron supplementation in reducing the prevalence of iron deficiency anemia in Bolivian school children.

Prevalencia de deficiencia y consumo de hierro, zinc y cobre en mujeres chilenas en edad fértil / Prevalence of deficiency and dietary intake of iron, zinc and copper in Chilean childbearing age women

El objetivo del presente estudio es evaluar el estado nutricional e ingesta de hierro (Fe), zinc (Zn) y cobre (Cu) en mujeres chilenas en edad fértil. Se estudió una muestra de conveniencia de 86 mujeres entre 18 a 48 años de edad de la ciudad de Santiago, Chile. El estado nutricional de Fe se determinó a través de hemoglobina (Hb), volumen corpuscular medio, saturación de transferrina, zinc protoporfirina, ferritina sérica (FS), Zn y Cu séricos. La ingesta dietética fue evaluada con una encuesta de frecuencia de consumo. Un 4,7% de las mujeres presentó anemia por deficiencia de Fe, 21% deficiencia de Fe sin anemia, 26% depósitos depletados de Fe y un 48,3% estado nutricional normal de Fe. Las mujeres obesas presentaron mayores niveles de FS (p<0,01) al comparar con mujeres con peso normal. Además, presentaron niveles más altos de Hb (p<0,05) al comparar con mujeres con estado nutricional normal y sobrepeso. El 3,5% y 2,3% de las mujeres presentó deficiencia de Zn y Cu, respectivamente. El 95%, 94% y 99% cumplió el EAR para Fe, Zn y Cu, respectivamente. No se encontraron diferencias significativas en la ingesta de micronutrientes entre las mujeres al comparar por estado nutricional. En conclusión, un alto porcentaje de las mujeres presentó una ingesta adecuada de micronutrientes. Además existe una baja prevalencia de deficiencia de Zn, Cu y anemia. Sin embargo, un 47% presenta deficiencia de Fe en etapas anteriores a la de anemia.

The aim of the present study was to evaluate anemia, the biochemical status and dietary adequacy of iron (Fe), zinc (Zn) and copper (Cu), in Chilean childbearing age women. We studied a convenience sample of 86 women aged 18 to 48 years from Santiago, Chile. We determined anemia and the micronutrient status through hemoglobin (Hb) mean corpuscular volume, transferrin saturation, zinc protoporphyrin, serum ferritin (SF), serum Zn and Cu. Dietary adequacy was estimated using a food frequency questionnaire. Of all women, 4.7% had Fe deficiency (ID) anemia, 21 % ID without anemia, 26 % depleted Fe stores and 48.3% normal Fe status. Obese women had higher SF (p<0.01) compared with those classified as having normal BMI. Also, showed higher Hb (p<0.05) concentrations compared with overweight and normal weight women. Participants showed 3.5 % and 2.3 % of Zn and Cu deficiency, respectively. Also, 95 %, 94 % and 99 % had adequate intake of Fe, Zn and Cu respectively, according to EAR cut points. There were no significant differences in micronutrients intake across different nutritional status. There was a low prevalence of anemia, Fe, Zn and Cu deficiency. A high percentage of women reached micronutrient adequacy. However, 47% of women had ID without anemia and Fe depleted stores.

One-month of calcium supplementation does not affect iron bioavailability: a randomized controlled trial.

OBJECTIVES: Calcium (Ca) and iron (Fe) are essential minerals for normal growth and development. Although previous studies have shown that Ca inhibits acute Fe absorption, there is no evidence of the possible long- or medium-term effects of Ca supplementation on Fe bioavailability. The aim of this study was to determine the effect of 34 d of Ca supplementation on heme Fe and non-heme Fe bioavailability in non-pregnant women of ages 33 to 47 y. METHODS: This was a prospective, randomized, double-blind, placebo-controlled trial. Twenty-six healthy women (40 ± 5 y) were randomly assigned to receive either 600 mg of elemental Ca/d as CaCO3 (Ca group, n = 13) or a placebo (P group, n = 13) for 34 d. Heme Fe and non-heme Fe bioavailability were determined before and after treatment using (55)Fe and (59)Fe radioisotopes. A two-factor, repeated-measures analysis of variance was used to assess differences by treatment and timing. RESULTS: The geometric mean (range ± 1 SD) of heme Fe bioavailability before and after treatment was 16.5% (8.3-32.8) and 26% (15.5-43.6) for the Ca group and 21.8% (13.0-36.6) and 25.1% (16.5-38.3) for the P group. Non-heme Fe bioavailability before and after treatment was 39.5% (19.9-78.7) and 34.1% (19.1-60.6) for the Ca group, and 44.6% (24.9-79.7) and 39.3% (24.3-63.4) for the P group. There were no differences in either heme Fe or non-heme Fe bioavailability either at baseline or after treatment. CONCLUSION: The administration of calcium supplements for 34 d does not affect iron bioavailability. This trial is registered with Controlled-trials.gov, number ISRCTN 89888123.

[Prevalence of deficiency and dietary intake of iron, zinc and copper in Chilean childbearing age women]. / Prevalencia de deficiencia y consumo de hierro, zinc y cobre en mujeres chilenas en edad fertil.

The aim of the present study was to evaluate anemia, the biochemical status and dietary adequacy of iron (Fe), zinc (Zn) and copper (Cu), in Chilean childbearing age women. We studied a convenience sample of 86 women aged 18 to 48 years from Santiago, Chile. We determined anemia and the micronutrient status through hemoglobin (Hb) mean corpuscular volume, transferrin saturation, zinc protoporphyrin, serum ferritin (SF), serum Zn and Cu. Dietary adequacy was estimated using a food frequency questionnaire. Of all women, 4.7% had Fe deficiency (ID) anemia, 21 % ID without anemia, 26 % depleted Fe stores and 48.3% normal Fe status. Obese women had higher SF (p<0.01) compared with those classified as having normal BMI. Also, showed higher Hb (p<0.05) concentrations compared with overweight and normal weight women. Partidipants showed 3.5 % and 2.3 % of Zn and Cu deficiency, respectively. Also, 95 %, 94 % and 99 % had adequate intake of Fe, Zn and Cu respectively, according to EAR cut points. There were no significant differences in micronutrients intake across different nutritional status. There was a low prevalence of anemia, Fe, Zn and Cu deficiency. A high percentage of women reached micronutrient adequacy. However, 47% of women had ID without anemia and Fe depleted stores.

Low prevalence of iron deficiency anemia between 1981 and 2010 in Chilean women of childbearing age / Baja prevalencia de anemia por deficiencia de hierro entre 1981 y 2010 en mujeres chilenas en edad fértil

Objective. To determine the prevalence of anemia and iron status among Chilean women of childbearing age between 1981 and 2010. Materials and methods. Calculation of the prevalence of anemia and iron status was based on multiple cross-sectional iron absorption studies performed in 888 women during this period of time. All studies included measurements of hemoglobin, mean corpuscular volume, zinc protoporphyrin, percentage of transferrin saturation and serum ferritin. Data were grouped by decade (1981-1990, 1991-2000, and 2001-2010). Results. Prevalence of anemia for these decades was 9, 6 and 10%, respectively (p=NS). Iron deficiency anemia was the main cause of anemia in all periods (55, 85 and 75%, respectively; p=NS). A high prevalence of women with normal iron status was observed for all periods (64, 69, and 67, respectively; p=NS). Prevalence of iron deficiency without anemia in 1981-1990, 1991-2000 and 2001-2010 was 7, 20 and 12%, respectively (p<0.05). Finally, prevalence of iron depleted stores was 20, 6 and 10%, respectively (p<0.05). Conclusions. Prevalence of iron deficiency anemia in Chilean women of childbearing age was mild between 1981 and 2010. More than 60% of childbearing age women presented normal iron status in all periods. However, prevalence of iron depleted stores was moderate during 1981-1990, and was mild during 1991-2000 and 2001-2010.

Objetivo. Determinar la prevalencia de anemia y el estado de nutrición de hierro entre 1981 y 2010 en mujeres chilenas en edad fértil. Material y métodos. La prevalencia de anemia y el estado de nutrición de hierro fueron calculados con base en múltiples estudios transversales de absorción de hierro realizados en 888 mujeres. Estos estudios incluían medición de hemoglobina, volumen corpuscular medio, zinc protoporfirina, porcentaje de saturación de transferrina y ferritina sérica. Los datos fueron agrupados por décadas (1981-1990, 1991-2000, y 2001-2010). Resultados. La prevalencia de anemia para estas décadas fue de 9, 6 y 10%, respectivamente (p=NS). La anemia por deficiencia de hierro fue la principal causa de anemia en los periodos evaluados (55, 85 y 75%, respectivamente; p=NS). Una alta prevalencia de mujeres con estado de nutrición normal de hierro fue observado en todos los periodos (64, 69, y 67%, respectivamente; p=NS). La prevalencia de deficiencia de hierro sin anemia fue de 7, 20 y 12%, respectivamente (p<0.05). Finalmente, la prevalencia de depleción de depósitos de hierro fue de 20, 6 y 10%, respectivamente (p<0.05). Conclusiones. La prevalencia de anemia por deficiencia de hierro en mujeres chilenas en edad fértil clasifica como leve entre 1981 y 2010. Más de 60% de las mujeres en edad fértil presentó estado nutricional normal de hierro en todos los periodos. Sin embargo, la depleción de depósitos de hierro fue moderada durante 1981-1990, y fue leve durante 1991-2000 y 2001-2010.

Is a 40 % absorption of iron from a ferrous ascorbate reference dose appropriate to assess iron absorption independent of iron status?

Although a 40 % absorption of a standard reference dose corresponds to iron (Fe) absorption in borderline Fe-deficient subjects, this percentage is currently applied to all subjects independent of Fe status: (a) to assess the use of the 40 % of Fe absorption of the reference dose (FeRD%) for subjects with iron-depleted stores (IDS), normal Fe status (NIS), Fe deficiency without anemia (IDWA), and Fe deficiency anemia (IDA) and (b) to explore relationships between Fe status biomarkers and FeRD%. Six hundred forty-six participants (582 women and 64 men) were selected from multiple Fe bioavailability studies and classified into four groups based on Fe status: NIS, IDS, IDWA, and IDA. All men were classified as normal. The absorption from FeRD% was calculated in each group and correlated with Fe status biomarkers. (a) Women with IDS absorbed 40 (18.9-84.7) % of the reference dose; (b) for male subjects with NIS, the absorption of the reference dose was 19 (9.8-36.1) %, while for females, absorption was observed as to be 34 (16.7-68.6)%. In the case of subjects with IDWA, a 43 (19.7-92.5) % absorption was observed, while subjects with IDA demonstrated 67 (45.2-98.6) % absorption. Serum ferritin (SF) had the strongest inverse correlation with FeRD% (r = -0.41, p < 0.001). A transferrin saturation (TS) <15 % increases the probability that the FeRD% will be highly elevated (OR, 5.05; 95 % CI, 2.73, 9.31; p < 0.001). A 40 % absorption as reference dose is only appropriate to assess Fe absorption in subjects with IDS and IDWA. SF had an inverse correlation with FeRD%, and TS increases the probability that the FeRD% will be elevated by over fivefold.