Interaction of Iron Homeostasis and Fatty Acid Metabolism in the Development of Glucose Intolerance in Women with Previous Gestational Diabetes Mellitus.

A gestational diabetes mellitus (GDM) diagnosis during pregnancy means an increased risk of developing type 2 diabetes later in life. By following up with women after GDM we aimed to examine the relationship between iron parameters, individual fatty acids (FAs) and desaturases in the development of impaired glucose metabolism (IGM). Based on an oral glucose tolerance test (OGTT), six years after GDM, 157 women were grouped as having normal glucose tolerance (NGT) or IGM. Fasting serum FAs, activity of desaturases and iron parameters (ferritin, transferrin, iron, soluble transferrin receptor, total iron binding capacity, hepcidin) were measured, and clinical and anthropometric measurements taken. Soluble transferrin receptor was higher in the IGM group compared to the NGT group (3.87 vs. 3.29 mg/L, p-value = 0.023) and associated positively with saturated FAs and negatively with monounsaturated FAs in the IGM group (adjusted for BMI, age and high sensitivity C-reactive protein; p-value < 0.05). Iron, as well as transferrin saturation, showed a positive association with MUFAs and desaturase activity. These associations were not seen in the NGT group. These results suggest that iron homeostasis and FA metabolism interact in the development of glucose intolerance in women with previous GDM.

Lower Non-Heme Iron Absorption in Healthy Females from Single Meals with Texturized Fava Bean Protein Compared to Beef and Cod Protein Meals: Two Single-Blinded Randomized Trials.

Meat analogs based on plant protein extracts are rising in popularity as meat consumption declines. A dietary shift away from meat, which has a high iron bioavailability, may have a negative effect on the amount of iron absorbed from the diet. Iron absorption from legumes cultivated in regions not suitable for soy production, such as fava bean, has not yet been explored. The aim of this study was to evaluate non-heme iron absorption from a meal with texturized fava bean protein compared to beef and cod protein meals. The study included two single-blinded iron isotope trials in healthy Swedish women of the ages 18-45 years, each of whom served as their own control. The participants were served matched test meals containing beef and fava bean protein (Study 1) or cod and fava bean protein (Study 2) with radiolabeled non-heme iron 55Fe and 59Fe. The absorption of non-heme iron from test meals was measured by whole-body counting and erythrocyte incorporation. The absorption of non-heme iron, measured as erythrocyte incorporation ratio, from beef protein meal was 4.2 times higher compared to texturized fava bean meal, and absorption from cod protein meal was 2.7 times higher compared to the fava bean meal. The adjusted non-heme iron absorption, normalized to a 40% reference dose uptake, was 9.2% for cod protein meal, 21.7% for beef protein meal, and 4.2% for texturized fava bean meal. A fava bean protein meal has markedly lower iron bioavailability in healthy females compared with a meal of beef or cod protein. Therefore, a dietary shift from meat and fish protein to fava bean protein may increase the risk of iron deficiency.

The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial.

INTRODUCTION: Iron deficiency during pregnancy is a global health problem and is associated with adverse pregnancy outcomes. The aim of this randomized, double-blind, placebo-controlled study was to evaluate the effect of Lactiplantibacillus plantarum 299v (Lp299v, 1010 colony forming units), 4.2 mg iron, 12 mg ascorbic acid and 30 µg folic acid (Lp) on iron status in healthy, non-anemic, pregnant Swedish women. MATERIAL AND METHODS: A total of 326 women were randomized to receive Lp (n = 161) or placebo (n = 165) twice daily from gestational week 10-12 until end of pregnancy or until the potential start of iron therapy. The primary endpoint was serum ferritin at week 28. RESULTS: Intake of Lp attenuated the decrease in serum ferritin from baseline to week 28 (p = 0.003) and week 35 (p Ë‚ 0.001) and resulted in reduced prevalence of iron deficiency (59% vs 78%, p = 0.017) and iron deficiency anemia (7.4% vs 21%, p = 0.023) at week 35. Intake of Lp also resulted in beneficial effects on the soluble transferrin receptor (p = 0.011) and total body iron (p Ë‚ 0.001) at week 35. Gestational length and birthweight were comparable between groups. The proportion of women reporting adverse events during the study was comparable between groups. CONCLUSIONS: Intake of Lp from early pregnancy was safe, attenuated the loss of iron stores and improved iron status in healthy pregnant women.

Correction to: Low-phytate wholegrain bread instead of high-phytate wholegrain bread in a total diet context did not improve iron status of healthy Swedish females: a 12 week, randomized, parallel-design intervention study.

ue to author error the paper was published wit.

Low-phytate wholegrain bread instead of high-phytate wholegrain bread in a total diet context did not improve iron status of healthy Swedish females: a 12-week, randomized, parallel-design intervention study.

PURPOSE: To investigate the effects of eating wholegrain rye bread with high or low amounts of phytate on iron status in women under free-living conditions. METHODS: In this 12-week, randomized, parallel-design intervention study, 102 females were allocated into two groups, a high-phytate-bread group or a low-phytate-bread group. These two groups were administered: 200 g of blanched wholegrain rye bread/day, or 200 g dephytinized wholegrain rye bread/day. The bread was administered in addition to their habitual daily diet. Iron status biomarkers and plasma alkylresorcinols were analyzed at baseline and post-intervention. RESULTS: Fifty-five females completed the study. There was a significant difference in change over time in total body iron stores between the two groups (p < 0.035). In the low-phytate bread group (n = 24) there were significant within-group decreases in both ferritin (mean 12%; from 32 ± 7 to 27 ± 6 µg/L, geometric mean ± SEM, p < 0.018) and total body iron (mean 12%; from 6.9 ± 1.4 to 5.4 ± 1.1 mg/kg, p < 0.035). Plasma alkylresorcinols indicated that most subjects complied with the intervention CONCLUSIONS: In Swedish females of reproductive age, no statistically significant difference in iron status was detected after 12 weeks of high-phytate wholegrain bread consumption. However, consumption of low-phytate wholegrain bread for 12 weeks resulted in a reduction of markers of iron status. Although single-meal studies clearly show an increase in iron bioavailability from dephytinization of cereals, medium-term consumption of reduced phytate bread under free-living conditions suggests that this strategy does not work to improve iron status in healthy women of reproductive age.

Is cord blood hepcidin influenced by the low-grade acute-phase response occurring during delivery? A small-scale longitudinal study.

AIM: To measure serum hepcidin in late pregnancy and in cord blood, and to analyze relationship between hepcidin, interleukin-6, and biomarkers of fetal iron status. MATERIALS AND METHODS: Data from 15 uncomplicated singleton pregnancies were analyzed longitudinally in trimester 3 (T3) and at birth. RESULTS: In T3, S-ferritin (median 14 µg/L) and transferrin (median 4.0 g/L) indicated low iron status, whereas the median soluble transferrin receptor (sTfR) was 4.0 mg/L, i.e. within the reference interval. Median T3 S-hepcidin was 7.8 ng/mL. Later on in cord blood, ferritin concentration (180 µg/L) were significantly higher, transferrin concentration (1.8 g/L) were significantly lower, and both sTfR (4.7 mg/L) and S-hepcidin concentrations (30.5 ng/mL) were significantly higher than maternal T3 concentrations. At the same time, cord blood interleukin-6 indicated an activated acute-phase reaction. In T3, after logarithmic transformation, there was a significant correlation between S-hepcidin and both S-ferritin (r = 0.691) and sTfR (r = -0.825). There was also a significant correlation between S-ferritin and both sTfR (r = -0.729) and transferrin (r = 0.549) in T3. CONCLUSIONS: Although S-ferritin, S-hepcidin, and sTfR were correlated during pregnancy, these relationships were not apparent in umbilical cord blood. Further, cord blood interleukin-6 indicated an activated acute-phase response, and sTfR, which is known to be unaffected by inflammation, indicated a low iron status in cord blood. Thus, instead of representing an enhanced iron status, the data appear to suggest that hepcidin and ferritin in cord blood may be influenced by the low-grade acute-phase response that occurs during delivery.

Iodine Status After Bariatric Surgery-a Prospective 10-Year Report from the Swedish Obese Subjects (SOS) Study.

CONTEXT: Bariatric surgery can lead to nutrient deficiencies. Gastric by-pass (GBP) entails restriction and malabsorption, whereas, vertical banded gastroplasty (VBG) is only restrictive. OBJECTIVE: The objective of this study is to study whether GBP-patients develop iodine deficiency from malabsorption, and if GBP- and VBG-patients develop lower 24-h urinary iodine excretion (24-UIE) than obese non-operated controls (OB-controls) due to lower iodine intake. DESIGN: The Swedish Obese Subjects (SOS) study is a prospective, non-randomized study of 4047 obese patients included 1987-2001, who chose bariatric surgery or non-surgical treatment. SOS-groups were compared at baseline, after 2 and 10 years and with population-based subsamples (MONICA-controls). PATIENTS: One hundred eighty-eight GBP-patients were matched with 188 VBG-patients and 188 OB-controls and with three subgroups from 412 MONICA-controls. MAIN OUTCOME MEASUREMENTS: Primary outcome was 24-UIE. Secondary outcomes were iodine intake, iodine supplementation, TSH, FT4, and thyroid morbidity. RESULTS: At baseline, median 24-UIE was higher in GBP-patients, VBG-patients and OB-controls than in MONICA-controls (214, 201, 203 and 137 µg/day, p < 0.001). At 10 years, 24-UIE in GBP-patients (161 µg/day) and VBG-patients (149 µg/day) was lower compared with baseline (p < 0.01) and OB-controls (189 µg/day, p < 0.01), but similar to 24-UIE in MONICA-controls (137 µg/day). The 10-year-dietary iodine intake was similar in GPB-patients and OB-controls, but higher in VBG-patients. Iodine supplementation was taken by 0-9% in SOS-groups. CONCLUSION: After surgery, GBP- and VBG-patients did not suffer from iodine deficiency, but both groups had lower iodine status than OB-controls. Dietary supplements recommended after bariatric surgery do not need to include iodine, in iodine sufficient countries. TRIAL REGISTRATION: clinicaltrials.gov : NCT01479452.

Freeze-dried Lactobacillus plantarum 299v increases iron absorption in young females-Double isotope sequential single-blind studies in menstruating women.

BACKGROUND: The probiotic strain Lactobacillus plantarum 299v has earlier been shown to increase iron absorption when added to foods. However, it is not known if the same probiotic strain in a freeze-dried format included in a capsule increases the iron absorption. OBJECTIVE: The aim of this study was to test the hypotheses that non-heme iron absorption from a light meal is promoted by a simultaneous intake of freeze-dried Lactobacillus plantarum 299v (Lp299v, DSM 9843). STUDY DESIGN: With a single blinded placebo controlled sequential design, iron absorption from a light breakfast meal administered with or without capsules containing 1010 cfu freeze-dried Lp299v was studied in healthy female volunteers of fertile age. The methodology used was a double isotope technique (59Fe and 55Fe). Two studies were performed using the same protocol. RESULTS: In study 1, the absorption of iron from a meal without Lp299v was found to be 17.4 ± 13.4%, and from an identical meal with Lp299v was found to be 22.4 ± 17.3% (mean ± SD). This difference was statistically significant (p = 0.040, n = 14). In study 2, the absorption of iron from a meal without Lp299v was found to be 20.9 ± 13.1%, and from an identical meal with Lp299v found to be 24.5 ± 12.0% (mean ± SD, n = 28), which again was statistically significant (p = 0.003). CONCLUSION: Freeze-dried Lp299v enhances the absorption of iron when administered together with a meal with a high iron bioavailability. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02131870.

Increased iron bioavailability from lactic-fermented vegetables is likely an effect of promoting the formation of ferric iron (Fe(3+)).

BACKGROUND: Lactic fermentation of foods increases the availability of iron as shown in a number of studies throughout the years. Several explanations have been provided such as decreased content of inhibitory phytate, increased solubility of iron, and increased content of lactic acid in the fermented product. However, to our knowledge, there are no data to support that the bioavailability of iron is affected by lactic fermentation. OBJECTIVES: The objective of the present study was to investigate whether the bioavailability of iron from a vegetable mix was affected by lactic fermentation and to propose a mechanism for such an event, by conducting human and cell (Caco-2, HepG2) studies and iron speciation measurements (voltammetry). We also investigated whether the absorption of zinc was affected by the lactic fermentation. RESULTS: In human subjects, we observed that lactic-fermented vegetables served with both a high-phytate and low-phytate meal increased the absorption of iron, but not zinc. In vitro digested fermented vegetables were able to provoke a greater hepcidin response per ng Fe than fresh vegetables, indicating that Fe in the fermented mixes was more bioavailable, independent on the soluble Fe content. We measured that hydrated Fe(3+) species were increased after the lactic fermentation, while there was no significant change in hydrated Fe(2+). Furthermore, lactate addition to Caco-2 cells did not affect ferritin formation in response to Fe nor did lactate affect the hepcidin response in the Caco-2/HepG2 cell system. CONCLUSIONS: The mechanism for the increased bioavailability of iron from lactic-fermented vegetables is likely an effect of the increase in ferric iron (Fe(3+)) species caused by the lactic fermentation. No effect on zinc bioavailability was observed.

Dietary intake, resting energy expenditure, and eating behavior in women with and without polycystic ovary syndrome.

BACKGROUND: Data on dietary intake, meal patterns, and eating attitudes from women with polycystic ovary syndrome (PCOS) is limited despite the fact that PCOS is associated with obesity. We aimed to test the hypothesis that women with PCOS display altered dietary intakes and eating behaviors compared to controls. METHODS: Women with PCOS (n = 72) as defined according to the modified Rotterdam criteria were compared with healthy controls (n = 30). Anthropometry included measurement of waist circumference and determination of the resting metabolic rate via indirect calorimetry. All women completed questionnaires regarding eating behavior; Three-Factor Eating Questionnaire (TFEQ-R21) and eating attitudes; Eating Attitudes Test (EAT). Group comparisons were done by Mann-Whitney U test and logistic regression analysis was used for adjustments of age and BMI in a non-parametric way. RESULTS: BMI was higher in women with PCOS compared to controls. Resting metabolic rate did not differ between women with women with and without PCOS after adjustment for age and BMI [1411 ± 229 kcal/day versus 1325 ± 193 kcal per day (P = 0.07)], whereas the respiratory exchange ratio was higher in women with PCOS than in controls [0.83 ± 0.07 versus 0.78 ± 0.08 (P = 0.02 after adjustments for age and BMI)]. Energy percent (E%) carbohydrates was higher in women with PCOS compared to controls (P = 0.017), but E% alcohol was lower (P = 0.036) after adjustment for age and BMI. The average total EAT scores and EAT dieting subscale scores were higher in women with PCOS compared with controls (P = 0.001 and P = 0.024, respectively) after adjustment for age and BMI. No difference was found for previous or current symptoms of bulimia nervosa. CONCLUSIONS: Independent of BMI and age, the resting metabolic rate did not differ between women with and without PCOS indicating that women with PCOS should have equal abilities in terms of energy metabolism to lose weight as women without PCOS. Women with PCOS showed greater concerns about their weight and dieting, and this indicates that anxiety about weight is one of the psychological symptoms of PCOS.

Probiotic strain Lactobacillus plantarum 299v increases iron absorption from an iron-supplemented fruit drink: a double-isotope cross-over single-blind study in women of reproductive age.

Iron deficiency is common, especially among young women. Adding probiotics to foods could be one way to increase iron absorption. The aim of this study was to test the hypothesis that non-haem iron absorption from a fruit drink is improved by adding Lactobacillus plantarum 299v (Lp299v). Iron absorption was studied in healthy women of reproductive age using a single-blind cross-over design in two trials applying the double-isotope (55Fe and 59Fe) technique. In Trial 1, iron absorption from a fruit drink containing 109 colony-forming units (CFU) Lp299v was compared with that from a control drink without Lp299v. Trial 2 had the same design but 1010 CFU were used. The test and control drinks contained approximately 5 mg of iron as ferrous lactate and were labelled with 59Fe (B) and 55Fe (A), respectively, and consumed on 4 consecutive days in the order AABB. Retention of the isotopes was measured with whole-body counting and in blood. Mean iron absorption from the drink containing 109 CFU Lp299v (28·6(sd 12·5) %) was significantly higher than from the control drink (18·5(sd 5·8) %), n 10, P<0·028). The fruit drink with 1010 CFU Lp299v gave a mean iron absorption of 29·1(sd 17·0) %, whereas the control drink gave an absorption of (20·1(sd 6·4) %) (n 11, P<0·080). The difference in iron absorption between the 109 CFU Lp299v and the 1010 CFU Lp299v drinks was not significant (P=0·941). In conclusion, intake of probiotics can increase iron absorption by approximately 50 % from a fruit drink having an already relatively high iron bioavailability.

Heme iron-based dietary intervention for improvement of iron status in young women.

OBJECTIVE: Conventional iron deficiency treatment with pharmacologic iron doses often causes side effects. Heme iron has high bioavailability and a low capacity to cause gastrointestinal side effects. This study investigated the possibility of using heme iron in the form of blood-based crisp bread as a diet-based treatment program to improve the iron status of women of reproductive age. METHODS: In a 12-wk intervention study, 77 women (mean age 24 y) were assigned to one of four groups: blood-based crisp bread (35 mg of iron [Fe], 27 mg of which was heme Fe), iron supplementation consisting of 35 mg of non-heme iron/day (Fe35), iron supplementation consisting of 60 mg of non-heme iron/day (Fe60), and controls (iron-free tablets). RESULTS: Body iron increased significantly in the crisp bread group by a median of 2.7 mg/kg (interquartile range 3.1, n = 18), in the Fe35 group by 2.7 mg/kg (interquartile range 2.8, n = 11), and in the Fe60 group by 4.1 mg/kg (interquartile range 3.6, n = 13), whereas no change was observed in the control group. No statistically significant difference in iron status increase was observed between the crisp bread group compared with the two iron-supplemented groups. CONCLUSION: Dietary-based treatment containing heme iron has few side effects and can be used efficiently to improve the iron status of women of reproductive age.

Revised recommendations for iron fortification of wheat flour and an evaluation of the expected impact of current national wheat flour fortification programs.

BACKGROUND: Iron fortification of wheat flour is widely used as a strategy to combat iron deficiency. OBJECTIVE: To review recent efficacy studies and update the guidelines for the iron fortification of wheat flour. METHODS: Efficacy studies with a variety of iron-fortified foods were reviewed to determine the minimum daily amounts of additional iron that have been shown to meaningfully improve iron status in children, adolescents, and women of reproductive age. Recommendations were computed by determining the fortification levels needed to provide these additional quantities of iron each day in three different wheat flour consumption patterns. Current wheat flour iron fortification programs in 78 countries were evaluated. RESULTS: When average daily consumption of low-extraction (< or = 0.8% ash) wheat flour is 150 to 300 g, it is recommended to add 20 ppm iron as NaFeEDTA, or 30 ppm as dried ferrous sulfate or ferrous fumarate. If sensory changes or cost limits the use of these compounds, electrolytic iron at 60 ppm is the second choice. Corresponding fortification levels were calculated for wheat flour intakes of < 150 g/day and > 300 g/day. Electrolytic iron is not recommended for flour intakes of < 150 g/day. Encapsulated ferrous sulfate or fumarate can be added at the same concentrations as the non-encapsulated compounds. For high-extraction wheat flour (> 0.8% ash), NaFeEDTA is the only iron compound recommended. Only nine national programs (Argentina, Chile, Egypt, Iran, Jordan, Lebanon, Syria, Turkmenistan, and Uruguay) were judged likely to have a significant positive impact on iron status if coverage is optimized. Most countries use non-recommended, low-bioavailability, atomized, reduced or hydrogen-reduced iron powders. CONCLUSION: Most current iron fortification programs are likely to be ineffective. Legislation needs updating in many countries so that flour is fortified with adequate levels of the recommended iron compounds.

Free-living energy expenditure in children using multi-sensor activity monitors.

AIMS: To improve the energy expenditure algorithm of the activity monitor ActiReg, and to validate ActiReg and the activity monitor SenseWear in free-living children. METHODS: The development of the ActiReg algorithm was performed in 20 healthy 11-13 years old children on treadmill walking and running with indirect calorimetry as reference. The original and new ActiReg algorithms and SenseWear using software versions InnerView 5.1 and 6.1 were validated in 20 healthy 14-15 years old children against doubly labelled water. RESULTS: The new ActiReg algorithm improved the assessment of energy expenditure during walking and running, but the response from the monitor levelled off after 7 km h(-1). The new algorithm and InnerView 6.1 decreased the mean (sd) difference to doubly labelled water from 11 (25) (P<0.05) to 0 (22) kJ kg(-1) d(-1) for ActiReg, and from 17 (20) (P<0.01) to -10 (21) (P<0.05) kJ kg(-1) d(-1) for SenseWear. However, the correlations between energy expenditure and the individual error for the new ActiReg algorithm and InnerView 6.1 were r= -0.50 (P<0.05) and r= -0.73 (P<0.01). CONCLUSIONS: The new ActiReg algorithm and InnerView 6.1 improved the activity monitors at group level, but the error was dependent on physical activity level. Both activity monitors need further developments for use in children.

Hepcidin, interleukin-6 and hematological iron markers in males before and after heart surgery.

Anemia of inflammation in patients with acute or chronic acute-phase activation is a common clinical problem. Hepcidin is a peptide shown to be the principal regulator of the absorption and systemic distribution of iron. Main inducers of hepcidin are iron overload, hypoxia and inflammation, where the latter has been linked to hepcidin via increased interleukin-6 (IL-6). This article addresses the impact and time course of postoperative acute-phase reaction in humans following heart surgery on prohepcidin, hepcidin, hematological markers and IL-6 concentrations. Serum concentrations of prohepcidin, hepcidin, IL-6 and hematological iron parameters were studied in five male patients without infection before and after heart surgery. This study, which is the first to report the impact on serum hepcidin and serum prohepcidin concentrations in patients following surgery, clearly demonstrates the induction of hypoferremia due to the postoperative acute-phase reaction. Significant changes were seen for serum iron concentration, transferrin saturation, total iron binding capacity and hemoglobin concentration. A significant increase in ferritin concentration was seen 96-144 h postoperatively. Additionally, there were significant alterations in both serum hepcidin after 96-144 h and serum prohepcidin after 48 h compared with preoperative values. Serum prohepcidin decreased, whereas serum hepcidin increased. In conclusion, changes in serum prohepcidin were followed by an increase in serum hepcidin. This speaks in favor of a chain of action where proteolytic trimming of serum prohepcidin results in increased serum hepcidin. However, hypoferremia appeared prior to the changes in serum prohepcidin and serum hepcidin.

Weight and length at birth and their relationship to diabetes incidence and all-cause mortality--a 32-year follow-up of the population study of women in Gothenburg, Sweden.

OBJECTIVE: The purpose of the study was to explore the relationship of weight and length at birth to diabetes in adult life and to all-cause mortality. Special attention was taken to potential confounding factors as age, family history, education, socio-economic group, physical inactivity, smoking, blood pressure, serum lipids and obesity. RESEARCH DESIGN AND METHODS: A longitudinal population study consisting of a representative sample of 1381 women aged 38-54 started in Gothenburg, Sweden, in 1968-1969 monitoring for diabetes mellitus and overall mortality over 32 years. Original delivery records were retrieved for 61.2% of the women. Death certificates were obtained for 99.3% the women who died during the 32-year follow-up period. RESULTS: We observed an inverse statistically significant relationship between birth weight and 32-year diabetes incidence independent of age, the highest incidence 16.3% in the lowest quartile of birth weight compared to 9.2% in the highest quartile. The relationship remained when controlling for the following covariates: education, socio-economic group, physical activity, smoking, systolic blood pressure, adult body mass index (BMI), waist-hip ratio, serum triglycerides and cholesterol. When overweight women (BMI> or =25) were excluded from the statistical analyses birth weight was even stronger related to the incidence of diabetes, 12.8% in lowest quartile and 5.7% in the highest quartile of birth weight independent of birth length, education, socio-economic group, physical activity, smoking, systolic blood pressure, body mass index, waist-hip ratio, blood glucose, serum triglycerides and cholesterol. Length at birth was a predictor for diabetes independent of age plus adult body mass index (BMI) and smoking but not independent of age only. No significant associations were observed between birth factors as birth weight and birth length and overall mortality during the 32-year of follow-up. CONCLUSIONS: A low birth weight seems to be a risk factor for diabetes in adult women independent of age and most of the established risk factors for diabetes.

Iron status in Swedish teenage girls: impact of low dietary iron bioavailability.

OBJECTIVE: Although it is well known that bioavailability of iron in the diet is important, it has not been fully elucidated in practice. We investigated iron intake and iron absorption in the ordinary diet of free-living individuals in relation to iron status and assessed iron requirements. METHODS: From a total of 1245 adolescent boys and girls included in the Göteborg Adolescence Study of food habits, 28 adolescent girls registered their food intake during 7 d. Iron intake was assessed on the basis of these 7-d dietary records. Iron absorption was calculated using an algorithm including enhancing and inhibiting dietary factors on iron absorption in relation to individual iron status. RESULTS: Available iron intake was 11.5 +/- 2.8 mg/d (mean +/- SD). The proportion of girls with an iron intake below the Nordic nutrition recommendations was 85% (n = 24). Calculated iron absorption was 1.09 +/- 0.59 mg/d (mean +/- SD). Only four girls satisfied their estimated individual iron requirement concerning the absorbed amount of iron. Iron depletion (serum ferritin concentration < or = 15 microg/L) was present in 10 girls (36%), 2 of whom were also anemic (hemoglobin concentration < or = 120 g/L). CONCLUSION: Swedish adolescent girls seemed to have difficulties satisfying their iron requirement in terms of absorbed amount. The data support the view that iron intake and bioavailability of dietary iron is important when evaluating whether iron requirements have been met.