Dietary Iron Bioavailability: Agreement between Estimation Methods and Association with Serum Ferritin Concentrations in Women of Childbearing Age

Potentials and limitations of a food group-based algorithm to assess dietary nutrient intake of women in rural areas in Tanzania

The aim of this study was to evaluate the accuracy of nutrient intake assessment with the food group-based algorithm "Calculator of Inadequate Micronutrient Intake" (CIMI) in comparison to the established nutrition software NutriSurvey. Using Food Frequency Questionnaires and 24-h dietary recalls of 1010 women from two rural districts in Tanzania, 23 relevant typical Tanzanian food groups were identified and subsequently the dietary protocols assessed via CIMI algorithm were compared by bivariate correlations and Bland-Altman analysis with the results of the NutriSurvey software (reference) and were set in relation to blood biomarkers of 666 participants. CIMI and NutriSurvey calculations regarding macro- and micronutrient intakes were similar. The Bland-Altman analyses and correlation coefficients of energy (0.931), protein (0.898), iron (0.775) and zinc (0.838) confirm the agreement of both calculations. The food group based CIMI algorithm is a practical tool to identify the inadequacy of macro- and micronutrient intake at population level.

Adherence to Iron and Folic Acid Supplementation Among Pregnant Women From Northern Ghana

Iron and folic Acid (IFA) supplementation is an effective intervention for reducing the incidence of anaemia during pregnancy. The WHO recommends at least 6 months intake of IFA to pregnant women. However, in Ghana some women experience challenges with adhering to IFA supplementation. The main objective of the study was to assess the level of adherence to iron and folic acid supplementation and its associated factors among pregnant women in a peri-urban municipality in Northern Ghana. A cross-sectional study was conducted from March to December 2021 among 400 pregnant women who attended ANC in Sagnarigu municipality in Ghana and were selected through a 3-stage random sampling technique. A structured questionnaire was used to collect data. The data were analysed using descriptive statistics, univariate and binary logistic regression statistical tools. Self-reported level of adherence to iron and folic acid supplementation was 84.5%. Knowledge of iron and folic acid supplementation (AOR = 0.08: 021, 0.343) was associated with adherence. Three other factors: time of first antenatal visit (AOR = 0.32: 0.153, 0.649) having history of anaemia [AOR = 2.67: 1.373, 5.201] having side effects of IFA [AOR = 3.70, CI: (1.756, 7.793)], and having knowledge of management of side effects of iron and folic acid supplementation (AOR = 0.08: 021, 0.343) were found to be significantly associated with adherence. Adherence to iron and folic supplementation among the pregnant women was generally frequent. Strategies to increase iron and folic acid supplementation adherence among pregnant women could focus on encouraging pregnant women to have early ANC visits and educating them on how to manage side effects.

Estimation of the availability of iron in the school meals of Municipal Centers for Early Childhood Education of a capital city in northeastern Brazil

The final stage of Fe deficiency is Fe deficiency anaemia, with repercussions for human health, especially in children under 5 years of age. Studies conducted in Brazilian public daycare centres show high prevalence of anaemia. The present study aims to evaluate the availability of Fe in the meals of the Municipal Centers of Early Childhood Education in Maceió. The experimental design comprises selection of algorithms, menu evaluation, calculation of the estimates, comparison between the estimates obtained and the recommendations, and analysis of correlation between meal constituents, and of the concordance between the absorbable Fe estimates. Four algorithms were selected and a monthly menu consisting of 22 d. The correlation analysis showed a moderate positive correlation to animal tissue (AT) v. non-heme iron (r = 0·42; P = 0·04), and negative to AT v. Ca (r = -0·54; P = 0·09) and Ca v. phytates (r = -0·46, P = 0·03). Estimates of absorbable Fe ranged from 0·23 to 0·44 mg/d. The amount of Fe available, unlike the total amount of Fe offered, does not meet the nutritional recommendations on most school days. The Bland-Altman analysis indicated that the Monsen and Balinfty and Rickard et al. showed greater agreement. The results confirm the need to adopt strategies to increase the availability of Fe in school meals.

Nutritional and health benefits and risks of plant-based substitute foods

Plant-based substitutes (PBS) are seen as a convenient way to transition to a more plant-based diet, but their potential health benefits and nutritional concerns remain debated. Based on a review of the literature, it is concluded here that the primary risk of insufficient nutrient intake with PBS concerns iron and calcium, which are critical to the nutritional value of PBS. Other risks were identified but these would depend on the characteristics of the overall diet, as is the case for iodine in a diet containing no seafood or dairy, and vitamin B12 in a vegetarian/vegan diet. Conversely, the use of PBS is also expected to confer some benefits for long-term health because it would result in higher fibre intakes (in the case of meat PBS) and lower SFA intakes (but higher PUFA/MUFA intakes), but attention should be paid to a potential increase in sodium intake with PBS of meat products. In fact, a recurring finding in this review was that PBS is a very heterogeneous food category involving considerable variations in ingredient and nutrient composition, and whose design could be improved in order to foster nutritional and health benefits. The latter also depend on the animal food that is being replaced and are only deemed likely when PBS replace red meat. The fortification of PBS with key nutrients such as iron and calcium may constitute an actionable public health solution to further shift the balance in favour of PBS in the context of the current dietary transition in western countries.

Dietary iron intake over two post-fortification periods in Brazil: data from the National Dietary Surveys 2008-2009 and 2017-2018

We aimed to assess the dietary Fe intake and the prevalence of inadequate Fe intake over two post-fortification periods in Brazil. The intake was analysed according to sex, life stage, geographic region and stratum of family income per capita. Excluding pregnant and lactating women, this population-based study included 32 749 and 44 744 participants aged ≥ 10 years from the National Dietary Survey-Brazilian Household Budget Surveys 2008-2009 and 2017-2018, respectively. The National Cancer Institute method was used to predict usual dietary Fe intakes. The prevalence of Fe intake inadequacy was estimated following a probabilistic approach for women of childbearing age or with the Estimated Average Requirement cut-off point method. Over an interval of 10 years, the mean Fe intake remained almost unchanged for most sex-age groups, except for women of childbearing age. In this specific group, the prevalence of Fe intake inadequacy was > 20 % in 2008-2009 and have increased to > 25 % in 2017-2018, with the highest reductions in mean Fe intake found in the highest income strata and richest Brazilian regions. Meanwhile, the highest prevalence of Fe intake inadequacy (> 40 %) occurred among the poorest women aged 31-50 years from the lowest family income stratum, irrespective of the study period. Beans were the main Fe source, while fortified breads, pastas, pizzas, cakes and cookies contributed approximately 40 % of the Fe intake. The results provide important insights into the long-standing dietary impacts of food fortification, which can guide future (re)formulation of effective public health strategies to combat Fe deficiency.

Toddlers may be getting enough iron in long day-care services after all

BACKGROUND

Previous research has suggested that toddlers are not provided with adequate dietary iron in long-day care (LDC) services. However, the iron bioavailability provided is unknown. The present study aimed to investigate the amount and bioavailability of iron provided to toddlers aged 2-3 years at LDC services.

METHODS

A cross-sectional audit was conducted using a 2-day weighed food record of 30 LDC services. Iron provision (not child intake) in LDC services across Perth, Australia was compared with the estimated average requirements (EAR) and LDC services provision guidelines (50% of EAR = 2 mg/day based on a 14% bioavailability factor). Bioavailability was estimated per mealtime using haem and non-haem iron, ascorbic acid, animal protein, calcium, soy, eggs and phytates using two pre-existing algorithms (by A. P. Rickard and colleagues and H. Hallberg and H. Hulten).

RESULTS

Median iron supplied (2.52 mg/day, interquartile range [IQR] = 2.43-3.17) was above the 50% of EAR of 2.0 mg/day (p < 0.001). Median bioavailable iron was 0.6 mg/day (IQR = 0.54-0.8) using the method of Rickard et al. and 0.51 mg/day (IQR = 0.43, 0.76 using that of Hallberg and Hulthen). The top three foods contributing to iron provision were bread, breakfast cereals and beef.

CONCLUSIONS

Our results suggest that LDC services in Perth are meeting the minimum recommendation of provision of 50% of the iron EAR, and also that toddlers are provided with sufficient bioavailable iron. Future strategies should focus on promoting food combinations to maintain the iron bioavailability in meals currently served at LDC services.

Iron Bioavailability Should be Considered when Modeling Omnivorous, Vegetarian, and Vegan Diets

BACKGROUND

To lower environmental impact of human food consumption, replacement of animal proteins with plant-based proteins is encouraged. However, the lower iron bioavailability of plant-based foods is rarely considered when designing healthy and sustainable diets by using diet modeling. The estimated absorbable iron content of vegetarian and vegan menu plans might therefore be too optimistic.

OBJECTIVE

The main aim of this study was to investigate and compare the impact of various methods to estimate absorbable iron intake on the nutritional adequacy of omnivorous, vegetarian, and vegan menu plans designed for women of reproductive age.

METHODS

A diet model was developed to design menu plans consisting of a selection of meals that best complied with nutritional requirements. Meals used for modeling were created based on food intake data from the National Health and Nutrition Examination Survey (NHANES). For each meal, absorbable iron concentrations were estimated by using 2 constant absorption factors (18% and 10%) and 2 diet-dependent absorption equations (Conway and Hallberg). For each absorption method and diet type, we used the diet model to design the optimal menu plan. Retrospectively, menu plans were evaluated by estimating the absorbable iron content by using the other absorption methods.

RESULTS

Retrospective diet-dependent absorbable iron estimates were consistently lower than estimates based on constant absorption factors. Using diet-dependent estimates increased absorbable iron by optimizing enhancer and inhibitor concentrations.

CONCLUSION

Iron bioavailability should be considered when modeling diets.

Prevalence of iron deficiency anemia in Brazilian women of childbearing age: a systematic review with meta-analysis

BACKGROUND

Iron deficiency anemia (IDA) is among the most common micronutrient deficiencies in women of childbearing age and may affect children's development. Brazil has several national programs to tackle this condition, such as food fortification and supplementation for pregnant women, but IDA prevalence in this population has not been systematically reviewed. We sought to determine the prevalence of IDA in Brazilian women of childbearing age through a systematic review with metanalysis.

METHODOLOGY

A protocol was previously published on the PROSPERO platform under the code CRD42020200960. A panel of the National Council for Scientific and Technological Development (CNPq) approved the protocol of this study under the public call number 26/2019. The main databases searched were MEDLINE, Web of Science, Scopus, Lilacs, and SciELO. In gray literature, the Brazilian Digital Library of Theses and Dissertations and the annals of the Brazilian Congress of Epidemiology and the Brazilian Congress of Public Health were accessed. The search strategy involved terms related to the condition (IDA) and the age group of the population of interest (teenagers and adults). Studies that had assessed the prevalence of IDA in Brazilian women of childbearing age (10-49 years) were included. Three independent reviewers read all titles and abstracts and extracted data from the included studies. Random effects meta-analyses using the Freeman-Tukey arcsine transformation were carried out with prevalence data, and meta-regression was conducted to test for subgroup differences. The quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

From 21,210 unique records screened, 237 full-texts were retrieved, of which 91 were included in the qualitative synthesis, and 83 were included in the meta-analysis. The overall IDA prevalence was 25% (95% CI [23-28], 83 studies). The subgroup of studies that used random sampling showed a prevalence of 22% (95% CI [17-27], 22 studies), whereas in those with non-random sampling, the prevalence was 27% (95% CI [23-30], 61 studies), without significant differences between subgroups in the metaregression (P = 0.13). High prevalence of IDA were found in the subgroups of studies conducted in the North and Northeast regions (30%; 95% CI [24-37]; seven studies, and 30%; 95% CI [26-34]; 27 studies, respectively), in studies conducted with indigenous population (53%; 95% CI [27-78], four studies), and with studies that had their collections after 2015 (28%; 95% CI [23-34], nine studies).

CONCLUSIONS

IDA in women of childbearing age remains a public health problem in Brazil, especially in the North and Northeast region. The national programs should be strengthened and more thoroughly supervised to decrease this condition nationally.

The association between the levels of anti-Müllerian hormone (AMH) and dietary intake in Iranian women

PURPOSE

This paper aimed to assess the association between AMH with dietary intake of adult women referred to the infertility clinic of Al-Zahra Hospital in Rasht, Iran.

METHODS

This cross-sectional study was performed on 234 adult women referred to the infertility clinic of Al-Zahra Hospital, Rasht, Iran. The participants were categorized into two groups based on their AMH levels. Participants' data on lifestyle and anthropometry as well as blood samples were collected. Dietary intakes were assessed by a validated food frequency questionnaire (FFQ).

RESULTS

Serum AMH concentration was negatively associated with the intake of fast foods (P = 0.002) and saturated fats (P = 0.040). These associations remained significant after adjustments for age, rural or urban location, and education. Additional adjustments for body mass index (BMI) and physical activity did not change the results. The results remained significant after further adjustments for menstrual age, menstrual pattern, and oral contraceptive pills.

CONCLUSION

Fast foods and saturated fats were significantly associated with lower AMH concentrations and modifying the amount of these dietary components may be an important strategy for increasing the reservation of ovaries in women. Future longitudinal studies are warranted to confirm these findings and to identify the underlying mechanisms.

Iron intake with the risk of breast cancer among Chinese women: a case-control study

OBJECTIVE

The current study evaluated the associations between different forms and sources of Fe and breast cancer risk in Southern Chinese women.

DESIGN

Case-control study. We collected data on the consumption of Fe from different forms and food sources by using a validated FFQ. Multivariable logistic regression and restricted cubic spline (RCS) analysis was used to reveal potential associations between Fe intake and breast cancer risk.

SETTING

A case-control study of women at three major hospitals in Guangzhou, China.

PARTICIPANTS

From June 2007 to March 2019, 1591 breast cancer cases and 1622 age-matched controls were recruited.

RESULTS

In quartile analyses, Fe from plants and Fe from white meat intake were inversely associated with breast cancer risk, with OR of 0·65 (95 % CI 0·47, 0·89, Ptrend = 0·006) and 0·76 (95 % CI 0·61, 0·96, Ptrend = 0·014), respectively, comparing the highest with the lowest quartile. No associations were observed between total dietary Fe, heme or non-heme Fe, Fe from meat or red meat and breast cancer risk. RCS analysis demonstrated J-shaped associations between total dietary Fe, non-heme Fe and breast cancer, and reverse L-shaped associations between heme Fe, Fe from meat and Fe from red meat and breast cancer.

CONCLUSION

Fe from plants and white meat were inversely associated with breast cancer risk. Significant non-linear J-shaped associations were found between total dietary Fe, non-heme Fe and breast cancer risk, and reverse L-shaped associations were found between heme Fe, Fe from meat or red meat and breast cancer risk.

Sociodemographic factors associated with low intake of bioavailable iron in preschoolers: National Health and Nutrition Survey 2012, Mexico

BACKGROUND

Children < 5 years of age are at risk of developing an iron deficiency due to a low intake of bioavailable iron (FeBio). Few studies have estimated dietary FeBio in children at a national level in relation to sociodemographic characteristics. This study aimed to estimate FeBio intake and its association with sociodemographic factors among Mexican children aged 12-59 months.

METHODS

A cross-sectional study was carried out. Information on serum ferritin and diet was obtained from a national survey and representative sample of 1012 Mexican children aged 12-59 months. We used a 24-h recall to estimate total iron, heme and non-heme iron, vitamin C, phytates, calcium, and meat intake. We calculated FeBio intake using an algorithm. Differences in FeBio intake were analyzed by area of residence (rural/urban), country region (north, center, south), and socioeconomic status (SES), using linear regression models by age subgroups (12-23 and 24-59 months) and total population, while adjusting for study design.

RESULTS

Total iron intake was 9.2 ± 6.7 mg/d. The estimated average of total FeBio fluctuated between 0.74-0.81 mg/d, with a bioavailability of 9.15-12.03% of total iron. Children aged 12-23 months residing in rural areas consumed less FeBio than those in urban areas (β = - 0.276) (p < 0.05). Children aged 24-59 months with high SES consumed more FeBio (β = 0.158 mg/d) than those of a low SES (p < 0.05).

CONCLUSIONS

FeBio is low in Mexican preschoolers. Being from a rural area and having low SES were negatively associated with FeBio intake. These results can benefit interventions seeking to improve iron status.