Dietary Iron Intake in Pregnant Women in Europe: A Review of 24 Studies from 14 Countries in the Period 1991-2014

A global analysis of the determinants of maternal health and transitions in maternal mortality

The reduction of maternal mortality and the promotion of maternal health and wellbeing are complex tasks. This Series paper analyses the distal and proximal determinants of maternal health, as well as the exposures, risk factors, and micro-correlates related to maternal mortality. This paper also examines the relationship between these determinants and the gradual shift over time from a pattern of high maternal mortality to a pattern of low maternal mortality (a phenomenon described as the maternal mortality transition). We conducted two systematic reviews of the literature and we analysed publicly available data on indicators related to the Sustainable Development Goals, specifically, estimates prepared by international organisations, including the UN and the World Bank. We considered 23 frameworks depicting maternal health and wellbeing as a multifactorial process, with superdeterminants that broadly affect women's health and wellbeing before, during, and after pregnancy. We explore the role of social determinants of maternal health, individual characteristics, and health-system features in the production of maternal health and wellbeing. This paper argues that the preventable deaths of millions of women each decade are not solely due to biomedical complications of pregnancy, childbirth, and the postnatal period, but are also tangible manifestations of the prevailing determinants of maternal health and persistent inequities in global health and socioeconomic development. This paper underscores the need for broader, multipronged actions to improve maternal health and wellbeing and accelerate sustainable reductions in maternal mortality. For women who have pregnancy, childbirth, or postpartum complications, the health system provides a crucial opportunity to interrupt the chain of events that can potentially end in maternal death. Ultimately, expanding the health sector ecosystem to mitigate maternal health determinants and tailoring the configuration of health systems to counter the detrimental effects of eco-social forces, including though increased access to quality-assured commodities and services, are essential to improve maternal health and wellbeing and reduce maternal mortality.

Nutrient Intake among Pregnant Women in Spain and Poland: A Comparative Analysis

Prenatal nutrition plays a crucial role in maternal and child health. This study aims to compare nutrient intake and its adequacy to recommendations among pregnant women in Spain and Poland. The ECLIPSES study in Spain utilized a self-administered food frequency questionnaire, while the PREDISH study in Poland employed a 3-day interview method. We assessed energy and nutrient intake against recommended dietary allowances. The analysis included 583 participants in the first trimester and 465 participants in the third trimester from both countries. Our findings revealed insufficient intake of iron, vitamin D, and vitamin B9 among pregnant women in both Spain and Poland. Significant differences were observed in the intake of energy, carbohydrates, fiber, calcium, iron, and vitamins D, E, C, B6, B9, and B12. Notably, 81.6% and 21.5% of participants did not meet the recommended minimum carbohydrate intake, while 99.8% and 43.8% exceeded the limit for total fat, particularly monounsaturated fatty acids (MUFAs). Tailored dietary guidance based on regional differences is crucial for pregnant women. Although variations in dietary intake were observed, both Spain and Poland faced similar risks of nutritional deficiencies, particularly for iron, vitamin D, and vitamin B9. These findings emphasize the need for enhanced efforts in preventing these deficiencies and promoting optimal prenatal nutrition.

Iron supplementation in pregnant Danish women revisited: Effects on prepartum and postpartum iron deficiency, anemia, serum erythropoietin; including iron status, erythropoietin and anthropometrics in newborns. A randomized, placebo-controlled study

OBJECTIVE

To assess effects of iron supplementation, 66 mg elemental iron daily as ferrous fumarate, on iron status markers during normal pregnancies.

METHODS

Randomized, double-blind, placebo-controlled study of 119 women (62 iron-, 57 placebo -treated) and their newborns. Hemoglobin (Hb), serum (S)-ferritin, S-transferrin saturation percentage (TSAT) and S-erythropoietin (S-EPO) were measured at 14-18, 24-27 weeks of gestation, prepartum, 1 and 8 weeks postpartum.

RESULT

From 24-27 weeks gestation to 8 weeks postpartum, the iron group had higher Hb, S-ferritin and TSAT than the placebo group; prepartum, 11% had iron deficiency (ID) and 0% iron deficiency anemia (IDA) in the iron group, vs 60% and 18% in the placebo group; 8 weeks postpartum 1.6% in the iron group had ID and 1.6% IDA vs 14% and 7% in the placebo group. S-EPO levels in the iron group were lower than in the placebo group (p < 0.001). Mothers prepartum S-EPO values were correlated to newborns cord S-EPO values (p < 0.001). Newborns to iron treated mothers had higher cord S-ferritin levels than those to placebo treated mothers (p = 0.02). Newborn girls had higher cord S-ferritin levels than boys (p < 0.01). There was no impact of iron supplementation on the length of gestation, placental weight, or newborns birth weight. Birth weight was correlated only with mothers' body weight, length of gestation and placental weight.

CONCLUSION

Iron supplementation had a "positive" impact on iron status and Hb both during pregnancy and postpartum, with a low frequency of ID/IDA and also a "positive" influence on newborns iron status.

Ethnic differences in adverse iron status in early pregnancy: a cross-sectional population-based study

We studied ethnic differences in terms of iron status during pregnancy between Dutch women and other ethnicities and explore to what extent these differences can be explained by environmental factors. This cross-sectional population-based study (2002-2006) was embedded in the Generation R study and included a total of 4737 pregnant women from seven ethnic groups (Dutch, Turkish, Moroccan, Cape Verdean, Surinamese-Hindustani, Surinamese-Creole and Antillean). Ethnicity was defined according to the Dutch classification of ethnic background. Ferritin, iron and transferrin were measured in early pregnancy. The overall prevalence of iron deficiency was 7 %, ranging from 4 % in both Dutch and Surinamese-Creoles, to 18 % in Turkish, Moroccan and Surinamese-Hindustani women. Iron overload was most prevalent in Surinamese-Creole (11 %) and Dutch (9 %) women. Socioeconomic factors accounted for 5-36 % of the differences. Income was the strongest socioeconomic factor in the Cape Verdean and Surinamese-Hindustani groups and parity for the Turkish and Moroccan groups. Lifestyle determinants accounted for 8-14 % of the differences. In all groups, the strongest lifestyle factor was folic acid use, being associated with higher iron status. In conclusion, in our population, both iron deficiency and iron overload were common in early pregnancy. Our data suggest that ethnic differences in terms of socioeconomic and lifestyle factors only partly drive the large ethnic differences in iron status. Our data support the development of more specific prevention programmes based on further exploration of socioeconomic inequities, modifiable risk and genetic factors in specific ethnic subgroups, as well as the need for individual screening of iron status before supplementation.

Scientific advice related to nutrient profiling for the development of harmonised mandatory front-of-pack nutrition labelling and the setting of nutrient profiles for restricting nutrition and health claims on foods

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver scientific advice related to nutrient profiling for the development of harmonised mandatory front‐of‐pack nutrition labelling and the setting of nutrient profiles for restricting nutrition and health claims on foods. This Opinion is based on systematic reviews and meta‐analyses of human studies on nutritionally adequate diets, data from the Global Burden of Disease framework, clinical practice guidelines, previous EFSA opinions and the priorities set by EU Member States in the context of their Food‐Based Dietary Guidelines and associated nutrient/food intake recommendations. Relevant publications were retrieved through comprehensive searches in PubMed. The nutrients included in the assessment are those likely to be consumed in excess or in inadequate amounts in a majority of European countries. Food groups with important roles in European diets have been considered. The Panel concludes that dietary intakes of saturated fatty acids (SFA), sodium and added/free sugars are above, and intakes of dietary fibre and potassium below, current dietary recommendations in a majority of European populations. As excess intakes of SFAs, sodium and added/free sugars and inadequate intakes of dietary fibre and potassium are associated with adverse health effects, they could be included in nutrient profiling models. Energy could be included because a reduction in energy intake is of public health importance for European populations. In food group/category‐based nutrient profiling models, total fat could replace energy in most food groups owing to its high‐energy density, while the energy density of food groups with low or no fat content may be well accounted for by the inclusion of (added/free) sugars. Some nutrients may be included in nutrient profiling models for reasons other than their public health importance, e.g. as a proxy for other nutrients of public health importance, or to allow for a better discrimination of foods within the same food category.

Iron supplementation during the first trimester of pregnancy after a national change of recommendation: a Danish cross-sectional study

In 2013, the Danish Health Authorities recommended a change in prophylactic iron supplementation to 40–50 mg/d from gestational week 10. Hence, the aims of the present study were (1) to estimate the prevalence of women who follow the Danish recommendation on iron supplementation during the last 3 weeks of the first trimester of pregnancy and (2) to identify potential sociodemographic, reproductive and health-related pre-pregnancy predictors for iron supplementation during the first trimester. We conducted a cross-sectional study with data from the hospital-based Copenhagen Pregnancy Cohort. Characteristics were analysed by descriptive statistics and multivariable logistic regression analysis was performed to examine the associations between predictors and iron supplementation during the last 3 weeks of the first trimester. The study population consisted of 23 533 pregnant women attending antenatal care at Copenhagen University Hospital - Rigshospitalet from October 2013 to May 2019. The prevalence of iron supplementation according to recommendations was 49⋅1 %. The pre-pregnancy factors of ≥40 years of age, the educational level below a higher degree and a vegetarian or vegan diet were identified as predictors for iron supplementation during the first trimester of pregnancy. Approximately half of the women were supplemented with the recommended dose of iron during the first trimester of pregnancy. We identified pre-pregnancy predictors associated with iron supplementation. Interventions that target women of reproductive age are needed. An enhanced focus on iron supplementation during pregnancy should be incorporated in pre-pregnancy and interpregnancy counselling.

Iron deficiency during the first 1000 days of life: are we doing enough to protect the developing brain?

Iron is essential for the functioning of all cells and organs, most critically for the developing brain in the fundamental neuronal processes of myelination, energy and neurotransmitter metabolism. Iron deficiency, especially in the first 1000 days of life, can result in long-lasting, irreversible deficits in cognition, motor function and behaviour. Pregnant women, infants and young children are most vulnerable to iron deficiency, due to their high requirements to support growth and development, coupled with a frequently inadequate dietary supply. An unrecognised problem is that even if iron intake is adequate, common pregnancy-related and lifestyle factors can affect maternal-fetal iron supply in utero, resulting in an increased risk of deficiency for the mother and her fetus. Although preterm birth, gestational diabetes mellitus and intrauterine growth restriction are known risk factors, more recent evidence suggests that maternal obesity and delivery by caesarean section further increase the risk of iron deficiency in the newborn infant, which can persist into early childhood. Despite the considerable threat that early-life iron deficiency poses to long-term neurological development, life chances and a country's overall social and economic progress, strategies to tackle the issue are non-existent, too limited or totally inappropriate. Prevention strategies, focused on improving the health and nutritional status of women of reproductive age are required. Delayed cord clamping should be considered a priority. Better screening strategies to enable the early detection of iron deficiency during pregnancy and early-life should be prioritised, with intervention strategies to protect maternal health and the developing brain.

The Influence of Iron and Zinc Supplementation on Iron Apparent Absorption in Rats Fed Vitamins and Minerals Reduced Diets

Deficient human diet is usually reduced in many nutrients, but animal studies on iron absorption have been only carried out for rats fed well-balanced (control) and iron-deficient diets. The aim of this study was to evaluate the effect of iron or iron/zinc supplementation on iron apparent absorption (IAA) in rats fed a diet reduced in all vitamins and minerals (R). The study was conducted on 77, 6-week-old male Wistar rats in 3 stages as follows: stage I, 4-week period of adaptation to R diet (50% less vitamins and minerals compared to AIN-93M recommendations); stage II, 4-week supplementation period with iron (RSFe) or iron/zinc (RSFeZn); stage III, 2-week post-supplementation period (rats fed R diet). Feces samples to IAA determination were collected at the 20-22nd days of stage I and II and the 10-12th days of stage III. To determine the changes in IAA after introducing and discontinuation of supplementation, feces were collected for 3 days after introducing (stage II) and 5 days after the supplementation discontinuation (stage III). At the end of stage II, compared to R rats, the IAA was statistically significantly higher in RSFe and RSFeZn rats (30.3 ± 2.0% vs. 47.4 ± 1.2% and 51.0 ± 1.7%, respectively). After introducing iron or iron/zinc supplementation, the IAA stabilized fast already in the first day, while after discontinuation of the supplementation, at least 4 days was required to the stabilization. At the end of stage III, the IAA was significantly lower in RSFe (15.8 ± 6.6%) than in RSFeZn rats (43.4 ± 5.9%). In conclusion, to confirm that iron and zinc supplementation is more beneficial than iron supplementation only, especially after discontinuation of supplementation, further research among humans is necessary.

Lactoferrin for Prevention and Treatment of Anemia and Inflammation in Pregnant Women: A Comprehensive Review

Pregnancy is a physiological state that demands higher level of nutrients, including vitamins and minerals, for the growth and maintenance of the fetus. Iron deficiency is a part of most common diet deficiencies in pregnancy and has high clinical significance leading to the development of syderopenic anemia and its consequences for mother and child, such as higher risk of perinatal death, susceptibility to infection, intra-uteral growth inhibition, prematurity and low birth weight. Hence, iron supplementation is recommended for pregnant women; however dietary intake of iron from most commercially available formulas is often insufficient due to iron-poor bioavailability, or have undesired side-effects in the gastrointestinal tract, resulting in a discouraging and distrustful attitude to such treatment. The results of numerous studies indicate that diet supplementation with lactoferrin (LTF), an iron-binding protein, may be advantageous in prophylaxis and treatment of iron deficiency anemia. LTF, administered orally, normalizes iron homeostasis, not only by facilitating iron absorption, but also by inhibiting inflammatory processes responsible for anemia of chronic diseases, characterized by a functional iron deficit for physiological processes. LTF also protects against infections and inflammatory complications, caused by diagnostic surgical interventions in pregnant women. Beneficial, multidirectional actions of LTF during pregnancy encompass, in addition, inhibition of oxidative stress, normalization of intestine and genital tract microbiota and carbohydrate-lipid metabolism, protection of intestine barrier function, promotion of wound healing, as well as hypotensive, analgesic and antistress actions. Bovine lactoferrin (BLTF) is readily available on the nutritional market and generally recognized as safe (GRAS) for use in human diet.

Analysis of Environmental Determinants of Heme and Nonheme Iron Intake in a National Sample of Polish Adolescents

Intake of sufficient amounts of iron by adolescents is a matter of great concern. Therefore, it is crucial to determine the factors that may influence iron intake in this specific population. The present study aimed to analyze the environmental determinants of the intake of heme and nonheme iron in a national homogenous sample of Polish adolescents. Adolescents (aged 15-20 years) were randomly chosen from all the regions of Poland by performing a sampling of secondary schools (random quota sampling). The total iron intake, as well as the intake of heme iron, nonheme iron, animal iron, plant iron, and iron from various food products, was assessed among 1385 female respondents and 1025 male respondents using the validated IRON Intake Calculation-Food Frequency Questionnaire (IRONIC-FFQ). The intake was compared between the subgroups stratified by meat intake in the region, gross domestic product (GDP) in the region, and size of the city (rural vs. urban environment). It was observed that meat intake in the region did not influence the intake of total iron, as well as the intake of heme iron, nonheme iron, animal iron, plant iron, and iron from various food products (p > 0.05). However, GDP and the size of the city were determined as the most influencing factors, as they were associated with iron intake in both female and male adolescents, with the most prominent differences between the subgroups found in the case of females. Female adolescents from high-GDP regions had significantly higher intake of heme iron (p = 0.0047) and animal iron (p = 0.0029), and lower intake of nonheme iron compared to those from low-GDP regions (p = 0.0342). The total iron intake was higher among female adolescents who were from medium cities than those from big cities (p = 0.0350), but significantly higher animal iron intake (p = 0.0404) and plant iron intake (p = 0.0385) were observed among females from villages and small towns compared to females from other groups. Based on the results, it may be concluded that size of the city and the economic status of the region are the most important environmental determinants of iron intake in adolescents and, hence, they should be taken into account while developing educational programs, especially for the female adolescent population.

Iron, iodine and vitamin D deficiencies during pregnancy: epidemiology, risk factors and developmental impacts

Micronutrient deficiency persists throughout the world, and although the burden is higher in low-resource settings, it is also prevalent in wealthy countries, a phenomenon termed 'hidden hunger'. Due to their high requirements for vitamins and minerals relative to their energy intake, young women and children are particularly vulnerable to hidden hunger. As they share several risk factors and impact on overlapping outcomes, we consider how deficiency of iron, iodine and vitamin D can have profound impacts on perinatal health and infant development. We review the epidemiology of these micronutrient deficiencies during pregnancy, including social, environmental and dietary risk factors. We identify the main challenges in defining nutritional status of these nutrients using validated diagnostic criteria linked with meaningful clinical outcomes. Public health strategies are urgently required to improve the overall health and nutritional status of women of reproductive age. Obesity prevention and early detection of malnutrition with standardised screening methods would detect pregnant women at increased risk of iron deficiency. Development of sensitive, individual biomarkers of iodine status is required to protect maternal health and fetal/infant brain development. Risk assessments of vitamin D requirements during pregnancy need to be revisited from the perspective of fetal and neonatal requirements. International consensus on standardised approaches to micronutrient assessment, analysis and reporting as well as sensitive, clinically validated infant and child neuro-behavioural outcomes will enable progression of useful observational and intervention studies.

Iron

Iron deficiency anemia affects approximately one-third of the world's population, and about half the cases are due to iron deficiency. The latest research on iron metabolism published in original articles and systematic reviews is described, and references to recent reviews provided. The topics include dietary sources and bioavailability, iron homeostasis, functions of iron in the body, and biomarkers of status. The consequences of iron deficiency and excess are discussed, with particular focus on vulnerable populations such as pregnant women, infants and the elderly. The newest dietary recommendations, including dietary reference values and food based dietary guidelines, are briefly summarized, followed by the latest developments in food fortification and iron supplementation.

Dietary Iron Intakes in Men in Europe Are Distinctly Above the Recommendations: A Review of 39 National Studies From 20 Countries in the Period 1995 - 2016

The objective of this review was to assess whether dietary iron intake in men in Europe is in symphony with the dietary recommendations. A literature search of national dietary surveys reporting the intake of iron using PubMed, Google Scholar, National Nutrient Databases and previous literature on dietary reviews was performed. The subjects were men aged 18 - 70 years. A total of 39 national dietary surveys in 20 European countries in the period 1995 - 2016 were included. There were considerable differences between median/mean iron dietary intake in the 20 countries. Seven countries/regions, UK-Northern Ireland, UK-Wales, Sweden, Belgium, UK-Scotland, UK-England and Serbia reported median/mean iron intake ranging from 10.5 to 11.6 mg/day. Ten countries, Norway, Finland, Lithuania, Italy, Hungary, Portugal, The Netherlands, Denmark, Iceland and Austria reported iron intake from 12.0 to 13.5 mg/day. France, Germany, Ireland and Spain reported iron intake from 14.8 to 16.0 mg/day, while Poland and Slovakia reported the highest intake of 17.2 and 22.7 mg/day. In surveys from France and The Netherlands, intake of heme iron constituted 11% of total dietary iron intake. Nutrient density for iron, reported in five countries, varied from median 11.6 mg iron/10 MJ in Denmark to 16.0 in France. In all countries, the majority of men had a dietary iron intake markedly above a recommended intake of 9 mg/day. In Europe, 75-87% of men have a dietary iron intake above 9 mg/day. A high iron intake together with relatively high intakes of meat and alcohol contributes to a high iron status and a high frequency of body iron overload in many men. We need consensus on common European standardized dietary methods, uniform dietary reference values and uniform statistical methods to perform inter-country comparisons.