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

Bioaccessibility and Caco-2 cell uptake of iron chlorophyllin using a biologically relevant digestion model

Iron deficiency remains a top nutrient deficiency worldwide. Iron chlorophyllin (IC), a compound structurally analogous to heme, utilizes the protoporphyrin ring of chlorophyll to bind iron. IC has previously been shown to deliver more iron to Caco-2 cells than FeSO4, the most common form prescribed for supplementation. However, previous test conditions used digestive conditions outside of those observed in humans. This study sought to assess IC bioaccessibility and Caco-2 cell uptake using physiologically relevant digestive solutions, pH, and incubation time, as compared to other iron sources (i.e., FeSO4, and hemoglobin (Hb)). Co-digestion with ascorbic acid (AA) and albumin was also investigated. Following gastric, duodenal, and jejunal digestion, IC-bound iron was less bioaccessible than iron delivered as FeSO4, and IC-bound iron was less bioaccessible than Hb-bound iron. IC-bound iron bioaccessibility was not affected by AA and was enhanced 2x when co-digested with a low dose of albumin. However, Caco-2 cell incubation with IC-containing digesta increased cell ferritin 2.5x more than FeSO4 alone, and less than Hb. IC with AA or with 400 mg albumin also increased cell ferritin more than IC alone, with the greatest increases observed following incubation of digesta containing IC + AA + 400 mg albumin. These results suggest IC can serve as an improved source of iron for supplementation as compared to FeSO4. These results also support further in vivo investigations of IC-based iron delivery in populations at risk of iron deficiency.

Multidimensional engineering of Saccharomyces cerevisiae for the efficient production of heme by exploring the cytotoxicity and tolerance of heme

Heme has attracted considerable attention due to its indispensable biological roles and applications in healthcare and artificial foods. The development and utilization of edible microorganisms instead of animals to produce heme is the most promising method to promote the large-scale industrial production and safe application of heme. However, the cytotoxicity of heme severely restricts its efficient synthesis by microorganisms, and the cytotoxic mechanism is not fully understood. In this study, the effect of heme toxicity on Saccharomyces cerevisiae was evaluated by enhancing its synthesis using metabolic engineering. The results showed that the accumulation of heme after the disruption of heme homeostasis caused serious impairments in cell growth and metabolism, as demonstrated by significantly poor growth, mitochondrial damage, cell deformations, and chapped cell surfaces, and these features which were further associated with substantially elevated reactive oxygen species (ROS) levels within the cell (mainly H2O2 and superoxide anion radicals). To improve cellular tolerance to heme, 5 rounds of laboratory evolution were performed, increasing heme production by 7.3-fold and 4.2-fold in terms of the titer (38.9 mg/L) and specific production capacity (1.4 mg/L/OD600), respectively. Based on comparative transcriptomic analyses, 32 genes were identified as candidates that can be modified to enhance heme production by more than 20% in S. cerevisiae. The combined overexpression of 5 genes (SPS22, REE1, PHO84, HEM4 and CLB2) was shown to be an optimal method to enhance heme production. Therefore, a strain with enhanced heme tolerance and ROS quenching ability (R5-M) was developed that could generate 380.5 mg/L heme with a productivity of 4.2 mg/L/h in fed-batch fermentation, with S. cerevisiae strains being the highest producers reported to date. These findings highlight the importance of improving heme tolerance for the microbial production of heme and provide a solution for efficient heme production by engineered yeasts.

Bioproduction of porphyrins, phycobilins, and their proteins using microbial cell factories: engineering, metabolic regulations, challenges, and perspectives

Porphyrins, phycobilins, and their proteins have abundant π-electrons and strongly absorb visible light, some of which bind a metal ion in the center. Because of the structural and optical properties, they not only play critical roles as an essential component in natural systems but also have attracted much attention as a high value specialty chemical in various fields, including renewable energy, cosmetics, medicines, and foods. However, their commercial application seems to be still limited because the market price of porphyrins and phycobilins is generally expensive to apply them easily. Furthermore, their petroleum-based chemical synthesis is energy-intensive and emits a pollutant. Recently, to replace petroleum-based production, many studies on the bioproduction of metalloporphyrins, including Zn-porphyrin, Co-porphyrin, and heme, porphyrin derivatives including chlorophyll, biliverdin, and phycobilins, and their proteins including hemoproteins, phycobiliproteins, and phytochromes from renewable carbon sources using microbial cell factories have been reported. This review outlines recent advances in the bioproduction of porphyrins, phycobilins, and their proteins using microbial cell factories developed by various microbial biotechnology techniques, provides well-organized information on metabolic regulations of the porphyrin metabolism, and then critically discusses challenges and future perspectives. Through these, it is expected to be able to achieve possible solutions and insights and to develop an outstanding platform to be applied to the industry in future research.

Promoting Heme and Phycocyanin Biosynthesis in Synechocystis sp. PCC 6803 by Overexpression of Porphyrin Pathway Genes with Genetic Engineering

Due to their unique biochemical and spectroscopic properties, both heme and phycocyanobilin are widely applied in the medical and food industries. Synechocystis sp. PCC 6803 contains both heme and phycocyanin, and is capable of synthesizing phycocyanin using heme as a precursor. The aim of this study was to uncover viable metabolic targets in the porphyrin pathway from Synechocystis sp. PCC 6803 to promote the accumulation of heme and phycocyanin in the recombinant strains of microalgae. A total of 10 genes related to heme synthesis pathway derived from Synechococcus elongatus PCC 7942 and 12 genes related to endogenous heme synthesis were individually overexpressed in strain PCC 6803. The growth rate and pigment content (heme, phycocyanin, chlorophyll a and carotenoids) of 22 recombinant algal strains were characterized. Quantitative real-time PCR technology was used to investigate the molecular mechanisms underlying the changes in physiological indicators in the recombinant algal strains. Among the 22 mutant strains, the mutant overexpressing the haemoglobin gene (glbN) of strain PCC 6803 had the highest heme content, which was 2.5 times higher than the wild type; the mutant overexpressing the gene of strain PCC 7942 (hemF) had the highest phycocyanin content, which was 4.57 times higher than the wild type. Overall, the results suggest that genes in the porphyrin pathway could significantly affect the heme and phycocyanin content in strain PCC 6803. Our study provides novel crucial targets for promoting the accumulation of heme and phycocyanin in cyanobacteria.

Improved biosynthesis of heme in Bacillus subtilis through metabolic engineering assisted fed-batch fermentation

BACKGROUND

Heme is an iron/porphyrin complex compound, widely used in the health care, food, and pharmaceutical industries. It is more advantageous and attractive to develop microbial cell factories to produce heme by fermentation, with lower production costs and environmentally more friendly procedures than those of the traditional extraction based on animal blood. In this study, Bacillus subtilis, a typical industrial model microorganism of food safety grade, was used for the first time as the host to synthesize heme.

RESULTS

The heme biosynthetic pathway was engineered as four modules, the endogenous C5 pathway, the heterologous C4 pathway, the uroporphyrinogen (urogen) III synthesis pathway, and the downstream synthesis pathway. Knockout of hemX encoding the negative effector of the concentration of HemA, overexpression of hemA encoding glutamyl-tRNA reductase, and knockout of rocG encoding the major glutamate dehydrogenase in the C5 pathway, resulted in an increase of 427% in heme production. Introduction of the heterologous C4 pathway showed a negligible effect on heme biosynthesis. Overexpression of hemCDB, which encoded hydroxymethylbilane synthase, urogen III synthase, and porphobilinogen synthase participating in the urogen III synthesis pathway, increased heme production by 39%. Knockouts of uroporphyrinogen methyltransferase gene nasF and both heme monooxygenase genes hmoA and hmoB in the downstream synthesis pathway increased heme production by 52%. The engineered B. subtilis produced 248.26 ± 6.97 mg/L of total heme with 221.83 ± 4.71 mg/L of extracellular heme during the fed-batch fermentation in 10 L fermenter.

CONCLUSIONS

Strengthening endogenous C5 pathway, urogen III synthesis pathway and downstream synthesis pathway promoted the biosynthesis of heme in B. subtilis. The engineered B. subtilis strain has great potential as a microbial cell factory for efficient industrial heme production.

Applications of the Whole-Cell System in the Efficient Biosynthesis of Heme

Heme has a variety of functions, from electronic reactions to binding gases, which makes it useful in medical treatments, dietary supplements, and food processing. In recent years, whole-cell system-based heme biosynthesis methods have been continuously explored and optimized as an alternative to the low-yield, lasting, and adverse ecological environment of chemical synthesis methods. This method relies on two biosynthetic pathways of microbial precursor 5-aminolevulinic acid (C4, C5) and three known downstream biosynthetic pathways of heme. This paper reviews the genetic and metabolic engineering strategies for heme production in recent years by optimizing culture conditions and techniques from different microorganisms. Specifically, we summarized and analyzed the possibility of using biosensors to explore new strategies for the biosynthesis of heme from the perspective of synthetic biology, providing a new direction for future exploration.

Improved production of heme using metabolically engineered Escherichia coli

Heme has recently attracted much attention due to its promising applications in food and healthcare industries. However, the current titers and productivities of heme produced by recombinant microorganisms are not high enough for a wide range of applications. In this study, the process for the fermentation of the metabolically engineered E. coli HAEM7 strain was optimized for the high-level production of heme. To improve the production of heme, different carbon sources, iron concentration in the medium, pH control strategies, induction points, and iron content in feeding solution were examined. Moreover, strategies of increasing cell density, regular iron supplementation, and supply of excess feeding solution were developed to further improve the production of heme. In the optimized fermentation process, the HAEM7 strain produced 1.03 g/L heme with a productivity of 21.5 mg/L/h. The fermentation process and strategies reported here will expedite establishing industry-level production of heme. This article is protected by copyright. All rights reserved.

Hemin with Peroxidase Activity Can Inhibit the Oxidative Damage Induced by Ultraviolet A

Excessive reactive oxygen species (ROS), a highly reactive substance that contains oxygen, induced by ultraviolet A (UVA) cause oxidative damage to skin. We confirmed that hemin can catalyze the reaction of tyrosine (Tyr) and hydrogen peroxide (H₂O₂). Catalysis was found to effectively reduce or eliminate oxidative damage to cells induced by H₂O₂ or UVA. The scavenging effects of hemin for other free-radical ROS were also evaluated through pyrogallol autoxidation, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·)-scavenging assays, and phenanthroline–Fe²⁺ assays. The results show that a mixture of hemin and tyrosine exhibits strong scavenging activities for H₂O₂, superoxide anion (O₂⁻·), DPPH·, and the hydroxyl radical (·OH). Furthermore, the inhibition of oxidative damage to human skin keratinocyte (HaCaT) cells induced by H₂O₂ or UVA was evaluated. The results show that catalysis can significantly reduce the ratio of cell apoptosis and death and inhibit the release of lactate dehydrogenase (LDH), as well as accumulation of malondialdehyde (MDA). Furthermore, the resistance to apoptosis was found to be enhanced. These results show that the mixture of hemin and tyrosine has a significantly protective effect against oxidative damage to HaCaT cells caused by UVA, suggesting it as a protective agent for combating UVA damage.

Manan N, Mohamad Alwi MN. Effect of vitamin D3-fortified fruit juice supplementation of 4000 IU daily on the recovery of iron status in childbearing-aged women with marginally low iron stores: Protocol for an 8-week, parallel group, double-blind randomized controlled trial

BACKGROUND

In recent years, emerging evidence has highlighted the role of vitamin D as an iron absorption enhancer by suppressing hepcidin concentration, albeit with an unclear underlying mechanism. Dietary-based approach in improving iron status has been widely practised, however, there is a scarcity in randomized controlled trials (RCT) to elucidate the effect of vitamin D-fortified juice on iron status recovery. Therefore, this study aims to investigate the effect of an 8-week vitamin D3-fortified fruit juice supplementation on iron status indicators in childbearing-aged women with marginally low iron stores.

METHODS

In a placebo-controlled, double-blind, RCT, a total of 120 women aged between 19-40 with serum ferritin < 20 μg/l and fulfilled the eligibility criteria will be randomized into consuming either vitamin D3-fortified fruit juices containing 4000 IU (100 mcg) (vitamin D) or placebo-fruit juices (placebo) daily for eight weeks. At every 4-week interval, 10 ml fasting blood sample, information on dietary habit and anthropometric measurement will be collected. A mixed model repeated-measures analysis of variance will be performed to determine the effect of the intervention and the interaction with time points for all iron and vitamin D status blood biomarkers.

DISCUSSION

Vitamin D supplementation in food fortification as a novel iron absorption enhancer might be a future and relevant alternative management of iron deficiency as opposed to the oral iron therapy that has poor adherence.

TRIAL REGISTRATION

Clinicaltrials.gov: registration number NCT04618289, registration date October 28, 2020, protocol ID JKEUPM-2020-033.

Factors associated with serum ferritin levels and iron excess: results from the EPIC-EurGast study

PURPOSE

Excess iron is involved in the development of non-communicable diseases such as cancer, type 2 diabetes and cardiovascular conditions. We aimed to describe the prevalence of excess iron and its determinants in healthy European adults.

METHODS

Sociodemographic, lifestyle, iron status, dietary information, and HFE genotyping were obtained from controls from the nested case-control study EPIC-EurGast study. High sensitivity C-reactive protein (hsCRP) was measured to address possible systemic inflammation. Descriptive and multivariate analyses were used to assess iron status and its determinants.

RESULTS

Out of the 828 participants (median age: 58.7 years), 43% were females. Median serum ferritin and prevalence of excess iron were 143.7 µg/L and 35.2% in males, respectively, and 77 µg/L and 20% in females, both increasing with latitude across Europe. Prevalence of HFE C282Y mutation was significantly higher in Northern and Central Europe (~ 11%) than in the South (5%). Overweight/obesity, age, and daily alcohol and heme iron intake were independent determinants for iron status, with sex differences even after excluding participants with hsCRP > 5 mg/L. Obese males showed a greater consumption of alcohol, total and red meat, and heme iron, compared with those normal weight.

CONCLUSION

Obesity, higher alcohol and heme iron consumption were the main risk factors for excess iron in males while only age was associated with iron overload in females. Weight control and promoting healthy lifestyle may help prevent iron overload, especially in obese people. Further research is needed to clarify determinants of excess iron in the healthy adult population, helping to reduce the associated comorbidities.

Biotechnological advances for improving natural pigment production: a state-of-the-art review

In current years, natural pigments are facing a fast-growing global market due to the increase of people's awareness of health and the discovery of novel pharmacological effects of various natural pigments, e.g., carotenoids, flavonoids, and curcuminoids. However, the traditional production approaches are source-dependent and generally subject to the low contents of target pigment compounds. In order to scale-up industrial production, many efforts have been devoted to increasing pigment production from natural producers, via development of both in vitro plant cell/tissue culture systems, as well as optimization of microbial cultivation approaches. Moreover, synthetic biology has opened the door for heterologous biosynthesis of pigments via design and re-construction of novel biological modules as well as biological systems in bio-platforms. In this review, the innovative methods and strategies for optimization and engineering of both native and heterologous producers of natural pigments are comprehensively summarized. Current progress in the production of several representative high-value natural pigments is also presented; and the remaining challenges and future perspectives are discussed.

Modulation of Functional Characteristics of Mesenchymal Stromal Cells by Acellular Preparation of Porcine Hemoglobin

Exploring the potential usage of the acellular preparation of porcine hemoglobin (PHb) isolated from slaughterhouse blood as a cell culture media component, we have tested its effects on the functional characteristics of stromal cells of mesodermal origin. Human peripheral blood mesenchymal stromal cells (PB-MSCs) were used in this study as a primary cell model system, along with three mouse cell lines (ATDC5, MC3T3-E1, and 3T3-L1), which represent more uniform model systems. We investigated the effect of PHb at concentrations of 0.1, 1, and 10 μM on these cells’ proliferation, cycle, and clonogenic and migratory potential, and found that PHb’s effect depended on both the cell type and its concentration. At the lowest concentration used (0.1 μM), PHb showed the least evident impact on the cell growth and migration; hence, we analyzed its effect on mesenchymal cell multilineage differentiation capacity at this concentration. Even under conditions that induce a specific type of MSC differentiation (cultivation in particular differentiation media), PHb modulated chondrogenic, osteogenic, and adipogenic differentiation, making it a potential candidate for a supplement of MSC culture. Through a model of porcine hemoglobin, these findings also contribute to improving the knowledge of extracellular hemoglobin’s influence on MSCs >in vivo.

Challenges and opportunities of bioprocessing 5-aminolevulinic acid using genetic and metabolic engineering: a critical review

5-Aminolevulinic acid (5-ALA), a non-proteinogenic five-carbon amino acid, has received intensive attentions in medicine due to its approval by the US Food and Drug Administration (FDA) for cancer diagnosis and treatment as photodynamic therapy. As chemical synthesis of 5-ALA performed low yield, complicated processes, and high cost, biosynthesis of 5-ALA via C4 (also called Shemin pathway) and C5 pathway related to heme biosynthesis in microorganism equipped more advantages. In C4 pathway, 5-ALA is derived from condensation of succinyl-CoA and glycine by 5-aminolevulic acid synthase (ALAS) with pyridoxal phosphate (PLP) as co-factor in one-step biotransformation. The C5 pathway involves three enzymes comprising glutamyl-tRNA synthetase (GltX), glutamyl-tRNA reductase (HemA), and glutamate-1-semialdehyde aminotransferase (HemL) from α-ketoglutarate in TCA cycle to 5-ALA and heme. In this review, we describe the recent results of 5-ALA production from different genes and microorganisms via genetic and metabolic engineering approaches. The regulation of different chassis is fine-tuned by applying synthetic biology and boosts 5-ALA production eventually. The purification process, challenges, and opportunities of 5-ALA for industrial applications are also summarized.

Pulse Probiotic Superfood as Iron Status Improvement Agent in Active Women-A Review

Active women or women of reproductive age (15–49 years old) have a high risk of suffering from anaemia. Anaemia is not solely caused by iron deficiency, however, the approaches to improve iron status in both cases are greatly related. Improving the iron status of active women can be done by dietary intervention with functional food. This review aims to provide insights about the functional food role to increase iron absorption in active women and the potency of pulse probiotic superfood development in dry matrices. Results showed that the beneficial effect of iron status is significantly improved by the synergic work between probiotic and prebiotic. Furthermore, chickpeas and lentils are good sources of prebiotic and the consumption of pulses are related with 21st century people’s intention to eat healthy food. There are wide possibilities to develop functional food products incorporated with probiotics to improve iron status in active woman.

Iron supplementation and iron-fortified foods: a review

About one-third of the world population is suffering from iron deficiency. Delivery of iron through diet is a practical, economical, and sustainable approach. Clinical studies have shown that the consumption of iron-fortified foods is one of the most effective methods for the prevention of iron deficiency. However, supplementing iron through diet can cause undesirable side-effects. Thus, it is essential to develop new iron-rich ingredients, iron-fortified products with high bioavailability, better stability, and lower cost. It is also essential to develop newer processing technologies for more effective fortification. This review compared the iron supplementation strategies used to treat the highly iron-deficient population and the general public. We also reviewed the efficacy of functional (iron-rich) ingredients that can be incorporated into food materials to produce iron-fortified foods. The most commonly available foods, such as cereals, bakery products, dairy products, beverages, and condiments are still the best vehicles for iron fortification and delivery.Scope of reviewThe manuscript aims at providing a comprehensive review of the latest publications that cover three aspects: administration routes for iron supplementation, iron-rich ingredients used for iron supplementation, and iron-fortified foods.

Classic and emergent indicators for the assessment of human iron status

Iron deficiency is the leading cause of anemia, a significant global public health problem. Different methods exist for assessing iron nutritional status, including laboratory tests that focus on storage, transportation, and iron functional compartment parameters. Classical markers such as bone marrow, serum iron, ferritin, hemoglobin, erythrocyte parameters, transferrin, transferrin receptors, and zinc protoporphyrin are discussed in this review. Additional parameters calculated from these indicators, including transferrin saturation, ferritin index and Thomas plot, and some emergent parameters such as hepcidin, erythroferrone, and low hemoglobin density are also discussed. There is no a single indicator for assessing iron nutritional status. Therefore, the use of more than one indicator may be the best practice to obtain the correct diagnosis, also considering the influence of inflammation/infection on many of these indicators. The constant validation of the current parameters, the improvement of assessment methods, and the identification of new indicators will be the key to refine the assessment of iron nutritional status and the right choice of treatment for its improvement.

Heme as a Taste Molecule

PURPOSE OF REVIEW

The sense of taste has evolved to enable the identification of appropriate substances to consume, to acquire nutrients, and to avoid consuming potential toxins. Five basic taste classes have been recognized, although there may be others, including metallic taste, which have not been well defined. The purpose of this review was to survey available data from diverse sources to determine how much was known about the molecular basis for metallic taste.

RECENT FINDINGS

Metallic taste has been studied in the context of dysgeusia, primarily using non-heme iron as an inducer of metallic taste sensation. However, recent efforts by industry to develop plant-based meat substitutes have suggested that iron in the form of heme may be the main molecule underlying the taste of meat. Little work has been done on heme as a taste molecule. Data support a primary role for heme in metallic taste that may have evolved as part of a means to consume and preserve elemental iron for physiological needs.

Native bovine hemoglobin reduces differentiation capacity of mesenchymal stromal cells in vitro

We have tested in vitro effects of hemoglobin from bovine slaughterhouse blood (BHb) on stromal cells of mesodermal origin, with an aim to explore its use as a component of cell culture media. Human peripheral blood mesenchymal stromal cells (PB-MSCs) and three mouse cell lines (ATDC5, MC3T3-E1 and 3T3-L1) were employed to study BHb effects on their growth and migration. The cells multilineage differentiation capacity in the presence of BHb was evaluated after induced differentiation, by histochemical staining and by RT-PCR analysis of the expression of genes specific for chondrogenic, adipogenic and osteogenic lineages. The effects of BHb on the cell proliferation and motility were dependent on both, cell type and BHb concentration (0.1 μM, 1 μM and 10 μM). In the lowest concentration (0.1 µM) BHb showed the least prominent effect on the cell proliferation and migration. In this concentration BHb reduced the differentiation capacity of all tested cells and its effect was dependent of composition of induction medium and the culture period. Obtained data suggest that BHb has the potential to be used as a component of cell culture media through maintaining proliferation and reducing differentiation capacity of mesenchymal stromal cells.

Characterization of Isolated Extracts from Justicia Plant Leaves used as Remedy for Anemia

Indigenous populations use plants as an important healthcare resource or remedy for different diseases. Here, isolated extracts from Justicia (family Acanthanceae) plant leaves used in Africa as remedy for anemia are characterized by different methods to assess composition and potential nutritional or therapeutic value. Extracts from Justicia leaves were obtained by aqueous extraction, with further isolation by centrifuging and high-performance liquid chromatography. Extracts and isolated compounds were characterized by ultraviolet-visible (UV-Vis) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS). Hemoglobin activity was assessed using different hemoglobin assays (Cayman Chemical, and Sigma-Aldrich), as well as ELISA. In addition, the safety of the isolated samples was assessed in vitro and in vivo in mice. ICP-MS study results revealed many essential metabolites found in blood plasma. The UV-Vis spectroscopy results highlighted the presence of hemoglobin, with assays showing levels over 4 times higher than that of similar mass of lyophilized human hemoglobin. Meanwhile, in vivo studies showed faster recovery from anemia in mice administered with the isolated extracts compared to untreated mice. Moreover, in vitro and in vivo studies highlighted safety of the extracts. This study reveals the presence of high levels of elements essential for blood health in the isolated extracts from Justicia plant leaves. The findings inspire further research with the potential applications in food fortification, and as remedy for blood disorders like anemia, which disproportionally affects cancer patients, pregnant women, and populations in low- and middle-income countries.

Analysis of Heme and Non-Heme Iron Intake and Iron Dietary Sources in Adolescent Menstruating Females in a National Polish Sample

Iron intake and heme/non-heme iron proportions are crucial for iron deficiency anemia prevention. Women of childbearing age are indicated by World Health Organization as the primary target group, but maintaining iron balance is particularly challenging for adolescents. The aim of the presented study was to analyze heme and non-heme iron intake and dietary sources in adolescent menstruating females in a national Polish sample. The study was conducted in a representative sample of adolescents (aged 15-20) who were recruited from all regions of Poland based on secondary school sampling (random quota sampling), with 1385 female adolescents being included in the sample. The iron intake was assessed using the previously validated IRONIC-FFQ (IRON Intake Calculation-Food Frequency Questionnaire). The intakes of iron, heme iron, non-heme iron, and iron from food product groups were assessed and compared with those of male adolescents (n = 1025) who were recruited from the same schools, as well as between sub-groups stratified by age, body mass index, anemia history, following vegetarian diet, applying iron supplementation and school type. Compared with male individuals, females were characterized by a lower intake of all forms of iron. It was stated that non-heme iron intake was highest in younger ones, overweight ones, vegetarian ones, and comprehensive school students. Female adolescents with anemia history were characterized by similar iron intake as others. For the target group, there is inadequate nutritional education and a necessity to broaden the knowledge about specific sources of iron.

Heme-bound iron in treatment of pregnancy-associated iron deficiency anemia

Background

The iron requirements increase during the second and third trimesters of pregnancy. Maternal anemia is a leading cause of adverse perinatal outcome.

Objectives

This study was designed to evaluate the efficacy of the heme-bound iron in treatment of pregnancy-associated iron deficiency anemia (IDA).

Materials and Methods

In all, 122 women with IDA during pregnancy and hemoglobin ≤10 g/dL were studied. The studied women were treated with heme-bound iron tablets for ≥3 months. Pretreatment hemoglobin, ferritin, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were compared with the posttreatment values to detect the efficacy of heme-bound iron (Optifer^®) in treatment of IDA during pregnancy.

Results

The mean pretreatment hemoglobin significantly increased from 8.4 ± 2.7 to 11.2 ± 2.1 g/dL and the mean pretreatment ferritin level significantly increased from 22.6 ± 5.6 to 112.8 ± 4.8 μg/L (P < 0.003 and 0.04; respectively) 3 months after heme-bound iron treatment. In addition, the mean pretreatment red blood cells' MCV and MCH significantly increased from 74.2 ± 4.8 fL and 24.2 ± 7.8 pg, respectively, to 92.0 ± 4.1 fL and 32.6 ± 6.2 pg) (P = 0.04 and 0.007, respectively) 3 months after heme-bound iron treatment.

Conclusion

Heme-bound iron (Optifer^®) is an effective oral iron preparation to treat IDA during pregnancy and to replace the depleted iron store.

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.

Effects of iron supplementation versus dietary iron on the nutritional iron status: Systematic review with meta-analysis of randomized controlled trials

This meta-analysis compared the effects of dietary intervention versus iron supplementation on biochemical parameters related to the iron nutritional status in humans. The PubMed, CENTRAL, LILACS, SCIELO, OPENGREY.EU and ClinicalTrials.gov databases were searched for randomized clinical trials that assigned individuals to a dietary intervention or to an iron supplementation regimen, for 12 weeks or more. The primary outcome was the hemoglobin concentration, and secondary outcomes were ferritin, RDW, mean corpuscular volume, soluble transferrin receptor, total iron binding capacity, serum iron, and transferrin saturation. From the 6095 records identified, twelve studies were included, six with children, five with adolescents/adults, and one with pregnant women. In the subgroup of studies that included anemic/iron deficient children, supplementation significantly increased the hemoglobin concentration (weighted mean difference (WMD): 3.19 g/L [95% CI: 1.31, 5.07]) and induced a significantly greater reduction of the soluble transferrin receptor (WMD: -0.46 mg/L [95% CI: -0.70, -0, 21]), when compared to dietary intervention. It also induced a greater reduction of the total binding capacity of iron in adolescents/adults (WMD: -6.96 μmol/L [95% CI: -12.70, -1.21]). Supplementation showed a better effect on hemoglobin recovery in anemic/iron deficient children, while no differences were observed between supplementation and dietary intervention in treating adolescents/adults.

A Food-Derived Dietary Supplement Containing a Low Dose of Iron Improved Markers of Iron Status Among Nonanemic Iron-Deficient Women

OBJECTIVE

Iron deficiency is the most common nutrient deficiency in the world. While deficiency can often be resolved through dietary supplementation with iron, adverse events are common and frequently preclude compliance. The objective of this study was to determine whether a food-derived dietary supplement containing a low dose of iron and nutrients that increase iron absorption could resolve iron deficiency with fewer adverse events than reported at higher doses.

METHODS

A pilot clinical trial (NCT02683369) was conducted among premenopausal women with nonanemic iron deficiency that was verified by blood screening. Participants consumed a dietary supplement (Blood Builder®/Iron Response®) once daily for 8 weeks containing 26 mg of iron, vitamin C, folate, and other food-derived nutrients. Primary outcomes were markers of iron status (serum ferritin, hemoglobin, soluble transferrin receptor, total body iron stores) and secondary outcomes were self-reported fatigue and energy. All outcomes were assessed at baseline and 8 weeks. Adverse events were monitored with questionnaires, daily diaries, and contact with a physician. Dependent samples t test and Wilcoxon signed-rank test were used to analyze outcomes.

RESULTS

Twenty-three participants enrolled in the study. Iron deficiency was resolved in the sample (mean serum ferritin: baseline = 13.9 μg/L, 8 weeks = 21.1 μg/L, p < 0.001). All other markers of iron status, fatigue, and energy also improved during the study (p < 0.04). No adverse events were reported.

CONCLUSIONS

While larger and controlled studies are needed to confirm these findings, a food-derived dietary supplement with a low dose of iron and absorption-enhancing nutrients resolved iron deficiency and improved all other markers of iron status without any adverse events.

Identification of Genes for Hereditary Hemochromatosis

Hereditary hemochromatosis (HH) is one of the most common genetically transmitted conditions in individuals of Northern European ancestry. The disease is characterized by excessive intestinal absorption of dietary iron, resulting in pathologically high iron storage in tissues and organs. If left untreated, HH can damage joints and organs, and eventually lead to death. There are four main classes of HH, as well as five individual molecular subtypes, caused by mutations in five genes, and the approaches implemented in the discovery of each HH type have specific histories and unique aspects. In this chapter, we review the genetics of the different HH types, including the strategies used to detect the causal variants in each case and the manner in which genetic variants were found to affect iron metabolism.

An Animal-Source Food Supplement Increases Micronutrient Intakes and Iron Status among Reproductive-Age Women in Rural Vietnam

Background: Few studies have examined the impact of local animal-source foods (ASFs) on the nutritional status of reproductive-age women in developing countries.Objective: We hypothesized that a midmorning snack of local ASF for 6 mo would reduce dietary micronutrient deficiencies [usual intake less than the estimated average requirement (EAR)] and improve blood biomarkers of iron, zinc, and vitamins A and B-12 status among nonpregnant, reproductive-age women in rural Vietnam.Methods: One hundred seventeen women, 18-30 y old, were randomly assigned to receive either an ASF (mean: 144 kcal, 8.9 mg Fe, 2.7 mg Zn, 1050 μg retinoic acid equivalent vitamin A, and 5.5 μg vitamin B-12) or a control snack (mean: 150 kcal, 2.0 mg Fe, 0.9 mg Zn, 0 μg retinoic acid equivalent vitamin A, and 0 μg vitamin B-12) 5 d/wk for 6 mo. Usual nutrient intakes were estimated by repeated 24-h dietary recalls. Blood samples were collected at baseline and 3 and 6 mo. Because of the relation between nutritional status and inflammation, serum C-reactive protein, α-1-acid-glycoprotein, and urinary tract infections (UTIs) were also monitored.Results: Eighty-nine women (47 in the ASF group and 42 controls) completed the study. In the ASF group, intakes of iron and vitamins A and B-12 below the EAR were eliminated, and the prevalence of a low zinc intake was reduced to 9.6% compared with 64.7% in controls (P < 0.001). At 6 mo, a modest increase (P < 0.05) in hemoglobin and iron status occurred in the ASF group compared with the control group, but plasma zinc, retinol, and serum vitamin B-12 concentrations did not differ. UTI relative risk was 3.9 (P < 0.05) among women assigned to the ASF group who had a low whole-body iron status at baseline.Conclusions: Adding a small amount of locally produced ASF to the diets of reproductive-age Vietnamese women improved micronutrient intakes and iron status. However, the increased UTI incidence in women in the ASF group with initially lower iron stores warrants further investigation.

Daily iron supplementation for improving anaemia, iron status and health in menstruating women

BACKGROUND

Iron-deficiency anaemia is highly prevalent among non-pregnant women of reproductive age (menstruating women) worldwide, although the prevalence is highest in lower-income settings. Iron-deficiency anaemia has been associated with a range of adverse health outcomes, which restitution of iron stores using iron supplementation has been considered likely to resolve. Although there have been many trials reporting effects of iron in non-pregnant women, these trials have never been synthesised in a systematic review.

OBJECTIVES

To establish the evidence for effects of daily supplementation with iron on anaemia and iron status, as well as on physical, psychological and neurocognitive health, in menstruating women.

SEARCH METHODS

In November 2015 we searched CENTRAL, Ovid MEDLINE, EMBASE, and nine other databases, as well as four digital thesis repositories. In addition, we searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and reference lists of relevant reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing daily oral iron supplementation with or without a cointervention (folic acid or vitamin C), for at least five days per week at any dose, to control or placebo using either individual- or cluster-randomisation. Inclusion criteria were menstruating women (or women aged 12 to 50 years) reporting on predefined primary (anaemia, haemoglobin concentration, iron deficiency, iron-deficiency anaemia, all-cause mortality, adverse effects, and cognitive function) or secondary (iron status measured by iron indices, physical exercise performance, psychological health, adherence, anthropometric measures, serum/plasma zinc levels, vitamin A status, and red cell folate) outcomes.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures of Cochrane.

MAIN RESULTS

The search strategy identified 31,767 records; after screening, 90 full-text reports were assessed for eligibility. We included 67 trials (from 76 reports), recruiting 8506 women; the number of women included in analyses varied greatly between outcomes, with endpoint haemoglobin concentration being the outcome with the largest number of participants analysed (6861 women). Only 10 studies were considered at low overall risk of bias, with most studies presenting insufficient details about trial quality.Women receiving iron were significantly less likely to be anaemic at the end of intervention compared to women receiving control (risk ratio (RR) 0.39 (95% confidence interval (CI) 0.25 to 0.60, 10 studies, 3273 women, moderate quality evidence). Women receiving iron had a higher haemoglobin concentration at the end of intervention compared to women receiving control (mean difference (MD) 5.30, 95% CI 4.14 to 6.45, 51 studies, 6861 women, high quality evidence). Women receiving iron had a reduced risk of iron deficiency compared to women receiving control (RR 0.62, 95% CI 0.50 to 0.76, 7 studies, 1088 women, moderate quality evidence). Only one study (55 women) specifically reported iron-deficiency anaemia and no studies reported mortality. Seven trials recruiting 901 women reported on 'any side effect' and did not identify an overall increased prevalence of side effects from iron supplements (RR 2.14, 95% CI 0.94 to 4.86, low quality evidence). Five studies recruiting 521 women identified an increased prevalence of gastrointestinal side effects in women taking iron (RR 1.99, 95% CI 1.26 to 3.12, low quality evidence). Six studies recruiting 604 women identified an increased prevalence of loose stools/diarrhoea (RR 2.13, 95% CI 1.10, 4.11, high quality evidence); eight studies recruiting 1036 women identified an increased prevalence of hard stools/constipation (RR 2.07, 95% CI 1.35 to 3.17, high quality evidence). Seven studies recruiting 1190 women identified evidence of an increased prevalence of abdominal pain among women randomised to iron (RR 1.55, 95% CI 0.99 to 2.41, low quality evidence). Eight studies recruiting 1214 women did not find any evidence of an increased prevalence of nausea among women randomised to iron (RR 1.19, 95% CI 0.78 to 1.82). Evidence that iron supplementation improves cognitive performance in women is uncertain, as studies could not be meta-analysed and individual studies reported conflicting results. Iron supplementation improved maximal and submaximal exercise performance, and appears to reduce symptomatic fatigue. Although adherence could not be formally meta-analysed due to differences in reporting, there was no evident difference in adherence between women randomised to iron and control.

AUTHORS' CONCLUSIONS

Daily iron supplementation effectively reduces the prevalence of anaemia and iron deficiency, raises haemoglobin and iron stores, improves exercise performance and reduces symptomatic fatigue. These benefits come at the expense of increased gastrointestinal symptomatic side effects.

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.

Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance

Iron is a functional component of oxygen transport and energy production in humans and therefore is a critically important micronutrient for sport and exercise performance. Athletes, particularly female athletes participating in endurance sport, are at increased risk of compromised iron status due to heightened iron losses through menstruation and exercise-induced mechanisms associated with endurance activity. Conventionally oral iron supplementation is used in prevention or/and treatment of iron deficiency. However, this approach has been criticised because of the side effects and increased risk of iron toxicity associated with the use of supplements. Thus, more recently there has been a growing interest in using dietary modification rather than the use of supplements to improve iron status of athletes. Dietary iron treatment methods include the prescription of an iron-rich diet, or/and haem iron-based diet, dietary advice counselling and inclusion of novel iron-rich products into the daily diet. Although studies using dietary modification are still scarce, current literature suggests that dietary iron interventions can assist in maintaining iron status in female athletes, especially during intensive training and competition. Future research should focus on the most efficient method(s) of dietary modification for improvement of iron status and whether these approaches can have a favourable impact on sports and exercise performance.

Dietary iron intervention using a staple food product for improvement of iron status in female runners

BACKGROUND

Adequate nutrient intake is critically important for achieving optimal sports performance. Like all athletes, female runners require a nutritionally balanced diet to maintain daily activities and a successful training regime. This study investigates the effects of cereal product based dietary iron intervention on iron status of recreational female runners (n = 11; 32 ± 7yr; 239 ± 153 minutes exercise/week, of which 161 ± 150 minutes running activity/week; VO2max 38 ± 4 ml/kg/min).

METHODS

Participants completed a 6-week dietary intervention study. They were asked to replace their usual bread with iron-rich Teff bread as part of their daily diet. During this period, their dietary habits were assessed by multiple pass 24-hr recalls; iron status was determined by venous blood analysis for serum transferrin, serum transferrin receptor, serum ferritin, total iron-binding capacity and transferrin receptor/ferritin log index.

RESULTS

Pre-intervention a cohort of 11 female runners reported inadequate daily dietary iron intake of 10.7 ± 2.7 mg/day, which was associated with overall compromised iron status. Over a third of all participants showed depleted bodily iron stores (serum ferritin <12 μg/L). Pre-intervention macronutrient assessment revealed adequate energy, protein and fibre intakes, whilst total fat and saturated fat intake was above the recommendations at the expense of carbohydrate intake. A 6-week dietary intervention resulted in significantly higher total iron intakes (18.5 mg/day, P < 0.05) and improved iron tissue supply but not enlarged iron stores. Improvements in heamatological indices were associated with compromised baseline iron status, prolonged intervention period and increase in dietary iron intake.

CONCLUSION

Dietary iron interventions using a staple cereal product offer an alternative way of improving dietary iron intake and favourable affecting overall iron status in physically active females.

Improvements in iron status and cognitive function in young women consuming beef or non-beef lunches

Iron status is associated with cognitive performance and intervention trials show that iron supplementation improves mental function in iron-deficient adults. However, no studies have tested the efficacy of naturally iron-rich food in this context. This investigation measured the hematologic and cognitive responses to moderate beef consumption in young women. Participants (n=43; age 21.1±0.4 years) were randomly assigned to a beef or non-beef protein lunch group [3-oz (85 g), 3 times weekly] for 16 weeks. Blood was sampled at baseline, and weeks 8 and 16, and cognitive performance was measured at baseline and week 16. Body iron increased in both lunch groups (p<0.0001), with greater improvement demonstrated in women with lower baseline body iron (p<0.0001). Body iron had significant beneficial effects on spatial working memory and planning speed (p<0.05), and ferritin responders (n=17) vs. non-responders (n=26) showed significantly greater improvements in planning speed, spatial working memory strategy, and attention (p<0.05). Lunch group had neither significant interactions with iron status nor consistent main effects on test performance. These findings support a relationship between iron status and cognition, but do not show a particular benefit of beef over non-beef protein consumption on either measure in young women.

Manganese efflux in Parkinsonism: insights from newly characterized SLC30A10 mutations

Although manganese (Mn) is required for normal cellular function, overexposure to this metal may cause an extrapyramidal syndrome resembling Parkinson's disease (PD). Notably, high whole-blood Mn levels have been reported in patients with idiopathic PD. Because Mn is both essential at low dose and toxic at higher dose; its transport and homeostasis are tightly regulated. Previously, the only protein known to be operant in cellular Mn export was the iron-regulating transporter, ferroportin (Fpn). The causal role for Mn in PD has yet to be fully understood, but evidence of a familial predisposition to PD associated with Mn toxicity is mounting. A recently discovered mutation in SLC30A10 identified its gene product as putatively involved in Mn efflux. Patients with the SLC30A10 mutation display Parkinsonian-like gate disturbances and hypermanganesemia. This review will address Mn transport proteins, the newly discovered SLC30A10 mutations and their implications to Parkinsonism and Mn regulation.