The relative bioavailability in humans of elemental iron powders for use in food fortification

The effect of iron sulfate nanoparticles and their fortified bread on Wistar rats and human cell lines

BACKGROUND

Ferrous sulfate nanoparticles (FSNPs) were synthesized and characterized to mitigate the undesirable effects of ferrous sulfate bulk particles (FSBPs) as a supplement or fortificant in health/food industries.

METHODS

The toxicity of FSNPs and FSBPs was evaluated against AGS, PLC/PRF/5, and HGF1-PI 1 cell lines. Then, Wistar rats were fed three levels of FSNPs and FSBPs fortified-bread. Growth performance, hematological parameters, and histopathological changes in treated rats were assessed after 21 days.

RESULTS

High concentrations of FSNPs (3.125 and 6.25 mM) increased the necrosis of AGS cells. A low level of FSNPs (1.57 mM) did not affect the viability of cells after 72 h. Fibroblasts did not show apoptosis and necrosis after exposing 1.57 mM of FSNPs. In rats, 9 mg elemental iron of FSNPs/day enhanced hemoglobin, PCV, and ferritin values and increased the body weight gain (p < 0.05). FSNPs fortified-bread induced no clinical symptom or histopathological lesion in rats.

CONCLUSION

FSNPs affect cells in a dose-dependent manner. The results indicate that FSNPs at the low level do not have adverse effects on normal fibroblasts and rats. Significant weight gain in rats having a low level of FSNPs compared to the FSBPs indicates the negligible toxicity of FSNPs at low concentrations.

Ensuring the Efficacious Iron Fortification of Foods: A Tale of Two Barriers

Iron fortification of foods has always been a challenge. This is because iron fortification compounds vary widely in relative absorption; because many foods undergo unacceptable changes in color or flavor from the addition of iron; and because many of the iron-fortified foods contain potent inhibitors of iron absorption. These technical barriers have largely been overcome, and efficacious iron-fortified foods, that maintain or improve the iron status of women or children in long-term feeding studies, can be designed. Commercially fortified infant foods are efficacious, and other commercial iron-fortified foods targeted at women and children will provide a useful amount of iron provided the fortification level is adjusted according to the relative absorption of the iron compound. Technologies for the large-scale fortification of wheat and maize flour are also well established, and iron fortification of rice, using the recently developed extruded premix technique, is showing great promise. However, some important knowledge gaps still remain, and further research and development is needed in relation to iron (and iodine)-fortified salt and iron-fortified liquid milk. The usefulness of less-soluble iron compounds, such as ferrous fumarate, to fortify foods for infants and young children in low- and middle-income countries (LMICs) also needs further investigation. A more formidable barrier to efficacious iron-fortified food has been reported in recent years. This is the infection-initiated inflammation barrier, which inhibits iron absorption in response to infection. This barrier is particularly important in LMICs where infections such as malaria and HIV are widespread, and gastrointestinal infections are common due to poor quality water supplies and sanitation. Another source of inflammation in such countries is the high prevalence of obesity in women. Most countries in sub-Saharan Africa have high inflammation which not only decreases the efficacy of iron-fortified and iron-biofortified foods but complicates the monitoring of large-scale iron fortification programs. This is because iron deficiency anemia cannot be differentiated from the more prominent anemia of inflammation and because inflammation confounds the measurement of iron status. There is an urgent need to better quantify the impact of inflammation on the efficacy of iron-fortified foods. However, at present, in LMICs with high inflammation exposure, infection control, cleaner water, improved sanitation, and a decrease in obesity prevalence will undoubtedly have a greater impact on iron status and anemia than the iron fortification of foods.

Bioavailability of iron from novel hydrogen reduced iron powders: Studies in Caco-2 cells and rat model

The bioavailability of iron from elemental iron powders, including hydrogen reduced iron powder (HRIP), is influenced by particle size and surface area. In the present study, we investigated the solubility, bioaccessibility, and bioavailability of iron from novel HRIPs (particle size ≤25 and 38 µm generated at low [LT] and high [HT] temperature), with porous morphology and high surface area, in intestinal Caco-2 cells and in rat models. The acceptability of fortified wheat flour was tested in human volunteers. The iron solubility and ferritin induction in Caco-2 cells were significantly higher from wheat flour fortified with HRIPs compared to electrolytic iron powder (EIP, ≤45 µm size) either in the absence or presence of ascorbic acid. Nevertheless, ferritin induction in Caco-2 cells was significantly higher with FeSO₄ compared to HRIP or EIP. The relative biological value of HRIPs was significantly higher (≤38HT) or similar compared to EIP in rats. However, serum ferritin was significantly higher in rats fed HRIPs than EIP. Further, wheat flour fortified with HRIP was found to be acceptable for consumption. These findings demonstrate higher iron bioavailability from novel HRIPs compared to the reference EIP (≤45 µm) and merits further studies on toxicity and efficacy. PRACTICAL APPLICATION: The use of elemental iron powders for food fortification to alleviate iron deficiency is limited due to its poor bioavailability. The novel hydrogen-reduced elemental iron powders used in this study had higher bioaccessibility and bioavailability compared to reference EIP (≤45 µm) in in vitro and in vivo models, respectively. Further, there were no sensory differences between roti prepared with fortified or unfortified wheat flour. These results suggest that the novel hydrogen reduced elemental iron powders used in the present study are suitable for wheat flour fortification.

Iron Absorption from Iron-Enriched Aspergillus oryzae Is Similar to Ferrous Sulfate in Healthy Female Subjects

BACKGROUND

Iron deficiency anemia (IDA) remains a global health issue, affecting mainly children and adolescent and pregnant women. Because of problems associated with current iron compounds used in both supplementation and fortification areas, there is an emerging interest in new natural iron sources to combat IDA.

OBJECTIVE

The objective of this study was to compare the iron absorption of iron-enriched Aspergillus oryzae [Aspiron (ASP)] with FeSO4 in humans.

METHODS

Iron absorption was assessed using stable isotope and serum iron response methods after oral intake of iron by healthy women in 2 separate studies. In the first study, ASP was intrinsically labelled with 58Fe into a dry form containing 8% iron. Subjects (n = 16, 18-35 y) were randomly assigned to consume liquid semipurified meals labelled with 2 stable iron isotopes, 57FeSO4 (10 mg) and ASP containing 2 mg 58Fe and 8 mg natural abundance iron, in 2 visits. Isotope enrichment was measured 2 wk after the last meal was eaten. In the second study, 17 subjects were randomly assigned to consume a test meal with 3 iron supplements during 3 separate visits: FeSO4, 10 mg Fe, and ASP in 2 iron doses, 10 mg and 20 mg. Changes in serum iron were measured at regular intervals for 4 h after supplementation.

RESULTS

The first study showed that the difference in iron absorption from FeSO4 and ASP was not significant (17.18% ± 14.2% compared to 15.14% ± 12.3%; P = 0.07). The results of the second study suggested that the iron from ASP was released slowly compared to FeSO4 and the area under the curve did not reflect the absorption of ASP iron, but rather the rate of iron release.

CONCLUSIONS

Iron-enriched A. oryzae has high relative bioavailability and may cause lower iron surges into the blood compared to FeSO4.

Mechanisms of Iron Uptake from Ferric Phosphate Nanoparticles in Human Intestinal Caco-2 Cells

Food fortification programs to reduce iron deficiency anemia require bioavailable forms of iron that do not cause adverse organoleptic effects. Rodent studies show that nano-sized ferric phosphate (NP-FePO₄) is as bioavailable as ferrous sulfate, but there is controversy over the mechanism of absorption. We undertook in vitro studies to examine this using a Caco-2 cell model and simulated gastrointestinal (GI) digestion. Supernatant iron concentrations increased inversely with pH, and iron uptake into Caco-2 cells was 2–3 fold higher when NP-FePO₄ was digested at pH 1 compared to pH 2. The size and distribution of NP-FePO₄ particles during GI digestion was examined using transmission electron microscopy. The d50 of the particle distribution was 413 nm. Using disc centrifugal sedimentation, a high degree of agglomeration in NP-FePO₄ following simulated GI digestion was observed, with only 20% of the particles ≤1000 nm. In Caco-2 cells, divalent metal transporter-1 (DMT1) and endocytosis inhibitors demonstrated that NP-FePO₄ was mainly absorbed via DMT1. Small particles may be absorbed by clathrin-mediated endocytosis and micropinocytosis. These findings should be considered when assessing the potential of iron nanoparticles for food fortification.

Trace Element Concentrations in Human Tissues of Death Cases Associated With Secondary Infection and MOF After Severe Trauma

Proper trace element level is crucial for the organs in maintaining normal physiological functions. Multiple organ failure (MOF) might be added to critically ill patients due to a lack of trace elements. Alterations of trace element levels in brain, heart, liver, and kidney after severe trauma, however, have been little studied so far. In this study, tissue samples of the frontal cortex of the brain, interventricular septum of the heart, right lobe of the liver, and upper pole of the kidney were obtained from forensic autopsies, of which 120 cases died during the 5th to 15th day of hospitalization, whereas the trauma death group and 43 cases immediately died due to severe craniocerebral trauma as the control group. Copper (Cu), iron (Fe), zinc (Zn), and selenium (Se) were quantified by inductively coupled plasma atomic emission spectrophotometry (ICP-AES). Cu, Fe, Zn, and Se concentrations in the brain, heart, liver, and kidney in the trauma group decreased dramatically (p<0.05) compared to the control group. The incidence of secondary infection and multiple organ failure (MOF) in the trauma death group were 78.33 and 29.17%, respectively. The concentrations of all elements exhibited a significant correlation with secondary infection and MOF (p<0.01). Our data suggest that low concentrations of Cu, Fe, Zn, and Se in pivotal organs may contribute to the incidence of secondary infection and MOF after severe trauma, which to some extent results in death.

Analysis of blood trace elements and biochemical indexes levels in severe craniocerebral trauma adults with Glasgow Coma Scale and injury severity score

We aimed to investigate the correlation between the Glasgow Coma Scale (GCS), the injury severity score (ISS) and serum levels of trace elements (TE) in severe trauma patients to analyze alteration of the levels of trace elements and serum biochemical indexes in the period of admission from 126 adult cases of severe brain trauma with traffic accidents. Multi-trace elements for patients in the trauma-TE groups were used. The results indicated that all patients presented an acute trace elements deficiency syndrome (ATEDs) after severe trauma, and the correlation between ISS and serum levels of Fe, Zn, and Mg was significant. Compared to the normal control group, levels of the trace elements in serum were significantly decreased after trauma, suggesting that enhancement of immunity to infection and multiple organ failure (MOF) via the monitoring and supplement of trace elements will be a good strategy to severe traumatic patients in clinics.

Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors

BACKGROUND

Iron deficiency is a significant cause of deferral in people wishing to donate blood. If iron removed from the body through blood donation is not replaced, then donors may become iron deficient. All donors are screened at each visit for low haemoglobin (Hb) levels. However, some deferred blood donors do not return to donate. Deferred first-time donors are even less likely to return. Interventions that reduce the risk of provoking iron deficiency and anaemia in blood donors will therefore increase the number of blood donations. Currently, iron supplementation for blood donors is not a standard of care in many blood services. A systematic review is required to answer specific questions regarding the efficacy and safety of iron supplementation in blood donors.

OBJECTIVES

To assess the efficacy and safety of iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors.

SEARCH METHODS

We ran the search on 18 November 2013. We searched Cochrane Injuries Group Specialised Register, CENTRAL, PubMed, MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL (EBSCO Host) and six other databases. We also searched clinical trials registers and screened guidelines reference lists.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing iron supplementation versus placebo or control, oral versus parenteral iron supplementation, iron supplementation versus iron-rich food supplements, and different doses, treatment durations and preparations of iron supplementation in healthy blood donors. Autologous blood donors were excluded.

DATA COLLECTION AND ANALYSIS

We combined data using random-effects meta-analyses. We evaluated heterogeneity using the I(2) statistic; we explored considerable heterogeneity (I(2) > 75%) in subgroup analyses. We carried out sensitivity analyses to assess the impact of trial quality on the results.

MAIN RESULTS

Thirty RCTs (4704 participants) met the eligibility criteria, including 19 comparisons of iron supplementation and placebo or control; one comparison of oral and parenteral iron supplementation; four comparisons of different doses of iron supplementation; one comparison of different treatment durations of iron supplementation; and 12 comparisons of different iron supplementation preparations.Many studies were of low or uncertain methodological quality and therefore at high or uncertain risk of bias. We therefore rated the quality of the evidence for our outcomes as moderate. There was a statistically significant reduction in deferral due to low haemoglobin in donors who received iron supplementation compared with donors who received no iron supplementation, both at the first donation visit after commencement of iron supplementation (risk ratio (RR) 0.34; 95% confidence interval (CI) 0.21 to 0.55; four studies; 1194 participants; P value < 0.0001) and at subsequent donations (RR 0.25; 95% CI 0.15 to 0.41; three studies; 793 participants; P value < 0.00001). Supplementation also resulted in significantly higher haemoglobin levels (mean difference (MD) 2.36 g/L; 95% CI 0.06 to 4.66; eight studies; 847 participants, P value =0.04), and iron stores, including serum ferritin (MD 13.98 ng/mL; 95% CI 8.92 to 19.03; five studies; 640 participants; P value < 0.00001) and transferrin saturation (MD 3.91%; 95% CI 2.02 to 5.80; four studies; 344 participants; P value < 0.0001) prior to further donation. The differences were maintained after subsequent donation(s).Adverse effects were widely reported and were more frequent in donors who received iron supplementation (RR 1.60; 95% CI 1.23 to 2.07; four studies; 1748 participants; P value = 0.0005). Adverse effects included constipation, diarrhoea, nausea, vomiting and taste disturbances, and some participants stopped treatment due to side effects.

AUTHORS' CONCLUSIONS

There is moderate quality evidence that rates of donor deferral due to low haemoglobin are considerably less in those taking iron supplements compared with those without iron supplementation, both at the first donation visit and at subsequent donation. Iron-supplemented donors also show elevated haemoglobin and iron stores. These beneficial effects are balanced by more frequent adverse events in donors who receive iron supplementation than in those who do not; this is likely to limit acceptability and compliance. The long-term effects of iron supplementation without measurement of iron stores are unknown. These considerations are likely to preclude widespread use of iron supplementation by tablets. Blood services may consider targeted use of supplementation in those at greatest risk of iron deficiency, personalised donation intervals and providing dietary advice.

Differences in Circulating Non-Transferrin-Bound Iron after Oral Administration of Ferrous Sulfate, Sodium Iron EDTA, or Iron Polymaltose in Women with Marginal Iron Stores

Background

The adverse interactions between iron supplements and malaria have driven the assessment of new therapeutic options for anemia prophylaxis in areas holoendemic for falciparum malaria.

Objective

To determine the responses of circulating non-transferrin-bound iron (NTBI) and plasma iron to three different oral iron compounds—ferrous sulfate, sodium iron ethylenediaminetetraacetate (NaFeEDTA), and iron polymaltose (IPM)—in women with marginal iron stores.

Methods

Serum samples from 10 Guatemalan women with marginal iron stores were collected every 90 minutes over a period of 270 minutes, after the individually randomized administration of 100 mg of iron from each of the three studied iron compounds or water alone. Serum iron concentration was quantified by the ferrozine method, and circulating NTBI concentration was determined with a fluorometric competitive binding assay. Kinetic responses and maximal cumulative changes in serum concentrations of iron and NTBI were compared between the four treatments. Comparison was made with data from the same protocol in iron-adequate men.

Results

The serum iron and NTBI responses to ferrous sulfate were significantly greater than those to water and the other two iron compounds. Serum iron responses to IPM did not differ from those to water alone.

Conclusions

The administration of the two “slow-release” iron compounds, NaFeEDTA and IPM, resulted in a highly significant suppression of the appearance of NTBI in the circulation in the postsupplement period. These two bioavailable forms of iron supplement could represent a safe option for supplementation in malarial areas. The slope of the iron—NTBI relationship is steeper in men than in women.

Effect of iron-fortified foods on hematologic and biological outcomes: systematic review of randomized controlled trials

BACKGROUND

The utility of iron fortification of food to improve iron deficiency, anemia, and biological outcomes is not proven unequivocally.

OBJECTIVES

The objectives were to evaluate 1) the effect of iron fortification on hemoglobin and serum ferritin and the prevalence of iron deficiency and anemia, 2) the possible predictors of a positive hemoglobin response, 3) the effect of iron fortification on zinc and iron status, and 4) the effect of iron-fortified foods on mental and motor development, anthropometric measures, and infections.

DESIGN

Randomized and pseudorandomized controlled trials that included food fortification or biofortification with iron were included.

RESULTS

Data from 60 trials showed that iron fortification of foods resulted in a significant increase in hemoglobin (0.42 g/dL; 95% CI: 0.28, 0.56; P < 0.001) and serum ferritin (1.36 μg/L; 95% CI: 1.23, 1.52; P < 0.001), a reduced risk of anemia (RR: 0.59; 95% CI: 0.48, 0.71; P < 0.001) and iron deficiency (RR: 0.48; 95% CI: 0.38, 0.62; P < 0.001), improvement in other indicators of iron nutriture, and no effect on serum zinc concentrations, infections, physical growth, and mental and motor development. Significant heterogeneity was observed for most of the evaluated outcomes. Sensitivity analyses and meta-regression for hemoglobin suggested a higher response with lower trial quality (suboptimal allocation concealment and blinding), use of condiments, and sodium iron edetate and a lower response when adults were included.

CONCLUSION

Consumption of iron-fortified foods results in an improvement in hemoglobin, serum ferritin, and iron nutriture and a reduced risk of remaining anemic and iron deficient.

The neglected significance of "antioxidative stress"

Oxidative stress arises when there is a marked imbalance between the production and removal of reactive oxygen species (ROS) in favor of the prooxidant balance, leading to potential oxidative damage. ROSs were considered traditionally to be only a toxic byproduct of aerobic metabolism. However, recently, it has become apparent that ROS might control many different physiological processes such as induction of stress response, pathogen defense, and systemic signaling. Thus, the imbalance of the increased antioxidant potential, the so-called antioxidative stress, should be as dangerous as well. Here, we synthesize increasing evidence on “antioxidative stress-induced” beneficial versus harmful roles on health, disease, and aging processes. Oxidative stress is not necessarily an un-wanted situation, since its consequences may be beneficial for many physiological reactions in cells. On the other hand, there are potentially harmful effects of “antioxidative stress,” especially in the cases of overconsumption of synthetic antioxidants. Antioxidants can neutralize ROS and decrease oxidative stress; however, this is not always beneficial in regard to disease formation or progression (of, e.g., cancer) or for delaying aging.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Critical review of strategies to prevent and control iron deficiency in children

Iron deficiency is prevalent in infants and young children in developing countries and is associated with adverse developmental outcomes. The routine provision of additional iron by food fortification or the use of iron supplements is generally recommended. The wisdom of this approach in regions where the transmission of Plasmodium falciparum malaria is perennial and intense is now being questioned, because a large trial in Pemba, Tanzania, demonstrated an increased risk of serious morbidity among children under the age of 3 years who were given routine daily iron and folic acid supplements. However, the results of a concurrent substudy suggest that the untoward effects occurred in children who were not iron deficient, and that iron deficiency itself is associated with an increased risk of severe morbidity that can be reduced by iron and folic acid supplementation. There is an urgent need for additional research to confirm these observations, to establish the role, if any, of the concurrent folic acid supplementation, to evaluate the risk of alternative methods for delivering iron that, on theoretical grounds, could be safer, and to establish the programmatic feasibility of targeting iron fortificants or supplements to iron-deficient children. It is evident that a single strategy for ensuring adequate iron nutrition in young children in different parts of the world is no longer likely to be satisfactory. Moreover, integration with other health-related strategies, particularly malaria control programs, will be essential.

The importance of bioavailability of dietary iron in relation to the expected effect from iron fortification

BACKGROUND

The most common method of combating iron deficiency is iron fortification, especially in developing countries. However, few studies have shown a significant effect on iron status following iron fortification of low bioavailability diets.

OBJECTIVE

To investigate how iron fortification and dietary modifications affect iron absorption and rates of changes in iron stores.

METHODS

Research has made it possible to predict both iron absorption and the effects of iron fortification and diet modifications on iron stores using recently developed algorithms. Iron absorption and rate of change in iron stores were calculated from nine diets representing a broad range of iron bioavailability and iron contents. The calculations were related to the main target group for iron fortification, that is, women of reproductive age having empty stores but normal haemoglobin concentrations.

RESULTS

As the only measure, iron fortification has practically no effect on iron status if the original diet has low bioavailability. However, after dietary modifications such a diet shows a positive effect on iron stores. The combined action of fortification (6 mg/day) and modest bioavailability changes in a low bioavailability diet results approximately in 40 and 70% greater increases in iron stores than through iron fortification or dietary modification alone.

CONCLUSIONS

It is difficult to achieve good effects on iron status from iron fortification as the only measure if the diet has low bioavailability. Both dietary modifications as well as iron fortification are required to improve effectively the iron status of a population.

Fermentation and lactic acid addition enhance iron bioavailability of maize

Maize is one of the most important cereal crops for human consumption, yet it is of concern due to its low iron bioavailability. The objective of this study was to determine the effects of processing on iron bioavailability in common maize products and elucidate better processing techniques for enhancing iron bioavailability. Maize products were processed to represent different processing techniques: heating (porridge), fermentation (ogi), nixtamalization (tortillas), and decortication (arepas). Iron and phytate contents were evaluated. Iron bioavailability was assessed using the Caco-2 cell model. Phytate content of maize products was significantly reduced by decortication (25.6%, p = 0.003) and nixtamalization (15%, p = 0.03), and iron content was reduced by decortication (29.1%, p = 0.002). The relative bioavailability (RBA, compared to 100% bioavailability of porridge with FeSO4) of ogi was significantly higher than that of other products when fortified with FeSO4 (p < 0.001) or reduced iron (p < 0.001). Addition of lactic acid (6 mg/g of maize) significantly increased iron solubility and increased bioavailability by about 2-fold (p < 0.01), especially in tortillas. The consumer panel results showed that lactic acid addition does not significantly affect the organoleptic characteristics of tortillas and arepas (p = 0.166 and 0.831, respectively). The results suggest that fermentation, or the addition of small amounts of lactic acid to unfermented maize products, may significantly improve iron bioavailability. Lactic acid addition may be more feasible than the addition of highly bioavailable but expensive fortificants. This approach may be a novel means to increase the iron bioavailability of maize products to reduce the incidence of iron deficiency anemia.

Capturing the onset of the common cold and its effects on iron absorption

Hypoferremia is a well-known response to infections and inflammatory disorders. It seems to be managed by the key mediator of iron kinetics, hepcidin. There are several studies on induced-acute phase reactions. However, to our best knowledge there are no previous published reports on the outbreak of a common cold and its initial effect on iron kinetics. The objective of this case report is to describe such an observation. From an apparently healthy state in the morning we observed, in a 28-year-old male, every hour for 6 h the outbreak of a common cold and the modulations in the levels of serum iron (S-Fe) and interleukin-6 (IL-6). Despite a 100 mg oral iron loading there was a substantial reduction in S-Fe, which seemed to precede the IL-6 peak. Interestingly, this observed succession is in conflict with the proposed infection chain of order in which IL-6 stimulates hepcidin induction.

Impact of daily consumption of iron fortified ready-to-eat cereal and pumpkin seed kernels (Cucurbita pepo) on serum iron in adult women

Iron deficiency, anemia, is the most prevalent nutritional problem in the world today. The objective of this study was to consider the effectiveness of consumption of iron fortified ready-to-eat cereal and pumpkin seed kernels as two sources of dietary iron on status of iron nutrition and response of hematological characteristics of women at reproductive ages. Eight healthy female, single or non pregnant subjects, aged 20-37 y consumed 30 g of iron fortified ready-to-eat cereal (providing 7.1 mg iron/day) plus 30 g of pumpkin seed kernels (providing 4.0 mg iron/day) for four weeks. Blood samples collected on the day 20 of menstrual cycles before and after consumption and indices of iron status such as reticulocyte count, hemoglobin (Hb), hematocrit (Ht), serum ferritin, iron, total iron-binding capacity (TIBC), transferrin and transferrin saturation percent were determined. Better response for iron status was observed after consumption period. The statistical analysis showed a significant difference between the pre and post consumption phase for higher serum iron (60 +/- 22 vs. 85 +/- 23 ug/dl), higher transferrin saturation percent (16.8 +/- 8.0 vs. 25.6 +/- 9.0%), and lower TIBC (367 +/- 31 vs. 339 +/- 31 ug/dl). All individuals had higher serum iron after consumption. A significant positive correlation (r=0.981, p=0.000) between the differences in serum iron levels and differences in transferrin saturation percentages and a significant negative correlation (r=-0.916, p<0.001) between the differences in serum iron levels and differences in TIBC was found, as well. Fortified foods contribute to maintaining optimal nutritional status and minimizing the likelihood of iron insufficiencies and use of fortified ready-to-eat cereals is a common strategy. The results showed that adding another food source of iron such as pumpkin seed kernels improves the iron status. Additional and longer studies using these two food products are recommended to further determine the effect of iron fortification on iron nutrition and status among the target population, and mainly in young children, adolescents, women of reproductive ages and pregnant women.

Effect of bread baking on the bioavailability of hydrogen-reduced iron powder added to unenriched refined wheat flour

Elemental iron powders are widely used to fortify flour and other cereal products. Our objective was to test the hypothesis that baking enhances the bioavailability of elemental iron powders by oxidizing Fe(0) to Fe(2+) or Fe(3+). An in vitro digestion/Caco-2 cell culture model and a piglet model were used to measure bioavailability. Bread flour, either unfortified or fortified with hydrogen-reduced (HR) iron powder or FeSO(4) (300 mg Fe/kg flour), was baked into bread. For the in vitro studies, bread samples were treated with pepsin at pH 2, 3, 4, 5, 6, or 7 and subsequently incubated with pancreatic enzymes at pH 7 in a chamber positioned above monolayers of cultured Caco-2 cells. Ferritin formation in the cells was used as an index of iron bioavailability. Ferritin formation in cells fed HR Fe bread was similar to cells fed FeSO(4) bread when the peptic digestion was conducted at a pH 2 but lower when the peptic phase was conducted at pH 3, 4, 5, 6, or 7 (P < 0.05). Pig diets containing 35% dried bread were prepared and fed to cross-bred (Hampshire x Landrace x Yorkshire) anemic pigs in two studies. The rate of increase in hemoglobin Fe over the feeding period was used to calculate relative biological value (RBV), an index of iron bioavailability. In the first pig study, RBV of HR Fe added to flour prior to baking was 47.9% when compared to FeSO(4) fortified flour (P < 0.05). In the second pig study, a third treatment consisting of unfortified bread with HR iron added during diet mixing (after bread baking) was included. RBVs of the HR Fe diet (Fe added after baking) and HR Fe diet (Fe added before baking) were 40.1% and 53.5%, respectively, compared to the FeSO(4) diet. Differences in RBV between the HR Fe (before and after baking) and FeSO(4) (before baking) treatment groups were significant, but the difference between the before and after HR treatment groups was not significant. We conclude that bread baking does not enhance the bioavailability of elemental iron powders.

An irradiated electrolytic iron fortificant is poorly absorbed by humans and is less responsive than FeSO4 to the enhancing effect of ascorbic acid

Despite extensive use, information on the bioavailability of elemental iron powders to humans, as influenced by dose and other dietary constituents, is limited. Three experiments were conducted to assess the absorption of electrolytic iron powder relative to FeSO4, as affected by iron dose and by ascorbic or phytic acid. Iron absorption by 56 volunteers was measured from a farina cereal breakfast radiolabeled with 59FeSO4 or an electrolytic 55Fe powder irradiated by neutron activation. Absorption was determined from whole-body counting (59Fe) and blood isotope incorporation 2 wk later. Absorption of iron from the irradiated electrolytic powder was 5-15% that of FeSO4. Ascorbic acid (approximately 160 mg) enhanced iron absorption from FeSO4 by almost 4-fold but only doubled absorption from electrolytic iron (P for interaction < 0.01). Phytic acid from wheat bran inhibited iron absorption from FeSO4 and electrolytic iron by 73 and 50%, respectively (P for interaction, NS). Compared with 3 mg, a 20-mg dose reduced fractional absorption from FeSO4, but not electrolytic iron (P for interaction < 0.0001). Despite a much higher bioavailability (50% relative to FeSO4) of this same electrolytic iron when tested previously in a pig model, the bioavailability of the irradiated electrolytic iron was poor in humans. The diminished influence of ascorbic acid on the absorption of less soluble iron sources such as elemental iron powders may be an important consideration when choosing iron fortificants.