Iron bioavailability of a casein-based iron fortificant compared with that of ferrous sulfate in whole milk: a randomized trial with a crossover design in adult women

Influence of Dietary Fibre and Protein Fractions on the Trace Element Bioaccessibility of Turnip Tops (Brassica rapa) Growing under Mediterranean Conditions

The objective of this work was to study the influence of three dietary fibre fractions (pectin, gum arabic and cellulose) and three protein fractions (casein, lactalbumin and soy) on the trace element bioaccessibility (Fe, Mn, Ni, Se and Zn) of turnip tops (B. rapa subsp. Rapa) growing under Mediterranean conditions. Then, it aimed to promote the use of this vegetable not only for direct fresh consumption but also as a main ingredient in the development of food mixtures. The results showed that soluble fibre fractions, such as pectin and gum arabic, can enhance the bioaccessibility of trace elements, such as Fe, Mn, Se and Zn. This effect was not proved for cellulose (an insoluble fibre fraction), in which, at best, no bioaccessibility effect was observed. Regarding the protein fractions, with the exception of Se, caseins and lactalbumin had a neutral effect on improving the trace element bioaccessibility. This did not hold true for soy protein, in which a considerable improvement in the bioaccessibility of Fe, Mn, Se and Zn was determined.

Folate-assisted targeted photocytotoxicity of red-light-activable iron(III) complex co-functionalized gold nanoconjugates (Fe@FA-AuNPs) against HeLa and triple-negative MDA-MB-231 cancer cells

Photo-redox chemistry resulting from ligand to metal charge transfer in red-light-activable iron(III) complexes could be a potent strategic tool for next-generation photochemotherapeutic applications. Herein, we developed an iron(III) complex and folate co-functionalized gold nanoconjugate (Fe@FA-AuNPs) and thoroughly characterized it with NMR, ESI MS, UV-visible, EPR, EDX, XPS, powder X-ray diffraction, TEM and DLS studies. There was a remarkable shift in the SPR band of AuNPs to 680 nm, and singlet oxygen (1O2) and hydroxyl radicals were potently generated upon red-light activation, which were probed by UV-visible and EPR spectroscopic assays. Cellular uptake studies of the nanoconjugate (Fe@FA-AuNPs) revealed significantly higher uptake in folate(+) cancer cells (HeLa and MDA-MB-231) than folate(-) (A549) cancer cells or normal cells (HPL1D), indicating the targeting potential of the nanoconjugate. Confocal imaging indicated primarily mitochondrial localization. The IC50 values of the nanoconjugate determined from a cell viability assay in HeLa, MDA-MB-231, and A549 cells were 27.83, 39.91, and 69.54 μg mL-1, respectively in red light, while in the dark the values were >200 μg mL-1; the photocytotoxicity was correlated with the cellular uptake of the nanoconjugate. The nanocomposite exhibited similar photocytotoxicity (IC50 in red light, 37.35 ± 8.29 μg mL-1 and IC50 in the dark, >200 μg mL-1). Mechanistic studies revealed that intracellular generation of ROS upon red-light activation led to apoptosis in HeLa cells. Scratch-wound-healing assays indicated the inhibition of the migration of MDA-MB-231 cells treated with the nanoconjugate and upon photo-activation. Overall, the nanoconjugate has emerged as a potent tool for next-generation photo-chemotherapeutics in the clinical arena of targeted cancer therapy.

Factors affecting iron absorption and the role of fortification in enhancing iron levels

Iron is an important micronutrient required for a number of biological processes including oxygen transport, cellular respiration, the synthesis of nucleic acids and the activity of key enzymes. The World Health Organization has recognised iron deficiency as the most common nutritional deficiency globally and as a major determinant of anaemia. Iron deficiency anaemia affects 40% of all children between the ages of 6 and 59 months, 37% of mothers who are pregnant and 30% of women between the ages of 15 and 49 years worldwide. Dietary iron exists in two main forms known as haem iron and non-haem iron. Haem iron is obtained from animal sources such as meat and shows higher bioavailability than non-haem iron, which can be obtained from both plant and animal sources. Different components in food can enhance or inhibit iron absorption from the diet. Components such as meat proteins and organic acids increase iron absorption, while phytate, calcium and polyphenols reduce iron absorption. Iron levels in the body are tightly regulated since both iron overload and iron deficiency can exert harmful effects on human health. Iron is stored mainly as haemoglobin and as iron bound to proteins such as ferritin and hemosiderin. Iron deficiency affects individuals at increased risk due to factors such as age, pregnancy, menstruation and various diseases. Different solutions for iron deficiency are applied at individual and community levels. Iron supplements and intravenous iron can be used to treat individuals with iron deficiency, while various types of iron-fortified foods and biofortified crops can be employed for larger communities. Foods such as rice, flour and biscuits have been used to prepare fortified iron products. However, it is important to ensure the fortification process does not exert significant negative effects on organoleptic properties and the shelf life of the food product.

An active new formulation of iron carried by aspartyl casein for iron-deficiency anemia: results of the ACCESS trial

Oral iron supplementation is the cornerstone for the management of iron-deficiency anemia. A new oral formulation of iron conjugated with N-aspartyl-casein (Fe-ASP) (Omalin®, Uni-Pharma) is studied in the ACCESS double-blind, double-dummy randomized clinical trial; 60 patients were randomized to 12-week oral treatment twice every day either with oral ferrous sulfate (FeSO₄) delivering 47 mg elementary iron or oral Fe-ASP delivering 40 mg elementary iron. Participants had hemoglobin less than 10 g/dl, decreased red blood cell (RBC) count, and ferritin lower than 30 ng/ml; patients with a medical history of malignancy were excluded. The primary endpoint was the increase of Hb in the first 4 weeks of treatment, and the study was powered for non-inferiority. A new score of global improvement was introduced where all participants were given one point for any at least 10% increase of Hb, RBC, and reticulocytes. At week 4, the mean (SE) change of Hb was 0.76 g/dl in the FeSO₄ group and 0.83 g/dl in the Fe-ASP group (p: 0.876). The odds for worse allocation of the global score were 0.35 in the Fe-ASP group compared to the FeSO₄ group. Patients in the Fe-ASP group experienced a significant decrease in the number of IDA-related physical signs by week 4. No differences were found between the two groups in any of the patient-reported outcomes of fatigue and of gastrointestinal adverse events either at week 4 or at week 12. ACCESS is the most recent clinical trial showing the non-inferiority of Fe-ASP to FeSO₄ for the primary endpoint of the Hb change.

Food fortification strategies to deliver nutrients for the management of iron deficiency anaemia

A rising trend in the global prevalence of anaemia is still prevailing. To combat micronutrient deficiencies, World Health Organisation/Food Agriculture Organisation (2006) guidelines recommended four chief strategies - supplementation, fortification, nutrition education and dietary diversity. Of the four strategies, food fortification has been considered as the most efficacious and economical approach. However, it is the directives themselves that highlight two major bottlenecks associated with conventional fortification - uniform dissemination of the fortifier in food vehicle that mostly include staple foods, and internal and external compliance evaluation of fortification regulations and standards by the producers. As a result, researchers envisaged a new strategy - Food-to-food fortification that complements conventional fortification. This strategy involves fortification of food vehicles with nutrient-rich food-based fortifiers. The major advantage of utilising food-based fortifiers is that they hold the potential of enhancing the bioavailability of the fortified food and providing additional nutrients and thus, resulting in dietary diversification. It also facilitates the utilisation of underutilised crops as food-based fortifiers. Underutilised crops have been recognised as potential beneficial food source accounting to their nutritional, ecological, and fiscal benefits. This review paper delves into the strengths and shortcomings of conventional iron fortification. It delineates the concept of food-to-food fortification, while precisely discussing about the best practices to be followed to address the possible challenges associated with this strategy. It also promotes the utilisation of underutilised iron rich foods to develop fortified foods and avert global food insecurity. Furthermore, it provides a summary of the studies conducted around the world to develop fortified foods using iron compounds and iron-rich foods, and to investigate their efficacy in managing iron deficiency anaemia.

Safety of iron milk proteinate as a novel food pursuant to Regulation (EU) 2015/2283 and bioavailability of iron from this source in the context of Directive 2002/46/EC

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on iron milk proteinate as a novel food (NF) pursuant to Regulation (EU) 2015/2283 and to address the bioavailability of iron from this source in the context of Directive 2002/46/EC. The NF is a complex of iron, casein and phosphate, which is produced from iron salts (i.e. ferric chloride or ferric sulfate), sodium caseinate and potassium orthophosphate. The NF is proposed by the applicant to be used as a source of iron, of which the NF contains 2-4%. The applicant intends to market the NF as an ingredient in a number of food categories; in food supplements, in total diet replacement for weight control and in foods for special medical purposes. The Panel considers that, taking into account the composition of the NF and the proposed conditions of use, consumption of the NF is not nutritionally disadvantageous. The studies provided for ADME and bioavailability indicate that iron from the NF is bioavailable. Overall, the evidence indicates that upon ingestion the NF undergoes digestion into small peptides to yield iron-bound caseinophosphopeptides that are normal constituents of the human diet, and that the iron from the NF does not bypass the homeostatic control of iron as a nutrient. The Panel concludes that the NF, iron milk proteinate, is safe under the proposed conditions of use. The Panel also concludes that the NF is a source from which iron is bioavailable.

Iron Bioavailability from Ferrous Ammonium Phosphate, Ferrous Sulfate, and Ferric Pyrophosphate in an Instant Milk Drink-A Stable Isotope Study in Children

Ferrous ammonium phosphate (FAP) is an iron salt that has been developed for the fortification of food matrices sensitive to color and flavor changes. The objective of the study was to measure iron absorption from FAP in young children and compare it to a previous evaluation of FAP in young women. A double-blind randomized crossover study with two parallel arms was used to evaluate the iron absorption from FAP added to reconstituted milk powder in comparison to that from ferrous sulfate (FeSO4) and ferric pyrophosphate (FePP). Iron absorption was measured in 39 children aged 3- to 6-years-old using erythrocyte incorporation of stable Fe isotopes (57Fe, 58Fe). The geometric mean iron absorption in iron replete children from FAP, FeSO4 and FePP from milk was 8.3%, 7.6% and 2.1%, respectively. Iron absorption from FAP and FeSO4 fortified milk was not significantly different (p = 0.199); however, it was significantly higher than from FePP fortified milk (p < 0.001). Iron bioavailability from FAP and FePP relative to FeSO4 (relative bioavailability (RBV)) was 110% and 33%, respectively. The RBV of FAP (110%) in iron replete children was higher than previously reported RBV (71%) in mainly iron deficient women. The difference in iron status between the children and women in the respective studies may explain the different RBV values and is discussed.

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.

New approaches, bioavailability and the use of chelates as a promising method for food fortification

Food fortification has been used for many years to combat micronutrient deficiencies; the main challenge with food fortification is the combination of a bioavailable, affordable fortificant with the best (food) vehicle as a carrier to reach at-risk populations. This paper considers mineral deficiencies, especially iron, food fortification, target populations, and the use of chelates in food fortification, as well as different types of mineral-chelate complexes, advantages and limitations of previous trials, methods used for analysis of these complexes, bioavailability of minerals, factors influencing it, and methods particularly those in vitro for predicting outcomes. Three innovative methods (encapsulation, nanoparticulation, and chelation) were explored, which aim to overcome problems associated with conventional fortification, especially those affecting organoleptic properties and bioavailability; but often lead to the emergence of new limitations (for example instability, impracticality and high costs) requiring further research.

Impact of Ascorbic Acid on the In Vitro Iron Bioavailability of a Casein-Based Iron Fortificant

A new iron–casein complex (ICC) has been developed for iron (Fe) fortification of dairy matrices. The objective was to assess the impact of ascorbic acid (AA) on its in vitro bioavailability in comparison with ferrous sulfate (FeSO₄) and ferric pyrophosphate (FePP). A simulated digestion coupled with the Caco-2 cell culture model was used in parallel with solubility and dissociation tests. Under diluted acidic conditions, the ICC was as soluble as FeSO₄, but only part of the iron was found to dissociate from the caseins, indicating that the ICC was an iron chelate. The Caco-2 cell results in milk showed that the addition of AA (2:1 molar ratio) enhanced iron uptake from the ICCs and FeSO₄ to a similar level (p = 0.582; p = 0.852) and to a significantly higher level than that from FePP (p < 0.01). This translated into a relative in vitro bioavailability to FeSO₄ of 36% for FePP and 114 and 104% for the two ICCs. Similar results were obtained from water. Increasing the AA to iron molar ratio (4:1 molar ratio) had no additional effect on the ICCs and FePP. However, ICC absorption remained similar to that from FeSO₄ (p = 0.666; p = 0.113), and was still significantly higher than that from FePP (p < 0.003). Therefore, even though iron from ICC does not fully dissociate under gastric digestion, iron uptake suggested that ICCs are absorbed to a similar amount as FeSO₄ in the presence of AA and thus provide an excellent source of iron.

The Central Role of Iron in Human Nutrition: From Folk to Contemporary Medicine

Iron is a fundamental element in human history, from the dawn of civilization to contemporary days. The ancients used the metal to shape tools, to forge weapons, and even as a dietary supplement. This last indication has been handed down until today, when martial therapy is considered fundamental to correct deficiency states of anemia. The improvement of the martial status is mainly targeted with dietary supplements that often couple diverse co-factors, but other methods are available, such as parenteral preparations, dietary interventions, or real-world approaches. The oral absorption of this metal occurs in the duodenum and is highly dependent upon its oxidation state, with many absorption influencers possibly interfering with the intestinal uptake. Bone marrow and spleen represent the initial and ultimate step of iron metabolism, respectively, and the most part of body iron circulates bound to specific proteins and mainly serves to synthesize hemoglobin for new red blood cells. Whatever the martial status is, today’s knowledge about iron biochemistry allows us to embrace exceedingly personalized interventions, which however owe their success to the mythical and historical events that always accompanied this metal.