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

Ascorbyl palmitate/DSPE-PEG nanocarriers for oral iron delivery: preparation, characterisation and in vitro evaluation

The objective of this study was to encapsulate iron in nanocarriers formulated with ascorbyl palmitate and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine polyethylene glycol (DSPE-PEG) for oral delivery. Blank and iron (Fe) loaded nanocarriers were prepared by a modified thin film method using ascorbyl palmitate and DSPE-PEG. Surface charge of the nanocarriers was modified by the inclusion of chitosan (CHI) during the formulation process. Blank and iron loaded ascorbyl palmitate/DSPE nanocarriers were visualised by transmission electron microscopy (TEM) and physiochemical characterisations of the nanocarriers carried out to determine the mean particle size and zeta potential. Inclusion of chitosan imparted a net positive charge on the nanocarrier surface and also led to an increase in mean particle size. Iron entrapment in ascorbyl palmitate-Fe and ascorbyl palmitate-CHI-Fe nanocarriers was 67% and 76% respectively, suggesting a beneficial effect of chitosan on nanocarrier Fe entrapment. Iron absorption was estimated by measuring Caco-2 cell ferritin formation using ferrous sulphate as a reference standard. Iron absorption from ascorbyl palmitate-Fe (592.17±21.12 ng/mg cell protein) and ascorbyl palmitate-CHI-Fe (800.12±47.6 ng/mg, cell protein) nanocarriers was 1.35-fold and 1.5-fold higher than that from free ferrous sulphate, respectively (505.74±23.73 ng/mg cell protein) (n=6, p<0.05). This study demonstrates for the first time preparation and characterisation of iron loaded ascorbyl palmitate/DSPE PEG nanocarriers, and that engineering of the nanocarriers with chitosan leads to a significant augmentation of iron absorption.

Iron supplementation of breastfed infants

Reported here are three studies performed with the objective of finding ways to improve the iron status of breastfed infants and to prevent iron deficiency (ID). Participating infants were exclusively breastfed until 4 months of age; thereafter, they could receive complementary foods and, in some studies, supplemental formula. In the first study, infants were given medicinal iron between the ages of 1 and 5.5 months. During this period, iron status improved and ID was prevented; however, these benefits did not continue after the intervention ceased. In the second study, infants received medicinal iron or an equivalent amount of iron from an iron-fortified cereal between the ages of 4 and 9 months. Again, iron supplementation largely prevented ID from occurring, while non-anemic ID and ID anemia occurred in the control group as well as in the intervention groups before the intervention began. In the third study, infants received dry cereals fortified with electrolytic iron or with ferrous fumarate between the ages of 4 and 9 months. The cereals were equally effective in providing relative protection from ID. The results of these three studies indicate it is possible to protect breastfed infants from ID and IDA.

Dry cereals fortified with electrolytic iron or ferrous fumarate are equally effective in breast-fed infants

Precooked, instant (dry) infant cereals in the US are fortified with electrolytic iron, a source of low reactivity and suspected low bioavailability. Iron from ferrous fumarate is presumed to be more available. In this study, we compared a dry infant rice cereal (Cereal L) fortified with electrolytic iron (54.5 mg iron/100 g cereal) to a similar cereal (Cereal M) fortified with ferrous fumarate (52.2 mg Fe/100 g) for efficacy in maintaining iron status and preventing iron deficiency (ID) in breast-fed infants. Ascorbic acid was included in both cereals. In this prospective, randomized double-blind trial, exclusively breast-fed infants were enrolled at 1 mo and iron status was determined periodically. At 4 mo, 3 infants had ID anemia and were excluded. Ninety-five infants were randomized at 4 mo, and 69 (36 Cereal L, 33 Cereal M) completed the intervention at 9 mo. From 4 to 9 mo, they consumed daily one of the study cereals. With each cereal, 2 infants had mild ID, a prevalence of 4.2%, but no infant developed ID anemia. There were no differences in iron status between study groups. Iron intake from the study cereals was (mean ± SD) 1.21 ± 0.31 mg⋅kg(-1)⋅d(-1) from Cereal L and 1.07 ± 0.40 mg⋅kg(-1)⋅d(-1) from Cereal M. Eleven infants had low birth iron endowment (plasma ferritin < 55 μg/L at 2 mo) and 54% of these infants had ID with or without anemia by 4 mo. We conclude that electrolytic iron and ferrous fumarate were equally efficacious as fortificants of this infant cereal.

Canadian infants' nutrient intakes from complementary foods during the first year of life

Background

Complementary feeding is currently recommended after six months of age, when the nutrients in breast milk alone are no longer adequate to support growth. Few studies have examined macro- and micro-nutrient intakes from complementary foods (CF) only. Our purpose was to assess the sources and nutritional contribution of CF over the first year of life.

Methods

In July 2003, a cross-sectional survey was conducted on a nationally representative sample of mothers with infants aged three to 12 months. The survey was administered evenly across all regions of the country and included a four-day dietary record to assess infants' CF intakes in household (tablespoon) measures (breast milk and formula intakes excluded). Records from 2,663 infants were analyzed for nutrient and CF food intake according to 12 categories. Mean daily intakes for infants at each month of age from CF were pooled and compared to the Dietary Reference Intakes for the respective age range.

Results

At three months of age, 83% of infants were already consuming infant cereals. Fruits and vegetables were among the most common foods consumed by infants at all ages, while meats were least common at all ages except 12 months. Macro- and micro-nutrient intakes from CF generally increased with age. All mean nutrient intakes, except vitamin D and iron, met CF recommendations at seven to 12 months.

Conclusions

Complementary foods were introduced earlier than recommended. Although mean nutrient intakes from CF at six to 12 months appear to be adequate among Canadian infants, further attention to iron and vitamin D intakes and sources may be warranted.

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.

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.