Serum iron analysis of adults receiving three different iron compounds

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.

Effects of over-load iron on nutrient digestibility, haemato-biochemistry, rumen fermentation and bacterial communities in sheep

There is a risk of iron overload in grazing livestock. However, the effects on nutrient absorption and rumen function induced by excessive iron have not been well understood. Therefore, the purpose of present study was to investigate the impact of over-load iron on growth performance, nutrient digestibility, blood biochemistry, rumen fermentation and bacterial communities in sheep. Twenty-four German Mutton Merino cross-bred sheep with weight (42.66 ± 2.34 kg BW) were randomly divided into 4 groups, each with 6 replicates and 1 sheep per replicate. The basal diet consisted of 60% Leymus chinensis hay and 40% concentrate. The sheep in 4 groups were fed the basal diets supplemented with 50 (Control), 500 (T1), 1,000 (T2) and 1,500 (T3) mg Fe/kg as ferrous sulphate monohydrate (FeSO₄ ·H₂ O) respectively. And the actual contents of iron in the diet were determined to be 457.68 (control), 816.42 (T1), 1,256.78 (T2) and 1,725.63 (T3) mg/kg respectively. The experiment lasted 62 days including a 7-day metabolism trial. During the whole experiment, the digestibility of dry matter, organic matter, neutral detergent fibre and acid detergent fibre showed a quadratic increase with increasing over-load iron levels (p < .05), and maximum responses were found with 500 mg/kg supplementation. However, the response of total VFA concentration showed a quadratic decrease, as did the concentrations of propionate, butyrate and valerate (p < .05). Serum total iron-binding capacity on day 30 showed a quadratic decrease with the increase in high-dose iron, while the serum iron content increased linearly at day 60 (p < .05). Excessive iron resulted in the change in bacterial communities. An increase in over-load iron linearly decreased the abundance of bacteria in the phylum Bacteroidetes (p < .05), but linearly increased the Firmicutes (p = .037) and Proteobacteria (p = .018). In addition, there was a quadratic effect (p = .003) on the Fibrobacteres, which was higher in the 500 and 1,000 mg/kg Fe-supplemented groups. At the genus level, there were quadratic effects on the abundances of Selenomonas_1 (p = .023) and Ruminococcaceae_UCG-014 (p = .016). Furthermore, feeding of iron linearly increased the relative abundances of Succiniclasticum and Succinivibrionaceae_UCG-002 (p < .05). These results indicate that increasing ferrous sulphate monohydrate in diets had no negative impact on the growth performance, but it changed nutrient digestibility, blood iron parameters, rumen fermentation and bacterial communities in sheep.

Effect of different sources and levels of iron in the diet of sows on iron status in neonatal pigs

This study was conducted to determine the effects of maternal dietary supplementation of ferrous glycine chelate (Fe-Gly) and ferrous sulfate monohydrate (FeSO₄·H₂O) on the relative organ weight, tissue iron contents, red blood cells (RBC), hemoglobin concentration (HGB) and hematocrit (HCT) in blood, as well as ferritin (Fn), serum iron (SI), and total iron binding capacity (TIBC) in serum of newborn piglets. Forty-five sows (Landrace × Large white, mean parity 3 to 4, no significant differences in BW) were randomly allotted to 9 treatments (n = 5 sows/treatment): control (basal diet with no Fe supplementation), the basal diet supplemented with 50, 80, 110 or 140 mg Fe/kg as Fe-Gly, and the basal diet supplemented with 50, 80, 110 or 140 mg Fe/kg as FeSO₄·H₂O. The neonatal piglets (n = 45) were used to determine the relative organ weight, tissue iron contents and blood biochemical indices. Compared with the control, the relative weight of spleen and kidney were significantly increased (P < 0.05) in the Fe-Gly groups. The iron contents in liver, spleen, kidney and femur were also found increased (P < 0.05) in the Fe-Gly groups. The RBC (d 1 and 21), HGB (d 1 and 21) and HCT (d 1 and 21) in blood and Fn (d 1) and SI (d 1 and 21) significantly increased (P < 0.05), but the TIBC (d 1 and 21) in serum decreased (P < 0.05) in the Fe-Gly groups. Moreover, the kidney relative weight, iron content in liver, spleen, kidney and femur, RBC (d 1) and HGB (d 21) in blood, and SI (d 1) in the Fe-Gly groups increased (P < 0.05) compared with the FeSO₄·H₂O treatment. Linear and quadratic responses of the kidney relative weight, the iron content in liver, spleen, kidney and femur, RBC (d 1 and 21), HGB (d 1 and 21) and HCT (d 1 and 21) in whole blood, SI (d 1) and TIBC (d 1 and 21) in the Fe-Gly groups were observed (P < 0.05). Linear responses of Fn (d 1 and 21) and SI (d 21) in the Fe-Gly groups, and spleen relative weight, HCT (d 1), Fn (d 1) and TIBC (d 1 and 21) in the FeSO₄·H₂O groups were observed (P < 0.05). These finding suggest that Fe-Gly supplemented at the level of 110 mg/kg in the diet of sows in this experiment is superior to other forms of supplementation, based on HGB concentration, the relative organ weight, tissue iron contents and blood biochemical indices of piglets.

Studies on different iron source absorption by in situ ligated intestinal loops of broilers

The objective of this study was to investigate the iron source absorption in the small intestine of broiler. In situ ligated intestinal loops of 70 birds were poured into one of seven solutions, including inorganic iron (FeSO4, Fe2(SO4)3), organic Fe glycine chelate (Fe-Gly(II), Fe-Gly(III)), the mixtures (FeSO4 with glycine (Fe+Gly(II)), Fe2(SO4)3 with glycine (Fe+Gly(III)), and no Fe source (control). The total volume of 3-mL solution (containing 1 mg of elemental Fe) was injected into intestinal loops, and then 120-min incubation was performed. Compared with inorganic iron groups, in which higher FeSO4 absorption than Fe2(SO4)3 was observed, supplementation with organic Fe glycine chelate significantly increased the Fe concentration in the duodenum and jejunum (P < 0.05), however, decreased DMT1 and DcytB messenger RNA (mRNA) levels (P < 0.05). Organic Fe glycine chelate (Fe-Gly(II), Fe-Gly(III)) increased serum iron concentration (SI), compared with inorganic 3 valence iron groups (Fe2(SO4)3 and Fe+Gly(III)) (P < 0.05); moreover, lower TIBC value was observed for the chelate (P < 0.05); however, mixture of inorganic iron and glycine did not have a positive role at DMT1 and DcytB mRNA levels, SI and Fe concentrations in the small intestine. Those results indicated that the absorption of organic Fe glycine chelate was more effective than that of inorganic Fe, and the orders of iron absorption in the small intestine were: Fe-Gly(II), Fe-Gly(III) > FeSO4, Fe+Gly(II) > Fe2(SO4)3, Fe+Gly(III). Additionally, the simple mixture of inorganic iron and glycine could not increase Fe absorption, and the duodenum was the main site of Fe absorption in the intestines of broilers and the ileum absorbed iron rarely.

Effect of iron supplementation on the expression of hypoxia-inducible factor and antioxidant status in rats exposed to high-altitude hypoxia environment

Iron and oxygen are essential substance for cellular activity in body tissues. Hypoxia-inducible factors (HIFs) can respond to available oxygen changes in the cellular environment and regulate the transcription of a series of target genes. The study was conducted to investigate the effects of iron supplementation on the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and antioxidant status in rats exposed to high-altitude hypoxia environment. Forty rats were divided into control (CON), hypobaric hypoxia (HH), and hypobaric hypoxia plus ferrous sulfate (FeSO4) (9.93 mg/kg body weight (BW)/day) (HFS) and hypobaric hypoxia plus iron glycinate chelate (Fe-Gly) (11.76 mg/kg BW/day) (HFG) groups. Results showed that Fe-Gly effectively alleviated weight loss and intestinal mucosa damage induced by hypobaric hypoxia, whereas FeSO4 aggravated hypobaric hypoxia-induced weight loss, liver enlargement, spleen atrophy, and intestinal damage. Iron supplementation decreased liver superoxide dismutase (T-SOD) and catalase (CAT) activity (P < 0.01) and increased iron concentration in the liver compared to HH group (P < 0.001). Moreover, Fe-Gly upregulated liver transferrin expression in messenger RNA (mRNA) level (P < 0.05) and downregulated serum erythropoietin (EPO) concentration (P < 0.01) and liver HIF-1α expression level (P < 0.05 in mRNA level; P < 0.001 in protein level) compared to HH group. The study indicated that FeSO4 supplementation at high altitudes aggravated the oxidative damage of tissues and organs that could be mediated through production of malondialdehyde (MDA) and inhibition antioxidant enzyme activities. Fe-Gly can protect hypobaric hypoxia-induced tissues injury. Moreover, iron supplementation at high altitudes affected HIF-1α-mediated regulating expression of targeting genes such as EPO and transferrin. The study highlights that iron supplementation under hypobaric hypoxia environment has possible limitation, and efficient supplementation form and dosage need careful consideration.

A question mark on iron deficiency in 185 million people of Pakistan: its outcomes and prevention

Micronutrient deficiency especially the iron deficiency is the bane of our lives, affecting all strata of society. Unfortunately, the women during pregnancy, adolescence, and children are under this curse particularly in developing countries like Pakistan. It is one of the biggest reasons of complications during pregnancy and malnourished children under five years of age. Maternal death, still-births, and underweight births are most common consequences of iron deficiency and these outbreaks as iron-deficiency anemia in Pakistan. Disastrous nature of iron deficiency requires an urgent call to eradicate it. Hence, the solution should not be frail comparing with the huge economic loss and other incompatibilities. Flour fortification, supplementation, dietary diversification, and especially maternal education are possible solutions for combating this micronutrient deficiency.

Fortification iron as ferrous sulfate plus ascorbic acid is more rapidly absorbed than as sodium iron EDTA but neither increases serum nontransferrin-bound iron in women

The absorption profile of iron fortificants may be a determinant of their ability to generate nontransferrin-bound iron (NTBI) and, thus, their potential safety. Ferrous iron may be absorbed more rapidly than chelated ferric iron, but differences at the fortification level cannot be distinguished with nonisotopically labeled serum iron curves. Using stable isotope appearance curves (SIAC) in serum, we measured iron absorption profiles from FeSO(4) with ascorbic acid (AA) and from NaFeEDTA, as well as the serum hepcidin and NTBI response following the meals. Healthy women (n = 16) were given 6 mg oral iron as labeled FeSO(4) and NaFeEDTA with a maize porridge using a crossover design. SIAC, NTBI, and serum hepcidin were measured over 8 h after the meal. Iron from FeSO(4) plus AA was more rapidly absorbed, resulting in a 35% greater relative AUC during the first 2 h than for NaFeEDTA (P < 0.001). Median (95% CI) fractional iron absorption from the FeSO(4)- and NaFeEDTA-fortified meals was 15.2% (11.0-19.5) and 6.0% (5.0-9.2), respectively (P < 0.001). In response to the FeSO(4)-fortified meal, there was an ~60% increase in median serum hepcidin (P < 0.05) but no significant change in NTBI. There was no significant change in serum hepcidin or NTBI after the NaFeEDTA-fortified meal. SIAC are a useful new tool to compare iron absorption profiles from different iron compounds in fortified foods. Even with the use of a very well absorbed ferrous iron compound, iron fortification in this population does not increase NTBI, suggesting a low risk for adverse health consequences.