Iron absorption from ferrous fumarate in adult women is influenced by ascorbic acid but not by Na2EDTA

Iron absorption in adults with sickle cell anemia: a stable-isotope approach

PURPOSE

Iron absorption in sickle cell anemia (SCA) remains unclear and studies in adults with SCA are scarce. The aim of this study was to evaluate the iron absorption SCA adults and its association with iron status and hepcidin concentration.

METHODS

SCA patients (n = 13; SCAtotal) and control participants (n = 10) ingested an oral stable iron isotope (57Fe). Iron absorption was measured by inductively coupled plasma mass spectrometry (ICP-MS) 14 days after isotope administration. Patients with ≥ 1000 ng/mL serum ferritin were considered to present iron overload (IO) (SCAio+; n = 3) and others classified without IO (SCAio-; n = 10).

RESULTS

Iron absorption in the control group ranged from 0.3 to 26.5% (median = 0.9%), while it varied from 0.3 to 5.4% in SCAio+ (median = 0.5%) and from 0.3 to 64.2% in the SCAio- (median = 6.9%). Hepcidin median values were 14.1 ng/mL (3.0-31.9 ng/mL) in SCAio-, 6.2 ng/mL (3.3-7.8 ng/mL) in SCAio + and 6.2 ng/mL (0.6-9.3 ng/mL) in control. Iron absorption was associated with ferritin level (r = - 0.641; p = 0.018) and liver iron concentration (LIC; r = - 0.786; p = 0.036) in the SCAtotal group.

CONCLUSION

Our data suggest that SCAio- individuals may be at risk of developing primary IO. Simultaneously, secondary IO may induce physiological adaptation, resulting in reduced iron absorption. Further studies evaluating intestinal iron absorption using larger sample sizes should be conducted to help establish a safe nutrition approach to be adopted and to ensure the security of food-fortifying public policies for these patients.

TRIAL REGISTRATION

This trial was registered at www.ensaiosclinicos.gov.br (Identifier RBR-4b7v8pt).

Nutritional Assessment of Adult Patients Undergoing Maintenance Hemodialysis in the Gaza Strip

Malnutrition is a common condition in patients undergoing hemodialysis (HD), and it is associated with increased morbidity and mortality. The main objective of the study was to evaluate the nutritional status of patients on maintenance HD. After applying eligibility criteria, 141 HD patients attending major governmental dialysis centers were randomly recruited in this cross-sectional study and assessed for nutritional status using the Patient-Generated Subjective Global Assessment (PG-SGA) tool. The PG-SGA categorizes patients as well-nourished, moderately malnourished, and severely malnourished. Different anthropometric measurements, laboratory investigations, blood pressure measurements, and 24-h dietary recall were collected from each patient. According to PG- SGA results, 78% of patients were moderately malnourished and 22% of patients were severely malnourished. The mean body mass index was 27.8 kg/m2, and 5.7% of patients were underweight. There were significant differences in the mid-upper arm muscle circumference (P = 0.020) between the PG-SGA groups. The total energy and protein intake were significantly (P <0.001) less than the recommended dietary intake by 1268.9 kcal and 41.4 g, respectively. The albumin level in 37.6% of patients was less than the normal level, and the results indicated that there were significant differences in serum iron (P = 0.022) between the moderately and severely malnourished patients. The results of this study indicated that all HD patients were suffering from different degrees of malnutrition and, unfortunately, most of their energy and nutrient intake was far less than the requirements, which might be the reason why they face nutritional and health risks.

Can the supplementary consumption of baobab (Adansonia digitata L.) fruit pulp improve the hemoglobin levels and iron status of schoolchildren in Kenya? Findings of a randomized controlled intervention trial

PURPOSE

In the rural Kenyan diet, the bioavailability of iron is low and predisposes the population to iron deficiency. Fruit pulp of the indigenous baobab tree contains significant amounts of vitamin C, which enhances non-heme iron bioavailability. We studied the impact of baobab fruit pulp (BFP) consumption on the hemoglobin (Hb) and iron status of Kenyan schoolchildren.

METHODS

The single-blind randomized controlled intervention trial was implemented daily among apparently healthy schoolchildren aged 6-12 years with hemoglobin level < 12.2 g/dl. For 12 weeks, children in the intervention group (n = 29) received a drink with BFP, while the control group (n = 29) received an isoenergy drink without BFP. At baseline and endline, blood samples were taken.

RESULTS

The development of hemoglobin, ferritin (FER) and soluble transferrin receptor (sTfR) did not differ significantly between the intervention and control groups. However, in the intervention group, Hb levels improved slightly (2.2%), while they decreased slightly (1.2%) in the control group. Levels of geometric means of sTfR remained almost unchanged (0.7%) in the intervention group and slightly worsened (2.7%) in the control group. In both the groups, geometric mean of FER levels decreased, yet to a smaller extent in the intervention (17.3%) than in the control (26.0%) group.

CONCLUSION

Even though no significant effects of BFP could be detected in this study, the identification of products such as BFP remains pertinent to help improve non-heme iron absorption in the most vulnerable populations.

Vitamin C deficiency and impact of vitamin C administration among pediatric patients with advanced chronic kidney disease

BACKGROUND

Vitamin C deficiency is common in chronic kidney disease (CKD) due to losses through dialysis and dietary intake below requirement. We investigated prevalence of vitamin C deficiency and impact of vitamin C treatment in deficient/insufficient patients.

METHODS

A prospective cohort study in patients aged 1-18 years with CKD stages 4 and 5D collected demographic data including underlying disease, treatment, and anthropometric assessment. Vitamin C intake was assessed using 24-h dietary recall. Hemoglobin, iron status, serum vitamin C, and serum oxalate were measured at baseline and after treatment. Vitamin C (250 mg/day) was given orally for 3 months to deficient/insufficient patients.

RESULTS

Nineteen patients (mean age 12.00 ± 4.1 years) showed prevalence of 10.6% vitamin C insufficiency and 78.9% deficiency. There were no associations between vitamin C level and daily vitamin C intake (p = 0.64) or nutritional status (p = 0.87). Median serum vitamin C was 1.51 (0.30-1.90) mg/L. In 16 patients receiving treatment, median serum vitamin C increased from 1.30 (0.23-1.78) to 3.22 (1.77-5.96) mg/L (p = 0.008) without increasing serum oxalate (79.92 (56.6-106.84) vs. 80.47 (56.88-102.95) μmol/L, p = 0.82). However, 62.5% failed to achieve normal vitamin C levels. Ordinal regression analysis revealed patients with non-oligoanuric CKD were less likely to achieve normal vitamin C levels (β = - 3.41, p = 0.03).

CONCLUSION

We describe high prevalence of vitamin C insufficiency/deficiency among pediatric CKD patients. Vitamin C levels could not be solely predicted by nutritional status or daily intake. The treatment regimen raised serum vitamin C without increasing serum oxalate; however, it was largely insufficient to normalize levels, particularly in non-oligoanuric CKD. Graphical abstract .

Vitamin C overload may contribute to systemic oxalosis in children receiving dialysis

BACKGROUND

Malnutrition and anorexia are common in children with chronic kidney disease (CKD) and gastrostomy tubes (GT) as well as nasogastric tubes (NGT) have been recommended to maximize nutritional support. The optimal requirement of vitamin C in children with CKD remains to be defined but oxalate is a breakdown product of vitamin C. Elevated vitamin C intake and bone oxalate were identified in two formula-fed dialyzed children with negative genetic testing for primary hyperoxaluria.

METHODS

We evaluated the impact of nutritional support on serum ascorbic acid and plasma oxalate levels in 13 dialyzed infants and young children.

RESULTS

All patients were fed by GT or NGT since the first months of life; overall patients were receiving between 145 and 847% of the age-specific DRI for vitamin C. Mean serum ascorbic acid and plasma oxalate levels were elevated (244.7 ± 139.7 μM/L and 44.3 ± 23.1 μM/L, respectively), and values did not differ according to the degree of residual kidney function. Ascorbic acid levels did not correlate with oxalate levels (r = 0.44, p = 0.13).

CONCLUSIONS

Excessive vitamin C intake may contribute to oxalate accumulation in dialyzed children.

Refining Treatment Strategies for Iron Deficient Athletes

Iron deficiency (ID) is a prevailing nutritional concern amongst the athletic population due to the increased iron demands of this group. Athletes' ability to replenish taxed iron stores is challenging due to the low bioavailability of dietary sources, and the interaction between exercise and hepcidin, the primary iron-regulatory hormone. To date, copious research has explored the link between exercise and iron regulation, with a more recent focus on optimising iron treatment applications. Currently, oral iron supplementation is typically the first avenue of iron replacement therapy beyond nutritional intervention, for treatment of ID athletes. However, many athletes encounter associated gastrointestinal side-effects which can deter them from fulfilling a full-term oral iron treatment plan, generally resulting in sub-optimal treatment efficacy. Consequently, various strategies (e.g. dosage, composition, timing) of oral iron supplementation have been investigated with the goal of increasing fractional iron absorption, reducing gastric irritation, and ultimately improving the efficacy of oral iron therapy. This review explores the various treatment strategies pertinent to athletes and concludes a contemporary strategy of oral iron therapy entailing morning supplementation, ideally within the 30 min following morning exercise, and in athletes experiencing gut sensitivity, consumed on alternate days or at lower doses.

Acute Consumption of Prebiotic Galacto-Oligosaccharides Increases Iron Absorption from Ferrous Fumarate, but not from Ferrous Sulfate and Ferric Pyrophosphate: Stable Iron Isotope Studies in Iron-Depleted Young Women

BACKGROUND

Although acute consumption of high doses of prebiotic galacto-oligosaccharides (GOS) increases fractional iron absorption (FIA) from ferrous fumarate (FeFum), it is uncertain if low doses of GOS have this effect. Furthermore, whether GOS improve iron absorption from other commonly used iron compounds and whether ascorbic acid (AA) enhances the effect of GOS on iron absorption from FeFum is unclear.

OBJECTIVES

In iron-depleted women [serum ferritin (SF) <30 μg/L], we assessed: 1) whether the acute enhancing effect of GOS on FeFum is dose dependent; 2) if GOS would affect FIA from ferrous sulfate (FeSO4) or ferric pyrophosphate (FePP); and 3) if AA and GOS given together enhance FIA from FeFum to a greater extent compared with GOS alone.

METHODS

We recruited 46 women (mean age 22.0 y, mean BMI 21.3 kg/m2, median SF 17.1 μg/L), and measured FIA from 14 mg iron labeled with stable isotopes in the following conditions: 1) FIA from FeFum given with 3.5 g, 7 g GOS, and without GOS; 2) FIA from FeSO4 and FePP given with and without 15 g GOS; and 3) FIA from FeFum given with 7 g GOS with and without 93 mg AA. FIA was measured as erythrocyte incorporation of stable isotopes after 14 d. Comparisons were made using paired samples t-test or Wilcoxon rank sum test where appropriate.

RESULTS

Giving 7 g of GOS significantly increased FIA from FeFum (+26%; P = 0.039), whereas 3.5 g GOS did not (P = 0.130). GOS did not significantly increase FIA from FeSO4 (P = 0.998) or FePP (P = 0.059). FIA from FeFum given with GOS and AA was significantly higher compared with FeFum given with GOS alone (+30%; P <0.001).

CONCLUSIONS

In iron-depleted women, GOS does not increase FIA from FeSO4 or FePP, but it increases FIA from FeFum. Thus, a combination of FeFum and GOS may be a well-absorbed formula for iron supplements. The study was registered at clinicaltrials.gov as NCT03762148.

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

BACKGROUND

A highly soluble iron-casein complex has been developed for food fortification purposes with the aim to provide high iron bioavailability.

OBJECTIVE

We aimed to determine the iron bioavailability of the iron-casein complex relative to that of ferrous sulfate (control) when given with whole milk in healthy young women.

METHODS

A randomized comparator-controlled trial with a crossover design was conducted using the erythrocyte incorporation dual stable isotope (57Fe, 58Fe) technique. Iron absorption from the iron-casein complex was compared with that from ferrous sulfate in 21 healthy women aged 20-38 y with normal iron status.

RESULTS

Fractional iron absorption (geometric mean; -SD, +SD) from the iron-casein complex (3.4%; 1.4%, 5.4%) and from ferrous sulfate (3.9%; 1.7%, 6.1%) were not statistically different (P > 0.05). The relative bioavailability value of the iron-casein complex to ferrous sulfate was determined to be 0.87 (-1 SD, +1 SD: -0.90, +2.64).

CONCLUSIONS

The iron-casein complex has iron bioavailability comparable to that of ferrous sulfate in healthy young women. This trial was registered at www.anzctr.org.au as ACTRN12615000690550.

Consumption of Galacto-Oligosaccharides Increases Iron Absorption from Ferrous Fumarate: A Stable Iron Isotope Study in Iron-Depleted Young Women

BACKGROUND

Animal studies suggest prebiotics can increase iron absorption, but results from human studies are equivocal.

OBJECTIVES

In iron-depleted women, before (baseline) and after daily consumption of galacto-oligosaccharides (GOS) for 4 wk, we sought to assess fractional iron absorption (FIA) from an iron supplement given with and without single doses of GOS in test meals or water.

METHODS

In all women (n = 34; median serum ferritin concentration = 16.4 µg/L), FIA from doses of 14 mg iron labeled with stable isotopes was measured in the following conditions at baseline: 1) FIA from ferrous fumarate (FeFum) in water given with and without 15 g GOS; 2) FIA from FeFum in a test meal given with and without 15 g GOS; 3) FIA from ferrous sulfate (FeSO4) in a test meal given without 15 g GOS. All subjects then consumed ∼15 g GOS daily for 4 wk. Then the following conditions were tested: 4) FIA from FeFum in a test meal with and without 15 g GOS; and 5) FIA from FeSO4 in a test meal with 15 g GOS. FIA was measured as erythrocyte incorporation of stable isotopes.

RESULTS

At baseline, GOS significantly increased FIA from FeFum when given with water (+61%; P < 0.001) and the meal (+28%; P = 0.002). After 4 wk of GOS consumption, GOS again significantly increased FIA from FeFum in the meal (+29%; P = 0.044). However, compared with baseline, consumption of GOS for 4 wk did not significantly enhance absorption from FeFum in the meal given without GOS. FIA from FeSO4 given with GOS in a meal after 4 wk of GOS consumption was not significantly greater than FIA from FeSO4 in a meal without GOS at baseline.

CONCLUSIONS

In iron-depleted women, GOS given with FeFum increases FIA, but 4 wk of GOS consumption did not enhance this effect. The study was registered at clinicaltrials.gov as NCT03325270.

Vitamin and trace element deficiencies in the pediatric dialysis patient

Pediatric dialysis patients are at risk of nutritional illness secondary to deficiencies in water-soluble vitamins and trace elements. Unlike 25-OH vitamin D, most other vitamins and trace elements are not routinely monitored in the blood and, consequently, the detection of any deficiency may not occur until significant complications develop. Causes of vitamin and trace element deficiency in patients on maintenance dialysis patient are multifactorial, ranging from diminished nutritional intake to altered metabolism as well as dialysate-driven losses of water-soluble vitamins and select trace elements. In this review we summarize the nutritional sources of key water-soluble vitamins and trace elements with a focus on the biological roles and clinical manifestations of their respective deficiency to augment awareness of potential nutritional illness in pediatric patients receiving maintenance dialysis. The limited pediatric data on the topic of clearance of water-soluble vitamins and trace elements by individual dialysis modality are reviewed, including a brief discussion on clearance of water-soluble vitamins and trace elements with continuous renal replacement therapy.

Consumption of galacto-oligosaccharides increases iron absorption from a micronutrient powder containing ferrous fumarate and sodium iron EDTA: a stable-isotope study in Kenyan infants

Background: Whether consumption of prebiotics increases iron absorption in infants is unclear.Objective: We set out to determine whether prebiotic consumption affects iron absorption from a micronutrient powder (MNP) containing a mixture of ferrous fumarate and sodium iron EDTA (FeFum+NaFeEDTA) in Kenyan infants.Design: Infants (n = 50; aged 6-14 mo) consumed maize porridge that was fortified with an MNP containing FeFum+NaFeEDTA and 7.5 g galacto-oligosaccharides (GOSs) (Fe+GOS group, n = 22) or the same MNP without GOSs (Fe group, n = 28) each day for 3 wk. Then, on 2 consecutive days, we fed all infants isotopically labeled maize porridge and MNP test meals containing 5 mg Fe as ⁵⁷FeFum+Na⁵⁸FeEDTA or ferrous sulfate (⁵⁴FeSO₄). Iron absorption was measured as the erythrocyte incorporation of stable isotopes. Iron markers, fecal pH, and bacterial groups were assessed at baseline and 3 wk. Comparisons within and between groups were done with the use of mixed-effects models.Results: There was a significant group-by-compound interaction on iron absorption (P = 0.011). The median percentages of fractional iron absorption from FeFum+NaFeEDTA and from FeSO₄ in the Fe group were 11.6% (IQR: 6.9-19.9%) and 20.3% (IQR: 14.2-25.7%), respectively, (P < 0.001) and, in the Fe+GOS group, were 18.8% (IQR: 8.3-37.5%) and 25.5% (IQR: 15.1-37.8%), respectively (P = 0.124). Between groups, iron absorption was greater from the FeFum+NaFeEDTA (P = 0.047) in the Fe+GOS group but not from the FeSO₄ (P = 0.653). The relative iron bioavailability from FeFum+NaFeEDTA compared with FeSO₄ was higher in the Fe+GOS group than in the Fe group (88% compared with 63%; P = 0.006). There was a significant time-by-group interaction on Bifidobacterium spp. (P = 0.008) and Lactobacillus/Pediococcus/Leuconostoc spp. (P = 0.018); Lactobacillus/Pediococcus/Leuconostoc spp. decreased in the Fe group (P = 0.013), and there was a nonsignificant trend toward higher Bifidobacterium spp. in the Fe+GOS group (P = 0.099). At 3 wk, iron absorption was negatively correlated with fecal pH (P < 0.001) and positively correlated with Lactobacillus/Pediococcus/Leuconostoc spp. (P = 0.001).Conclusion: GOS consumption by infants increased iron absorption by 62% from an MNP containing FeFum+NaFeEDTA, thereby possibly reflecting greater colonic iron absorption. This trial was registered at clinicaltrials.gov as NCT02666417.

In Haitian women and preschool children, iron absorption from wheat flour-based meals fortified with sodium iron EDTA is higher than that from meals fortified with ferrous fumarate, and is not affected by Helicobacter pylori infection in children

Fe fortification of wheat flour was proposed in Haiti to combat Fe deficiency, but Fe bioavailability from fortificants has never been investigated in Haitian women or preschool children, two key target groups. We aimed to investigate the bioavailability of ferrous fumarate (FeFum), NaFeEDTA and their combination from fortified wheat flour. We recruited twenty-two healthy mother-child pairs in Port au Prince, Haiti, for an Fe-absorption study. We administered stable Fe isotopes as FeFum or NaFeEDTA individually in low-extraction wheat flour bread rolls consumed by all participants in a randomised, cross-over design. In a final, identical meal, consumed only by the women, FeFum+NaFeEDTA was administered. We measured Fe absorption by using erythrocyte incorporation of stable isotopes 14 d after consumption of each meal, and determined Fe status, inflammatory markers and Helicobacter pylori infection. Fe absorption (geometric mean was 9·24 (95 % CI 6·35, 13·44) and 9·26 (95 % CI 7·00, 12·31) from FeFum and 13·06 (95 % CI 9·23, 19·10) and 12·99 (95 % CI 9·18, 18·39) from NaFeEDTA in mothers and children, respectively (P<0·05 between compounds). Fe absorption from FeFum+NaFeEDTA was 11·09 (95 % CI 7·45, 17·34) and did not differ from the other two meals. H. pylori infection did not influence Fe absorption in children. In conclusion, in Haitian women and children, Fe absorption from NaFeEDTA was 40 % higher than from FeFum, and the combination FeFum+NaFeEDTA did not significantly increase Fe absorption compared with FeFum alone. In the context of Haiti, where the high costs of NaFeEDTA may not be affordable, the use of FeFum at 60 mg Fe/kg flour may be a preferable, cost-effective fortification strategy.

Influence of phytase, EDTA, and polyphenols on zinc absorption in adults from porridges fortified with zinc sulfate or zinc oxide

Fortification of cereal staples with zinc is recommended to combat zinc deficiency. To optimize zinc absorption, strategies are needed to overcome the inhibitory effect of phytic acid (PA) and perhaps polyphenols. Five zinc absorption studies were conducted in young adults consuming maize or sorghum porridges fortified with 2 mg zinc as zinc sulfate (ZnSO4) or zinc oxide (ZnO) and containing combinations of PA or polyphenols as potential inhibitors and EDTA and phytase as potential enhancers. Fractional absorption of zinc (FAZ) was measured by using the double isotopic tracer ratio method. Adding phytase to the maize porridge immediately before consumption or using phytase for dephytinization during meal preparation both increased FAZ by >80% (both P < 0.001). Adding Na2EDTA at an EDTA:zinc molar ratio of 1:1 increased FAZ from maize porridge fortified with ZnSO4 by 30% (P = 0.01) but had no influence at higher EDTA ratios or on absorption from ZnO. FAZ was slightly higher from ZnSO4 than from ZnO (P = 0.02). Sorghum polyphenols had no effect on FAZ from dephytinized sorghum porridges but decreased FAZ by 20% from PA-rich sorghum porridges (P < 0.02). The combined inhibitory effect of polyphenols and PA was overcome by EDTA. In conclusion, ZnSO4 was better absorbed than ZnO, phytase used to degrade PA during digestion or during food preparation substantially increased zinc absorption from zinc-fortified cereals, EDTA at a 1:1 molar ratio modestly enhanced zinc absorption from ZnSO4-fortified cereals but not ZnO-fortified cereals, and sorghum polyphenols inhibited zinc absorption in the presence, but not absence, of PA. This trial was registered at clinicaltrials.gov as NCT01210794.

Consumption habits and innovation potential of mung bean foods in Hisar District of Haryana State, India

Consumption habits for mung bean foods were assessed by the free word association method and interview techniques. Four groups of closely related products and perceived quality were revealed. The largest group comprised sweets and snacks, which were associated with unhealthiness, expensiveness and sensory liking. Another group consisted of split dhals associated with convenience and healthiness. It appeared that under different circumstances food choices vary and are influenced more by socioeconomic restrictions then by consumer perception and preferences. Scenario analysis based on consumer perception, preferences, practices and nutritional value of products revealed dhals as the most promising food for innovation.

Is vitamin C intake too low in dialysis patients?

Vitamin C has several well-established roles in physiology including synthesis of collagen, carnitine and epinephrine, absorption of dietary iron, and mobilization of storage iron for erythropoeisis. Loss of several of these functions explains the pathology of scurvy, where defective collagen synthesis and anemia are major symptoms. Vitamin C deficiency is very common in dialysis patients and may arise from dialytic vitamin C clearance, restricted intake of vitamin C-rich foods, and increased vitamin C catabolism in vivo from inflammation. In the dialysis population, greater vitamin C intake may be needed for optimal health. Relationships between intake, body distribution, inflammation, and dialytic losses are complex and need further study. Concern about vitamin C metabolism leading to accumulation of tissue oxalate has led to the recommendation that vitamin C intake equals, but not exceeds, the intake recommended for the general population. Vitamin C deficiency in dialysis patients may have clinical consequences; a study in Renal Research Institute clinics found an association with periodontal disease. Data also support a role for vitamin C in prevention of dialysis-related anemia. New research questions are proposed in this editorial, with a discussion of strategies to determine the optimal provision of vitamin C for CKD patients.

Effect of Helicobacter pylori infection on iron absorption in asymptomatic adults consuming wheat flour fortified with iron and zinc

Helicobacter pylori infection could impair iron absorption from fortified products. The objective of the study was to determine the effect of H. pylori infection on iron absorption from asymptomatic adults consuming wheat flour fortified with iron and zinc. The (13)C urea breath test was used to assess H. pylori infection. Twenty-four H. pylori-positive and 26 H. pylori-negative volunteers completed the study. On day 1, the subjects were randomized to receive for breakfast bread fortified with either ferrous sulfate and zinc sulfate or ferrous fumarate and zinc oxide. Bread fortified with ferrous sulfate was labeled with (59)Fe as sulfate, and bread fortified with ferrous fumarate was labeled with (55)Fe as fumarate. On day 3, they received the other type of bread, with the respective tracers. On days 18-23, a proton pump inhibitor was administered to all subjects. On day 24, all subjects received bread fortified with ferrous fumarate and zinc oxide labeled with (55)Fe as fumarate. H. pylori prevalence was 77.6%. The geometric mean (±1 SD) of iron absorption was significantly higher for ferrous sulfate than fumarate (6.9 ± 2.9% vs. 0.5 ± 3.5%, p < 0.001). The H. pylori-negative subjects absorbed significantly more iron from bread fortified with either ferrous sulfate (10.5 ± 3.1% vs. 4.4 ± 2.2%, p < 0.001) or ferrous fumarate (0.6 ± 3.9% vs. 0.4 ± 3.1%, p < 0.001). Iron absorption was not significantly different between groups after administration of a proton pump inhibitor (0.3 ± 3.3% vs. 0.3 ± 2.7%, p = 0.11). H. pylori infection has a negative effect on iron absorption in asymptomatic adults consuming iron- and zinc-fortified wheat flour.

Bioavailability of micronutrients: stable isotope techniques to develop effective food-based strategies to combat micronutrient deficiencies

BACKGROUND

The prevalence of micronutrient deficiencies, in particular those of iron, vitamin A, iodine, and zinc, is unacceptably high, especially among infants, children, and women of childbearing age in developing countries. Effective food-based strategies to combat these public health problems are therefore urgently needed.

OBJECTIVE

As only a fraction of dietary iron, zinc, and provitamin A carotenoids is absorbed and utilized, i.e., bioavailable, access to information on micronutrient bioavailability is crucial in the development of food fortification strategies and interventions based on dietary diversification.

METHODS

Review of literature.

RESULTS AND CONCLUSIONS

This overview highlights the usefulness of stable isotope techniques to assess the bioavailability of nonheme iron and provitamin A carotenoids and the importance of generating data on micronutrient bioavailability to move the agenda forward.

Randomised comparison of the effects of Sprinkles and Foodlets with the currently recommended supplement (Drops) on micronutrient status and growth in Iranian children

BACKGROUND/OBJECTIVES

Multiple micronutrient supplementation with Sprinkles powder and crushable Foodlets tablets may be effective means of controlling micronutrient deficiencies in infants. Their efficacy has not been tested in countries like Iran where wheat as the staple food may affect nutrient bioavailability. This study aimed to compare the efficacy of Sprinkles, Foodlets and the current supplement (Drops) for improving micronutrient status and growth among Iranian infants.

SUBJECTS/METHODS

Infants of 6-18 months of age, living in an urban district of Iran were randomised to receive daily Sprinkles (n=120), Foodlets (n=121) or Drops (n=121) for 4 months. Haemoglobin (Hb), serum ferritin, serum retinol, serum zinc, 25(OH) D concentration and anthropometry were assessed at baseline and at 4 months.

RESULTS

Iron status improved with all treatments. Drops showed significantly greater changes in Hb and serum ferritin, though changes in anaemia prevalence were not different across groups. Infants having Foodlets and Sprinkles had significantly greater reductions in proportion of children with zinc deficiency compared with Drops. No significant differences in treatment effects were observed for mean serum 25(OH) D and retinol, or for growth of infants across groups.

CONCLUSION

The study was the first efficacy trial with Sprinkles and Foodlets in the Middle East where wheat or rice is the principal complementary foods. Differences across treatment groups were largely consistent with supplement micronutrient composition for iron and zinc, with no benefit in this population for serum retinol, 25(OH) D, growth or anthropometric status. The trial identified trade-offs in combining multiple micronutrients in a single delivery mechanism.

In situ chemichromic studies of interactions between a lutetium bis-octaalkyl-substituted phthalocyanine and selected biological cofactors

Spin-coated films, approximately 100 nm thick, of a newly synthesized bis[octakis(octyl)phthalocyaninato] lutetium(III) complex on ultrasonically cleaned glass substrates exhibit pronounced chemichromic behaviour with potential application in healthcare. In situ kinetic optical absorption spectroscopic measurements show that the phthalocyanine Q-band is red shifted by 60 nm upon oxidation arising from exposure to bromine vapour. Recovery to the original state is achieved by the treatment of the oxidized films with nicotinamide adenine dinucleotide and l-ascorbic acid (vitamin C) in an aqueous solution containing 1.5 M lithium perchlorate. The neutralization process is found to be governed by first-order kinetics. The linear increase of the reduction rate with increasing concentration of cofactors provides a basis for calibration of analyte concentrations ranging from 3.5 mM down to 0.03 mM.

A comparison of the bioavailability of ferrous fumarate and ferrous sulfate in non-anemic Mexican women and children consuming a sweetened maize and milk drink

BACKGROUND/OBJECTIVES

Ferrous fumarate is recommended for the fortification of complementary foods based on similar iron absorption to ferrous sulfate in adults. Two recent studies in young children have reported that it is only 30% as well absorbed as ferrous sulfate. The objective of this study was to compare iron absorption from ferrous fumarate and ferrous sulfate in infants, young children and mothers.

SUBJECTS/METHODS

Non-anemic Mexican infants (6-24 months), young children (2-5 years) and adult women were randomly assigned to receive either 4 mg Fe (women) or 2.5 mg Fe (infants and young children) as either [(57)Fe]-ferrous fumarate or [(58)Fe]-ferrous sulfate added to a sweetened drink based on degermed maize flour and milk powder. Iron absorption was calculated based on incorporation of isotopes into erythrocytes after 14 days.

RESULTS

Within each population group, no significant differences (P > 0.05) in iron absorption were found between ferrous fumarate and ferrous sulfate. Mean iron absorption from ferrous fumarate vs ferrous sulfate was 17.5 vs 20.5% in women (relative bioavailability (RBV) =86), 7.0 vs 7.2% in infants (RBV = 97) and 6.3 vs 5.9% in young children (RBV = 106).

CONCLUSIONS

Ferrous fumarate is as well absorbed as ferrous sulfate in non-anemic, iron sufficient infants and young children, and can be recommended as a useful fortification compound for complementary foods designed to prevent iron deficiency. Further studies are needed to clarify its usefulness in foods designed to treat iron deficiency.

Hemoglobin and plasma vitamin C levels in patients on peritoneal dialysis

OBJECTIVE

To determine the contribution of vitamin C (Vit C) status in relation to hemoglobin (Hb) levels in patients on long-term peritoneal dialysis (PD).

METHODS

56 stable PD patients were evaluated in a cross-sectional survey. Plasma samples were collected for Vit C (analyzed by HPLC with electrochemical detection) and high-sensitivity C-reactive protein (hs-CRP) determinations. Clinical records were reviewed for Hb, transferrin saturation (TSAT), ferritin, erythropoietin (EPO) dose, and other clinical parameters. Dietary Vit C intake was evaluated by patient survey and from patient records. Total Vit C removed during PD treatment was measured in 24-hour dialysate collections.

RESULTS

Patients showed a highly skewed distribution of plasma Vit C levels, with 40% of patients below normal plasma Vit C levels (<30 μmol/L) and 9% at higher than normal levels (>80 μmol/L). Higher plasma Vit C levels were associated with higher Hb levels (Pearson r = 0.33, p < 0.004). No direct connection between Vit C levels and reported dietary intake could be established. In stepwise multiple regression, plasma Vit C remained significantly associated with Hb (p = 0.017) but there was no significant association with other variables (dialysis vintage, age, ferritin, TSAT, hs-CRP, residual renal function, and EPO dose). In 9 patients that were evaluated for Vit C in dialysate, plasma Vit C was positively associated (Spearman r = 0.85, p = 0.01) with the amount of Vit C removed during dialysis treatment.

CONCLUSIONS

These data indicate that plasma Vit C is positively associated with higher Hb level. Vit C status could play a major role in helping PD patients to utilize iron for erythropoiesis and achieve a better Hb response during anemia management.

Orange but not apple juice enhances ferrous fumarate absorption in small children

OBJECTIVE

Ferrous fumarate is a common, inexpensive iron form increasingly used instead of ferrous sulfate as a food iron supplement. However, few data exist as to whether juices enhance iron absorption from ferrous fumarate.

SUBJECTS AND METHODS

We studied 21 children, ages 4.0 to 7.9 years using a randomized crossover design. Subjects consumed a small meal including a muffin containing 4 mg Fe as ferrous fumarate and either apple (no ascorbic acid) or orange juice (25 mg ascorbic acid). They were separately given a reference dose of Fe (ferrous sulfate) with ascorbic acid.

RESULTS

Iron absorption increased from 5.5% +/- 0.7% to 8.2% +/- 1.2%, P < 0.001 from the muffins given with orange juice compared with muffins given with apple juice. The absorption of ferrous fumarate given with orange juice and enhancement of absorption by the presence of juice were significantly positively related to height, weight, and age (P < 0.01 for each). Although iron absorption from ferrous fumarate given with apple juice was significantly inversely associated with the (log transformed) serum ferritin, the difference in absorption between juice types was not (P > 0.9).

CONCLUSIONS

These data demonstrate an overall benefit to iron absorption from ferrous fumarate provided with orange juice. The effect was age related such that in children older than 6 years of age, there was a nearly 2-fold increase in iron absorption from ferrous fumarate given with orange juice.

Bis(3-hydroxy-pyridinium) fumarate

The crystal structure of the title compound, 2C(5)H(6)NO(2) (+)·C(4)H(2)O(4) (2-), consists of 3-hydroxy-pyridinium cations and fumarate dianions. The dianion is located on an inversion center and the cation is linked to it by O-H⋯O and N-H⋯O hydrogen bonds. The cation is twisted with respect to the anion by 24.83 (5)°.

4-Acetyl-pyridine-fumaric acid (2/1)

In the crystal structure of the title cocrystal, 2C(7)H(7)NO·C(4)H(4)O(4), the complete fumaric acid mol-ecule is generated by a crystallographic inversion centre. The two components of the cocrystal are linked by an O-H⋯N hydrogen bond.

Regular consumption of a complementary food fortified with ascorbic acid and ferrous fumarate or ferric pyrophosphate is as useful as ferrous sulfate in maintaining hemoglobin concentrations >105 g/L in young Bangladeshi children

BACKGROUND

Non-water-soluble iron compounds have been reported to be less well absorbed than ferrous sulfate in young children, and concern has been raised about their usefulness as food fortificants.

OBJECTIVE

The objective was to evaluate the usefulness of ferrous fumarate and ferric pyrophosphate, compared with ferrous sulfate, in maintaining hemoglobin concentrations >105 g/L in Bangladeshi children.

DESIGN

Two hundred thirty-five children aged 7-24 mo (hemoglobin >105 g/L) were randomly assigned in a double-blind study to receive an infant cereal fortified with ferrous fumarate, ferric pyrophosphate, or ferrous sulfate. One serving of cereal (9.3 mg Fe; molar ratio of ascorbic acid to iron of 3:1) was consumed per day, 6 d/wk, for 9 mo. Blood samples were drawn at 4.5 and 9 mo.

RESULTS

Raw data were reformatted, and a "time to event" was calculated that corresponded to reaching the following thresholds: hemoglobin <105 g/L, plasma ferritin <12 microg/L, or plasma C-reactive protein >10 mg/L at baseline, 4.5 mo, or 9 mo. Data were censored when children did not reach the threshold or were lost to follow-up. A Kaplan-Meier approach was used to compare the 3 groups. No statistically significant differences were observed for hemoglobin <105 g/L (P = 0.943), plasma ferritin <12 microg/L (P = 0.601), or plasma C-reactive protein >10 mg/L (P = 0.508).

CONCLUSIONS

Contrary to earlier concerns, these results do not indicate differences in usefulness between water-soluble and non-water-soluble iron compounds in maintaining hemoglobin concentrations and preventing iron deficiency. These data will be important in the development of food-fortification strategies to combat anemia and iron deficiency in highly vulnerable population groups.

Isotope ratio measurements of iron in blood samples by multi-collector ICP-MS to support nutritional investigations in humans

With the perspective of embarking on a human study using a double iron (Fe) stable isotope tracer protocol to assess iron bioavailability, investigations were conducted on Fe isotope ratios in blood samples using a VG Axiom Multi-collector ICP-MS. The factors affecting the precision and accuracy of Fe isotopic ratios, such as spectral- and matrix-induced interferences and Fe recoveries from sample preparation, have been identified and optimized. Major polyatomic interferences (e.g., Ar-O, Ar-OH, and FeH) were significantly reduced by using an Aridus nebulizer and desolvating system. Isobaric metal (e.g., (54)Cr(+) on (54)Fe(+) and (58)Ni(+) on (58)Fe(+)) interferences and Ca-oxides and hydroxides were quantitatively removed during chemical purification of blood samples and selective isolation of Fe by anion-exchange resin, after mineralization of the blood samples by microwave digestion. Quantitative recoveries of Fe from different steps of sample preparation were verified using whole blood reference material. Fe isotopic compositions of the samples were corrected for instrumental mass bias by the standard-sample bracketing method using the certified reference standard IRMM-014. External precisions on the order of 0.008-0.05 (% RSD), 0.007-0.015 (% RSD), and 0.03-0.09 (% RSD) were obtained for (54)Fe/(56)Fe, (57)Fe/(56)Fe, and (58)Fe/(56)Fe, respectively, in the blood for three replicate measurements. The level of precision obtained in this work enables the detection of low enrichments of Fe in blood, which is highly desired in nutrition tracer studies.

Newer strategies for anemia prevention in hemodialysis

Anemia prevention for hemodialysis relies primarily on supplemental erythropoietin (EPO) and intravenous iron (IV-iron). The doses of EPO utilized are somewhat higher than normal endogenous rates of EPO production in healthy subjects, and the amount of IV-iron used to boost red blood cell (RBC) production may be greater than the amounts used for erythropoiesis. EPO and IV-iron might be used more efficiently if two fundamental problems were solved in the management of dialysis patients: better vitamin C status, and avoidance of chronic inflammation. The low levels of plasma vitamin C commonly observed in dialysis patients restrict mobilization of stored iron from the reticuloendothelial system (RES), and inflammation has a very similar effect. The impact of low vitamin C levels and concurrent inflammation causes a large amount of iron to be stored, with relatively inefficient utilization for erythropoiesis. Vitamin C intake for dialysis patients is often restricted because of avoidance of vitamin C-rich foods, and because of concerns about oxalosis. Inflammation is a chronic feature of renal disease, which is compounded by infections from use of catheters. Research strategies to improve vitamin C status and to decrease inflammation would lead to better utilization of iron and EPO, and could have parallel benefits for the long-term health of patients on hemodialysis.

Vitamin C neglect in hemodialysis: sailing between Scylla and Charybdis

In our efforts to meet the vitamin C requirements of dialysis patients we confront a medical dilemma--do we allow the patient to become depleted of vitamin C, with the accompanying hematological and other consequences (Scylla), or do we provide for adequate tissue levels of vitamin C, which has been thought to carry the risk of oxalosis (Charybdis). Many practitioners are certain that either one outcome (deficiency) or the other (oxalic acid toxicity) is inevitable, and much like Odysseus, no safe course is to be found. The recent accumulating evidence that vitamin C improves the management of anemia in dialysis patients compels us to find a safe passage through this dilemma. The serious vitamin C deficiency seen in many patients may also contribute to poor oral health and chronic fatigue. The evidence for oxalosis from vitamin C supplements stems from hemodialysis as practiced 20 years ago. Investigators using this therapy are not observing systemic oxalosis, and the most current data support the conclusion that vitamin C therapy is safe for dialysis patients. The question will be resolved by controlled trials that address both vitamin C effectiveness and safety.

Demonstrating zinc and iron bioavailability from intrinsically labeled microencapsulated ferrous fumarate and zinc gluconate Sprinkles in young children

Nutrient-nutrient interactions are an important consideration for any multiple-micronutrient formulation, including Sprinkles, a home-fortification strategy to control anemia. The objectives of this randomized controlled trial were as follows: 1) to compare the absorption of zinc at 2 doses given as Sprinkles; and 2) to examine the effect of zinc and ascorbic acid (AA) on iron absorption from Sprinkles. Seventy-five children aged 12-24 mo were randomly assigned to the following groups: 1) 5 mg of labeled zinc (67Zn) with 50 mg AA (LoZn group); b) 10 mg of labeled zinc (67Zn) with 50 mg AA (HiZn group); or 3) 5 mg zinc with no AA (control). All groups contained 30 mg of labeled iron (57Fe). Intravenous infusions labeled with 70Zn (LoZn and HiZn groups) and 58Fe (control) were administered. Blood was drawn at baseline, 48 h and 14 d later. The percentage of zinc absorbed did not differ between LoZn (geometric mean = 6.4%; min-max: 1.7-14.6) and HiZn (geometric mean = 7.5%; min-max: 3.3-18.0) groups. However, total zinc absorbed was significantly different between the LoZn (geometric mean = 0.31 mg; min-max: 0.08-0.73) and HiZn (geometric mean = 0.82 mg; min-max: 0.33-1.82) groups (P = 0.0004). Geometric mean percentage iron absorption values did not differ between the LoZn (5.9%; min-max: 0.8-21) and HiZn (4.4%; min-max: 0.6-12.3) groups and between the LoZn and control groups (5.0%; min-max: 1.4-24). We conclude that zinc in the form of Sprinkles has a low bioavailability, yet provides adequate amounts of absorbed zinc in young children, and that there is no effect of zinc or AA on iron absorption from the given formulations of Sprinkles.

Iron availability: An updated review

Iron is an essential trace element in human nutrition and its deficiency is a world nutritional problem. Due to the high prevalence of anaemia in developing and industrialized countries, it is necessary to maintain a suitable iron intake through diet in order to achieve an appropriate status of this element in the body. For this reason, accurate knowledge of iron availability of foods is essential in order to plan intervention strategies that improve deficient situations of this nutrient. Regarding to the two forms of iron present in foods, heme iron has greater availability than non-heme iron. Beside this, non-heme iron availability is conditioned by several dietary factors, such as classic factors (meat, ascorbic acid, fibre, phytic acid, polyphenols) and new factors (caseinophosphopeptides and fructo-oligosaccharides with prebiotic characteristics). For that reason, the aim of this paper is to accurately review all investigations reported in the past decade related to dietetic factors that influence the bioavailability of different iron forms.

Sodium iron EDTA [NaFe(III)EDTA] as a food fortificant: erythrocyte incorporation of iron and apparent absorption of zinc, copper, calcium, and magnesium from a complementary food based on wheat and soy in healthy infants

BACKGROUND

Phytic acid is a strong inhibitor of iron absorption from fortified foods. In adults, this inhibitory effect can be overcome by adding ascorbic acid with the iron fortificant or by using a "protected" iron compound such as NaFeEDTA. In addition, the use of NaFeEDTA as an iron fortificant has been reported to increase zinc absorption in adult women. No information is available on iron bioavailability from NaFeEDTA or the influence of NaFeEDTA on minerals and trace elements in infants.

OBJECTIVE

We aimed to compare iron bioavailability from a complementary food based on wheat and soy fortified with either NaFeEDTA or ferrous sulfate plus ascorbic acid. The apparent absorption of zinc, copper, calcium, and magnesium was evaluated in parallel.

DESIGN

Stable-isotope techniques were used in a crossover design to evaluate erythrocyte incorporation of iron 14 d after administration of labeled test meals and the apparent absorption of zinc, copper, calcium, and magnesium on the basis of fecal monitoring in 11 infants.

RESULTS

Geometric mean erythrocyte incorporation of iron was 3.7% (NaFeEDTA) and 4.9% (ferrous sulfate plus ascorbic acid) (P = 0.08). No significant differences in the apparent absorption of zinc, copper, calcium, or magnesium were observed between test meals (n = 10).

CONCLUSIONS

Iron bioavailability from a high-phytate, cereal-based complementary food fortified with either NaFeEDTA or ferrous sulfate plus ascorbic acid was not significantly different. NaFeEDTA did not influence the apparent absorption of zinc, copper, calcium, or magnesium. NaFeEDTA does not provide any nutritional benefit compared with the combination of a highly bioavailable iron compound and ascorbic acid.