Expert recommendations for the management of iron deficiency in patients with heart failure in Asia

BACKGROUND

Iron deficiency is a common comorbidity in heart failure (HF) and is independently associated with a worse quality-of-life and exercise capacity, as well as increased risk of hospitalization, regardless of anemia status. Although international guidelines have provided recommendations for the management of iron deficiency in patients with HF, guidelines in Asia are less established, and practical use of guidelines for management of iron deficiency is limited in the region.

METHODS

A panel comprising cardiologists from China, Hong Kong, India, Japan, Malaysia, Pakistan, Philippines, Singapore, South Korea, Taiwan, and Thailand convened to share insights and provide guidance for the optimal management of iron deficiency in patients with HF, tailored for the Asian community.

RESULTS

Expert opinions were provided for the screening, diagnosis, treatment and monitoring of iron deficiency in patients with HF. It was recommended that all patients with HF with reduced ejection fraction should be screened for iron deficiency, and iron-deficient patients should be treated with intravenous iron. Monitoring of iron levels in patients with HF should be carried out once or twice yearly. Barriers to the management of iron deficiency in patients with HF in the region include low awareness of iron deficiency amongst general physicians, lack of reimbursement for screening and treatment, and lack of proper facilities for administration of intravenous iron.

CONCLUSIONS

These recommendations provide a structured approach to the management of iron deficiency in patients with HF in Asia.

Intravenous iron in patients with iron deficiency and heart failure: a review of modern evidence

PURPOSE OF REVIEW

Iron deficiency is common in patients with heart failure, affecting up to half of ambulatory patients and an even greater percentage of patients admitted for acute decompensation. Iron deficiency in this population is also associated with poor outcomes, including worse quality of life in addition to increased hospitalizations for heart failure and mortality. Evidence suggests that patients with iron deficiency in heart failure may benefit from repletion with IV iron.

RECENT FINDINGS

In this review, we outline the etiology and pathophysiology of iron deficiency in heart failure as well as various iron formulations available. We discuss evidence for intravenous iron repletion with a particular focus on recent studies that have evaluated its effects on hospitalizations and mortality. Finally, we discuss areas of uncertainty and future study and provide practical guidance for iron repletion.

SUMMARY

In summary, there is overwhelming evidence that intravenous iron repletion in patients with iron deficiency in heart failure is both beneficial and safe. However, further evidence is needed to better identify which patients would most benefit from iron repletion as well as the ideal repletion strategy.

Iron status and hemoglobin adjustment by altitude to define anemia in children aged 6 to 8 months living in Lima, Arequipa, Cusco and Puno

OBJECTIVE.

To describe the iron status profile and to propose hemoglobin adjustment factors for altitude for children aged 6 to 8 months in Lima, Arequipa, Cusco and Puno.

MATERIALS AND METHODS.

Cross-sectional study in children aged 6 to 8 months from four cities. We measured hemoglobin and other iron biomarkers, C-reactive protein (CRP), among others. To estimate the adjustment equation, we applied an exponential regression. We excluded children with iron deficiency (ID) and/or inflammation.

RESULTS.

The proportions of ID were higher in Puno and Arequipa, while inflammation did not exceed 19% in any of the cities. Hemoglobin showed an exponential increase at higher altitude. The adjustment equation was: 10.34249 x (1.00007 ^ Alt).

CONCLUSIONS.

Children residing in Arequipa and Puno showed higher rates of ID and lower iron reserves; furthermore, the increase in hemoglobin by altitude was exponential, showing the need to adjust hemoglobin at altitude.

Regulation of translation in response to iron deficiency in human cells

Protein synthesis is a highly energy-consuming process that is downregulated in response to many environmental stresses or adverse conditions. Studies in the yeast Saccharomyces cerevisiae have shown that bulk translation is inhibited during adaptation to iron deficiency, which is consistent with its requirement for ribosome biogenesis and recycling. Although iron deficiency anemia is the most common human nutritional disorder, how iron modulates translation in mammals is poorly understood. Studies during erythropoiesis have shown that iron bioavailability is coordinated with globin synthesis via bulk translation regulation. However, little is known about the control of translation during iron limitation in other tissues. Here, we investigated how iron depletion affects protein synthesis in human osteosarcoma U-2 OS cells. By adding an extracellular iron chelator, we observed that iron deficiency limits cell proliferation, induces autophagy, and decreases the global rate of protein synthesis. Analysis of specific molecular markers indicates that the inhibition of bulk translation upon iron limitation occurs through the eukaryotic initiation factor eIF2α and mechanistic target of rapamycin (mTOR) pathways. In contrast to other environmental and nutritional stresses, iron depletion does not trigger the assembly of messenger ribonucleoprotein stress granules, which typically form upon polysome disassembly.

Biomarkers of Brain Dysfunction in Perinatal Iron Deficiency

Iron deficiency in the fetal and neonatal period (perinatal iron deficiency) bodes poorly for neurodevelopment. Given its common occurrence and the negative impact on brain development, a screening and treatment strategy that is focused on optimizing brain development in perinatal iron deficiency is necessary. Pediatric societies currently recommend a universal iron supplementation strategy for full-term and preterm infants that does not consider individual variation in body iron status and thus could lead to undertreatment or overtreatment. Moreover, the focus is on hematological normalcy and not optimal brain development. Several serum iron indices and hematological parameters in the perinatal period are associated with a risk of abnormal neurodevelopment, suggesting their potential use as biomarkers for screening and monitoring treatment in infants at risk for perinatal iron deficiency. A biomarker-based screening and treatment strategy that is focused on optimizing brain development will likely improve outcomes in perinatal iron deficiency.

Erythroferrone and hepcidin levels in children with iron deficiency anemia

BACKGROUND

Iron deficiency anemia remains a significant public health issue in developing countries. The regulation of iron metabolism is primarily controlled by hepcidin, a key regulatory protein. During erythropoiesis, erythroferrone (ERFE), a hormone produced by erythroblasts in response to erythropoietin (EPO) synthesis, mediates the suppression of hepcidin. In this study, it was aimed to determine the correlation between erythroferrone (ERFE) and hepcidin levels in children with iron deficiency anemia.

METHODS

This is a case-control study conducted at Kırşehir Ahi Evran University Training and Research Hospital Pediatrics Clinic between 1 and 31 September 2020. The study included 26 healthy children and 26 children with iron deficiency anemia. In order to evaluate iron status,whole blood count, serum iron, total iron binding capacity (TIBC), and ferritin levels were analyzed. The study measured the levels of hepcidin and erythroferrone in the serum of children diagnosed with iron deficiency before and after one month of iron treatment, as well as in a control group, using the ELISA method. Correlation between whole blood count, initial ferritin, hepcidin, ERFE and ferritin in the iron deficiency group was evaluated.

RESULTS

Compared with healthy controls, the iron-deficient group had significantly lower haemoglobin (p < 0.001), MCV (p = 0.001), MCH (p < 0.001), MCHC (p < 0.001), iron (p < 0.001), ferritin (p < 0.001) and hepcidin (p = 0.001). Ferritin and hepcidin levels increased while erythroferrone levels remained unchanged after iron deficiency treatment. There was no correlation between hepcidin and ferritin levels in treatment group.

CONCLUSIONS

The study found a strong and positive correlation between ferritin and hepcidin levels in iron-deficient children, but not between ERFE levels, suggesting that hepcidin is largely regulated by iron deposition levels. In addition, there was an increase in ferritin and hepcidin levels after iron treatment. The study found no significant difference in erythroferrone levels between the iron-deficient group and the control group. It is thought that this may be due to the short duration of iron treatment given to the patients with iron deficiency anemia included in the study.

Iron deficiency at birth and risk of hidden hearing loss in infants modification by socioeconomic status: mother-newborn cohort in Shenyang, China

OBJECTIVE

The diagnosis of hidden hearing loss (HHL) in calm state has not yet been determined, while the nutritional status is not involved in its pathogenic risk factors. In utero iron deficiency (ID) may delay auditory neural maturation in infants. We evaluated the association between ID and HHL as well as the modification effect of socioeconomic status (SES) on this association in newborns.

STUDY DESIGN

We included 859 mother-newborns from the baseline of this observational northeast cohort. Data on exposure assessment included iron status [maternal hemoglobin (Hb) and neonatal heel prick serum ferritin (SF)] and SES (occupation, education and income). Auditory neural maturation was reflected by auditory brainstem response (ABR) testing and electrocochleography (ECochG).

RESULTS

Iron status and SES were independently and jointly associated with the prediction of neonatal HHL by logistic and linear regression model. The mediation effects were performed by Process. ID increased absolute latency wave V, interpeak latency (IPL) III-V, and summting potentials (SP) /action potentials (AP), which were combined as HHL. Low SES showed the highest risk of HHL and the highest levels of related parameters in ID newborns. Moreover, after Corona Virus Disease 2019 (COVID-19) were positive, preschool children who experience ID in neonatal period were more likely to suffer from otitis media with effusion (OME). High SES also showed similar risk effects.

CONCLUSION

Both low and high SES may strengthen the risk of ID on neonatal HHL in Northeast China.

Management of iron deficiency in women of childbearing age with oral iron intolerance: a prospective, randomised, controlled trial of three doses of an iron-whey-protein formulation : Prospective RandomisEd study of women of Childbearing age with gastroInteStinal Intolerance to Oral iroN (PRECISION)

BACKGROUND

Nutritional deficit and oral iron gastrointestinal intolerance may be a common cause of iron deficiency, which can be managed by pharmacists.

AIM

To understand the prevalence of iron deficiency in women of childbearing age with a self-reported history of intolerance to oral iron and the tolerability of three doses of an iron-whey-protein formulation in the care of these women.

METHOD

Ferritin and haemoglobin levels were documented in women of childbearing age with oral iron gastrointestinal intolerance. In those with iron deficiency (ferritin < 30 µg/L), adherence, gastrointestinal tolerability, ferritin, transferrin saturation and haemoglobin levels were compared between their prior oral iron product and iron-whey-protein microspheres randomised to three doses (14 mg daily, 25 mg daily and 50 mg daily) for 12 weeks.

RESULTS

Most screened women had low iron stores (128 (62.7%); ferritin < 30 µg/L), 65 (31.9%) had moderate to severe iron deficiency (ferritin < 12 µg/L) and 33 (16.2%) had iron deficiency anaemia (ferritin < 30 µg/L, haemoglobin < 12 g/dL). Amongst the 59 women who participated in the prospective clinical study of iron-whey-protein microspheres over 12 weeks, 48 (81.4%) were classified as adherent/persistent and fewer instances of gastrointestinal intolerance were reported (0.59 ± 0.91) when compared to 12 (20.3%) and (4.0 ± 2.2) respectively while taking the prior oral iron (Fisher's Exact and T-test respectively, both p < 0.001). There was no difference in adherence or tolerability of different iron-whey-protein formulation doses. Ferritin, haemoglobin and energy levels increased significantly over 12 weeks.

CONCLUSION

Undiagnosed iron deficiency is common in women of childbearing age with a history of intolerance to oral iron and iron-whey-protein microspheres can improve adherence, GI tolerability, iron stores, haemoglobin and energy levels in these women.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov identifier (registration includes full trial protocol): NCT04778072.

Iron Deficiency in Anemic Children Surviving Critical Illness: Post Hoc Analysis of a Single-Center Prospective Cohort in Canada, 2019-2022

OBJECTIVES

Many children leave the PICU with anemia. The mechanisms of post-PICU anemia are poorly investigated, and treatment of anemia, other than blood, is rarely started during PICU. We aimed to characterize the contributions of iron depletion (ID) and/or inflammation in the development of post-PICU anemia and to explore the utility of hepcidin (a novel iron marker) at detecting ID during inflammation.

DESIGN

Post hoc analysis of a single-center prospective study (November 2019 to September 2022).

SETTING

PICU, quaternary center, Canada.

PATIENTS

Children admitted to PICU with greater than or equal to 48 hours of invasive or greater than or equal to 96 hours of noninvasive ventilation. We excluded patients with preexisting conditions causing anemia or those admitted after cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Hematological and iron profiles were performed at PICU discharge on 56 participants of which 37 (37/56) were diagnosed with anemia. Thirty-three children (33/56; 59%) were younger than 2 years. Median Pediatric Logistic Organ Dysfunction score was 11 (interquartile range, 6-16). Twenty-four of the 37 anemic patients had repeat bloodwork 2 months post-PICU. Of those, four (4/24; 16%) remained anemic. Hematologic profiles were categorized as: anemia of inflammation (AI), iron deficiency anemia (IDA), IDA with inflammation, and ID (low iron stores without anemia). Seven (7/47; 15%) had AI at discharge, and one had persistent AI post-PICU. Three patients (3/47; 6%) had IDA at discharge; of which one was lost to follow-up and the other two were no longer anemic but had ID post-PICU. Eleven additional patients developed ID post-PICU. In the exploratory analysis, we identified a diagnostic cutoff value for ID during inflammation from the receiver operating characteristic curve for hepcidin of 31.9 pg/mL. This cutoff would increase the detection of ID at discharge from 6% to 34%.

CONCLUSIONS

The burden of ID in children post-PICU is high and better management strategies are required. Hepcidin may increase the diagnostic yield of ID in patients with inflammation.

Exercise training response according to baseline ferrokinetics in heart failure with preserved ejection fraction: A substudy of the TRAINING-HF trial

BACKGROUND

Iron deficiency (ID) is associated with impaired functional capacity in patients with heart failure (HF), even in those with preserved ejection fraction (HFpEF). This study aimed to evaluate the effect of baseline ferrokinetics on peak oxygen consumption (peakVO2) improvement after a 12-week physical therapy programme in patients with stable HFpEF.

METHODS

This study is a post-hoc sub-analysis of a randomized clinical trial in which 59 stable patients with HFpEF were randomized to receive a 12-week programme of inspiratory muscle training (IMT), functional electrical stimulation (FES), IMT + FES or usual care (UC) to evaluate change in peakVO2 (NCT02638961). Serum ferritin and transferrin saturation (TSAT) determinations were assessed at baseline. ID was defined as ferritin <100 ng/mL and/or TSAT <20% if ferritin was within 100-299 ng/mL. We used a linear mixed regression model to analyse between-treatment changes in peakVO2 across ferrokinetics status at 12 and 24 weeks.

RESULTS

The mean age was 74 ± 9 years, and 36 (61%) had ID. The mean of peakVO2 was 9.9 ± 2.5 mL/kg/min. The median of ferritin and transferrin saturation (TSAT) was 91 (50-181) ng/mL and 23% (16-30), respectively. A total of 52 patients completed the trial (13 patients per arm). Compared with those patients on UC, patients allocated to any of the active arms showed less improvement in peak VO2 when they showed ID (P-value for interaction <0.001), lower values of ferritin (P-value for interaction <0.001), or TSAT (P-value for interaction <0.001).

CONCLUSIONS

Ferrokinetics status plays an essential role in modifying the aerobic capacity response to physical therapies in patients with HFpEF. Further studies are required to confirm these findings.

Daily versus three times weekly dosing for treatment of iron deficiency nonanemia in NCAA Division 1 female athletes

OBJECTIVE

To compare the effectiveness, compliance, and side effect profile between daily or three times weekly (TIW) oral iron supplementation regimens in treating iron deficiency nonanemia (IDNA) in National Collegiate Athletic Association (NCAA) Division 1 female track and field or soccer athletes.

DESIGN

Prospective cohort study.

SETTING

Division 1 collegiate athletics.

PARTICIPANTS

Thirty-three NCAA Division 1 female athletes (18 track and field, 15 soccer).

INTERVENTIONS

Daily or TIW dosing of ferrous bisglycinate.

MAIN OUTCOME MEASURES

Serum ferritin (μg/L) was measured before and after 8 weeks of supplementation. Self-reported compliance and side effect profile was assessed by electronic survey every 2 weeks.

RESULTS

The average main effect for the TIW regimen was a significant increase of 5.17 μg/L (95% CI: 0.86-9.47) in serum ferritin (p = .02). The average main effect for the daily regimen was a significant increase of 12.88 μg/L (95% CI: 4.84-20.93) in serum ferritin (p = .003). The estimated average effect of the treatment on the treated between regimens was a nonsignificant decrease of -7.17 μg/L (95% CI: -19.02 - 3.59) in serum ferritin (p = .17). Thus, the TIW regimen increased serum ferritin 7.17 units less than the daily regimen on average after 8 weeks of supplementation. The athletes following the daily regimen experienced significantly more nausea (p = .04) and constipation (p = .002) compared to the TIW regimen. There was no statistical difference in compliance between the two groups (p = .14).

CONCLUSIONS

Both the daily and TIW regimens increased serum ferritin. Compared to the daily regimen, the TIW regimen produced a smaller increase in serum ferritin but less nausea and constipation.

Identification of Genes Responding to Iron or Choline Treatment for Early-Life Iron Deficiency in the Male Rat Hippocampal Transcriptomes

BACKGROUND

Developmental iron deficiency (ID) is associated with long-term cognitive and affective behavioral impairments in humans. Preclinical studies have shown that developmental ID has short- and long-term effects on gene regulation. Prenatal choline supplementation partially rescues early-life ID-induced cognitive deficits in adult male rats.

OBJECTIVES

To identify acute and long-term changes in biological processes regulated by developmental ID and modifiable by choline.

METHODS

This study compares the hippocampal transcriptomes of postnatal day (P) 15 iron-deficient (acute) and P65 formerly ID (persistent) rats with or without prenatal choline treatment. Pregnant rats were fed an ID (4 mg/kg Fe) or iron-sufficient (IS) (200 mg/kg Fe) diet from gestational day (G) 2 to P7 with or without choline supplementation (5 g/kg choline) from G11 to G18. Hippocampi were collected from P15 or P65 offspring and analyzed for gene expression by RNA sequencing.

RESULTS

Developmental ID-induced changes suggested modified activity of oxidative phosphorylation and fatty acid metabolism. Prenatal choline supplementation induced robust changes in gene expression, particularly in iron-deficient animals, where it partially mitigated the early-life ID-dysregulated genes. Choline supplementation also altered the hippocampal transcriptome in the IS rats, with indications for both beneficial and adverse effects.

CONCLUSIONS

This study provided global assessments of gene expression regulated by iron and choline. Our new findings highlight genes responding to iron or choline treatments, including a potentially novel choline-regulated transporter (IPO7), with shared effects on neuroinflammation in the male rat hippocampus.

Associations of fish and meat intake with iron and anaemia in Malawian children

Animal flesh foods are rich in bioavailable iron but infrequently consumed by young children. We aimed to determine whether flesh food intake was associated with iron and anaemia status among 585 Malawian infants enroled in a 6-month egg-feeding trial. The percentage of days of small fish, large fish and meat consumption were assessed through weekly 7-day animal-source food screeners. Grams of intake were assessed through 24-h recalls conducted at 6-9, 9-12 and 12-15 months of age. Plasma ferritin, soluble transferrin receptor (sTfR) and haemoglobin concentrations were measured at 6-9 and 12-15 months of age. Iron biomarkers were adjusted for inflammation during analysis. At enrolment, each flesh food category was consumed by <5% of children in the past 24 h. Over the next 6 months, small fish, large fish and meat were consumed on 25%, 8% and 6% of days, respectively, with mean usual intakes of <5 g/day. More frequent small fish consumption was associated with lower sTfR (geometric mean ratio [95% CI]: 0.98 mg/L [0.96, 1.00] per 10 percentage point difference) but not ferritin (1.03 µg/L [0.98, 1.07]) or haemoglobin (1.01 g/dL [1.00, 1.01]). Large fish consumption was associated with higher anaemia (prevalence ratio [95% CI]: 1.09 [1.01, 1.19]) and lower iron deficiency (0.96 [0.93, 1.00]) prevalence. Gram intakes of flesh food categories were not associated with any iron or anaemia indicators. Small fish were a primary contributor to flesh food intake in this cohort of Malawian children, although usual portions were small. Fish was associated with modest improvements to iron status, but meat was too infrequent to be associated with anaemia and iron deficiency.

Molecular insights into the mutualism that induces iron deficiency tolerance in sorghum inoculated with Trichoderma harzianum

Iron (Fe) deficiency is a common mineral stress in plants, including sorghum. Although the soil fungus Trichoderma harzianum has been shown to mitigate Fe deficiency in some circumstances, neither the range nor mechanism(s) of this process are well understood. In this study, high pH-induced Fe deficiency in sorghum cultivated in pots with natural field soil exhibited a significant decrease in biomass, photosynthetic rate, transpiration rate, stomatal conductance, water use efficiency, and Fe-uptake in both the root and shoot. However, the establishment of T. harzianum colonization in roots of Fe-deprived sorghum showed significant improvements in morpho-physiological traits, Fe levels, and redox status. Molecular detection of the fungal ThAOX1 (L-aminoacid oxidase) gene showed the highest colonization of T. harzianum in the root tips of Fe-deficient sorghum, a location thus targeted for further analysis. Expression studies by RNA-seq and qPCR in sorghum root tips revealed a significant upregulation of several genes associated with Fe uptake (SbTOM2), auxin synthesis (SbSAURX15), nicotianamine synthase 3 (SbNAS3), and a phytosiderophore transporter (SbYS1). Also induced was the siderophore synthesis gene (ThSIT1) in T. harzianum, a result supported by biochemical evidence for elevated siderophore and IAA (indole acetic acid) levels in roots. Given the high affinity of fungal siderophore to chelate insoluble Fe3+ ions, it is likely that elevated siderophore released by T. harzianum led to Fe(III)-siderophore complexes in the rhizosphere that were then transported into roots by the induced SbYS1 (yellow-stripe 1) transporter. In addition, the observed induction of several plant peroxidase genes and ABA (abscisic acid) under Fe deficiency after inoculation with T. harzianum may have helped induce tolerance to Fe-deficiency-induced oxidative stress and adaptive responses. This is the first mechanistic explanation for T. harzianum's role in helping alleviate Fe deficiency in sorghum and suggests that biofertilizers using T. harzianum will improve Fe availability to crops in high pH environments.

Analysis of related factors of CRA in lung cancer patients with different serum iron levels: A retrospective cohort study

BACKGROUND

Serum iron, an essential component of hemoglobin (Hb) synthesis in vivo, is a crucial parameter for evaluating the body's iron storage and metabolism capacity. Iron deficiency leads to reduced Hb synthesis in red blood cells and smaller red blood cell volume, ultimately resulting in iron-deficiency anemia. Although serum iron cannot independently evaluate iron storage or metabolism ability, it can reflect iron concentration in vivo and serve as a good predictor of iron-deficiency anemia. Therefore, exploring the influence of different serum iron levels on anemia and diagnosing and treating iron deficiency in the early stages is of great significance for patients with lung cancer.

AIM

This study aims to explore the related factors of cancer-related anemia (CRA) in lung cancer and construct a nomogram prediction model to evaluate the risk of CRA in patients with different serum iron levels.

METHODS

A single-center retrospective cohort study was conducted, including 1610 patients with lung cancer, of whom 1040 had CRA. The relationship between CRA and its influencing factors was analyzed using multiple linear regression models. Lung cancer patients were divided into two groups according to their serum iron levels: decreased serum iron and normal serum iron. Each group was randomly divided into a training cohort and a validation cohort at a ratio of 7:3. The influencing factors were screened by univariate and multivariate logistic regression analyses, and nomogram models were constructed. The area under the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the models.

RESULTS

CRA in lung cancer is mainly related to surgery, chemotherapy, Karnofsky Performance Status (KPS) score, serum iron, C-reactive protein (CRP), albumin, and total cholesterol (p < 0.05). CRA in lung cancer patients with decreased serum iron is primarily associated with albumin, age, and cancer staging, while CRA in lung cancer patients with normal serum iron is mainly related to CRP, albumin, total cholesterol, and cancer staging. The area under the ROC curve of the training cohort and validation cohort for the prediction model of lung cancer patients with decreased serum iron was 0.758 and 0.760, respectively. Similarly, the area under the ROC curve of the training cohort and validation cohort for the prediction model of lung cancer patients with normal serum iron was 0.715 and 0.730, respectively. The calibration curves of both prediction models were around the ideal 45° line, suggesting good discrimination and calibration. DCA showed that the nomograms had good clinical utility.

CONCLUSION

Both models have good reliability and validity and have significant clinical value. They can help doctors better assess the risk of developing CRA in lung cancer patients. CRP is a risk factor for CRA in lung cancer patients with normal serum iron but not in patients with decreased serum iron. Therefore, whether CRP and the inflammatory state represented by CRP will further aggravate the decrease in serum iron levels, thus contributing to anemia, warrants further study.

Maize gets an iron boost: Biofortification breakthrough holds promise to combat iron deficiency

This commentary describes recent research discovering that the NAC transcription factor gene ZmNAC78 controls iron intake in maize and its implications for biofortification of this important crop. Using ZmNAC78, iron levels in maize can be more than doubled compared with current varieties.

Iron deficiency in pernicious anemia: Specific features of iron deficient patients and preliminary data on response to iron supplementation

BACKGROUND & AIMS

While vitamin B12 (B12) deficiency is considered as the hallmark of pernicious anemia (PA), iron deficiency (ID) is also prevalent. Indeed, this auto immune gastritis is responsible for parietal cell atrophy and increase in gastric pH, leading to impaired iron absorption. We compared PA patients' features according to their iron status at PA diagnosis, and we assessed the iron status recovery after oral or intravenous iron supplementation.

METHODS

We prospectively included patients presenting with a newly diagnosed PA in a tertiary referral hospital between November 2018 and October 2020. Iron status was assessed at PA diagnosis then regularly during a standardized follow-up. In case of ID, the decision of treatment with oral and/or intravenous iron supplementation was left to the clinician convenience.

RESULTS

We included 28 patients with newly diagnosed PA. ID was observed in 21/28 (75.0%) patients: from the PA diagnosis in 13 patients, or during the follow-up in 8 patients. Iron deficient PA patients had higher plasma B12 (p = 0.04) and lower homocysteine levels (p = 0.04). Also, ID was independently associated with the 'APCA (anti-parietal cell antibodies) alone' immunological status (absence of anti-intrinsic factor antibodies) after adjustment for age, gender and B12 level (aOR 12.1 [1.1-141.8], p = 0.04). High level of APCA was associated with lower ferritin level. After 3 months of supplementation, 3/11 PA patients normalized the iron status with oral iron supplementation, versus 7/8 with intravenous iron supplementation (p = 0.02).

CONCLUSION

The high frequency of iron deficiency in PA highlights the interest of regular assessment of iron status in this condition. ID was associated with a profile including APCA alone and less pronounced B12 deficiency. Intravenous iron supplementation seemed to be more efficient than an oral supplementation in these preliminary data.

The activation of iron deficiency responses of grapevine rootstocks is dependent to the availability of the nitrogen forms

BACKGROUND

In viticulture, iron (Fe) chlorosis is a common abiotic stress that impairs plant development and leads to yield and quality losses. Under low availability of the metal, the applied N form (nitrate and ammonium) can play a role in promoting or mitigating Fe deficiency stresses. However, the processes involved are not clear in grapevine. Therefore, the aim of this study was to investigate the response of two grapevine rootstocks to the interaction between N forms and Fe uptake. This process was evaluated in a hydroponic experiment using two ungrafted grapevine rootstocks Fercal (Vitis berlandieri x V. vinifera) tolerant to deficiency induced Fe chlorosis and Couderc 3309 (V. riparia x V. rupestris) susceptible to deficiency induced Fe chlorosis.

RESULTS

The results could differentiate Fe deficiency effects, N-forms effects, and rootstock effects. Interveinal chlorosis of young leaves appeared earlier on 3309 C from the second week of treatment with NO3-/NH4+ (1:0)/-Fe, while Fercal leaves showed less severe symptoms after four weeks of treatment, corresponding to decreased chlorophyll concentrations lowered by 75% in 3309 C and 57% in Fercal. Ferric chelate reductase (FCR) activity was by trend enhanced under Fe deficiency in Fercal with both N combinations, whereas 3309 C showed an increase in FCR activity under Fe deficiency only with NO3-/NH4+ (1:1) treatment. With the transcriptome analysis, Gene Ontology (GO) revealed multiple biological processes and molecular functions that were significantly regulated in grapevine rootstocks under Fe-deficient conditions, with more genes regulated in Fercal responses, especially when both forms of N were supplied. Furthermore, the expression of genes involved in the auxin and abscisic acid metabolic pathways was markedly increased by the equal supply of both forms of N under Fe deficiency conditions. In addition, changes in the expression of genes related to Fe uptake, regulation, and transport reflected the different responses of the two grapevine rootstocks to different N forms.

CONCLUSIONS

Results show a clear contribution of N forms to the response of the two grapevine rootstocks under Fe deficiency, highlighting the importance of providing both N forms (nitrate and ammonium) in an appropriate ratio in order to ease the rootstock responses to Fe deficiency.

Iron deficiency, iron deficiency anaemia and anaemia of inflammation - an overview

Iron is an essential trace element for various cellular proteins and for biological processes in all cells. Severe iron deficiency (ID) impairs haem synthesis, reduces erythropoiesis and causes iron deficiency anaemia (IDA). Iron restriction in anaemia of inflammation is mainly due to retention of iron in macrophages. This condition is known as 'functional iron deficiency'. A review of studies performed in Europe shows that the prevalence of ID and IDA in young children varies by region. It is more common in eastern than western European countries. This overview summarises information on the need for iron supplementation in children, and the current understanding of the regulatory mechanisms of iron homeostasis and ironrestricted erythropoiesis. The causes of anaemia during infection and the usefulness of classical and new indicators to distinguish absolute from functional iron deficiency are discussed.

Chromatin accessibility and H3K9me3 landscapes reveal long-term epigenetic effects of fetal-neonatal iron deficiency in rat hippocampus

BACKGROUND

Iron deficiency (ID) during the fetal-neonatal period results in long-term neurodevelopmental impairments associated with pervasive hippocampal gene dysregulation. Prenatal choline supplementation partially normalizes these effects, suggesting an interaction between iron and choline in hippocampal transcriptome regulation. To understand the regulatory mechanisms, we investigated epigenetic marks of genes with altered chromatin accessibility (ATAC-seq) or poised to be repressed (H3K9me3 ChIP-seq) in iron-repleted adult rats having experienced fetal-neonatal ID exposure with or without prenatal choline supplementation.

RESULTS

Fetal-neonatal ID was induced by limiting maternal iron intake from gestational day (G) 2 through postnatal day (P) 7. Half of the pregnant dams were given supplemental choline (5.0 g/kg) from G11-18. This resulted in 4 groups at P65 (Iron-sufficient [IS], Formerly Iron-deficient [FID], IS with choline [ISch], and FID with choline [FIDch]). Hippocampi were collected from P65 iron-repleted male offspring and analyzed for chromatin accessibility and H3K9me3 enrichment. 22% and 24% of differentially transcribed genes in FID- and FIDch-groups, respectively, exhibited significant differences in chromatin accessibility, whereas 1.7% and 13% exhibited significant differences in H3K9me3 enrichment. These changes mapped onto gene networks regulating synaptic plasticity, neuroinflammation, and reward circuits. Motif analysis of differentially modified genomic sites revealed significantly stronger choline effects than early-life ID and identified multiple epigenetically modified transcription factor binding sites.

CONCLUSIONS

This study reveals genome-wide, stable epigenetic changes and epigenetically modifiable gene networks associated with specific chromatin marks in the hippocampus, and lays a foundation to further elucidate iron-dependent epigenetic mechanisms that underlie the long-term effects of fetal-neonatal ID, choline, and their interactions.

Determinants of iron-rich food deficiency among children under 5 years in sub-Saharan Africa: a comprehensive analysis of Demographic and Health Surveys

BACKGROUND

Iron deficiency is a major public health problem that affects the physical and cognitive development of children under 5 years of age (under-5 children) in sub-Saharan Africa (SSA). However, the factors associated with the limited consumption of iron-rich foods in the region are poorly understood.

OBJECTIVE

This study examined the prevalence and determinants of iron-rich food deficiency among under-5 children in 26 SSA countries.

DESIGN

This nationally representative quantitative study employed pooled data from Demographic and Health Surveys conducted between 2010 and 2019.

METHODS

Representative samples comprising 296 850 under-5 children from the various countries were used. Bivariate and multivariate logistic regression models were used to determine the associations between the lack of iron-rich food uptake and various sociodemographic factors.

RESULT

The overall prevalence of iron-rich food deficiency among the children in the entire sample was 56.75%. The prevalence of iron-rich food deficiency varied widely across the 26 countries, ranging from 42.76% in Congo Democratic Republic to 77.50% in Guinea. Maternal education, particularly primary education (OR 0.62, 95% CI 0.57 to 0.68) and higher education (OR 0.58, 95% CI 0.52 to 0.64), demonstrated a reduced likelihood of iron-rich food deficiency in the sample. Likewise, paternal education, with both primary education (OR 0.69, 95% CI 0.63 to 0.75) and higher education (OR 0.66, 95% CI 0.60 to 0.73) showed decreased odds of iron-rich food deficiency. Postnatal visits contributed significantly to reducing the odds of iron-rich food deficiency (OR 0.90, 95% CI 0.83 to 0.95), along with antenatal visits, which also had a positive impact (OR 0.84, 95% CI 0.74 to 0.95). Finally, residents in rural areas showed slightly higher odds of iron-rich food deficiency (OR 1.12, 95% CI 1.10 to 1.28).

CONCLUSION

Based on the findings, interventions targeting iron-food deficiency in the SSA region should take into strong consideration the key determinants highlighted in this study.

Iron deficiency and anemia in pediatric dilated cardiomyopathy are associated with clinical, biochemical, and hematological markers of severe disease and adverse outcomes

BACKGROUND

There is limited evidence regarding the prevalence and impact of iron deficiency (ID) in children with dilated cardiomyopathy (DCM).

METHODS

Retrospective single-center review of all children between 2010 and 2020 with a diagnosis of DCM and complete iron studies. ID was defined as ≥2 of ferritin <20 μg/liter, iron <9 μmol/liter, transferrin >3 g/liter, or transferrin saturation (TSat) <15%. Clinical and laboratory indices and freedom from a composite adverse event (CAE) of mechanical circulatory support (MCS), heart transplant, or death were compared between children with and without ID.

RESULTS

Of 138 patients with DCM, 47 had available iron studies. Twenty-nine (62%) were iron deficient. Children with ID were more likely to be receiving inotropes (17, 59%, p = 0.005) or invasive/noninvasive ventilation (13, 45%, p = 0.016) than those who were iron replete. They had a higher incidence of anemia (22, 76%, p = 0.004) and higher NT-proBNP (1,590 pmol/liter, IQR 456-3,447, p = 0.001). Children with ID had significantly less freedom from the CAE at 1-year (54% ± 10%), 2-years (45 ± 10), and 5-years (37% ± 11%) than those without (p = 0.011). ID and anemia were the only significant predictors of the CAE on univariate Cox regression.

CONCLUSIONS

ID is highly prevalent in children with DCM. Iron studies are undermeasured in clinical practice, but ID is associated with severe heart failure (HF) and an increased risk of the CAE. The need for iron replacement therapy should be considered in children who present in HF with DCM.

Hepcidin and inflammation associated with iron deficiency in childhood obesity - A systematic review

OBJECTIVES

This paper aims to review data on the association of obesity and iron deficiency in children and adolescents, exposing the possible involvement of hepcidin and interleukin-6 (IL-6), obesity's inflammation biomarkers.

DATA SOURCE

Articles from PUBMED and WEB OF SCIENCE database with no chronological limit were reviewed to write this systematic review. Keywords such as children, obesity, iron deficiency, and hepcidin were used. After deleting duplicated and review articles, 91 were screened, and 39 were selected as eligible. Sixteen articles were included because they involved serum hepcidin levels in obese children and adolescents as outcomes.

SUMMARY OF FINDINGS

Finally, those 16 articles were organized in two tables: one includes therapeutic interventions, and the other does not. As hepcidin was discovered in 2000, the first articles that presented serum hepcidin's quantification in obese children and adolescents, homeostasis iron markers, and their possible association with obesity's inflammatory environment began to be published in 2008.

CONCLUSIONS

Obesity's chronic inflammation state leads to the production of IL-6, which acts as a signaling molecule for hepcidin synthesis, resulting in iron deficiency, which is common in obese children and adolescents who respond inadequately to iron supplementation. On the other hand, that population responds adequately to therapeutic intervention programs that lead to weight loss, guaranteeing iron homeostasis improvement. Therefore, perhaps it is time to discuss serum hepcidin level quantification as part of evaluating children and adolescents with iron deficiency, which could guide clinical choices that might lead to better therapeutic outcomes.

Meta-Analysis and Metaregression of the Treatment Effect of Intravenous Iron in Iron-Deficient Heart Failure

BACKGROUND

Guidelines recommend that intravenous iron should be considered to improve symptoms of heart failure (HF) and reduce the risk for HF admissions in patients after acute HF.

OBJECTIVES

This study sought to analyze the effect of intravenous iron on cardiovascular (CV) death and HF admissions in a broad population of HF patients with iron deficiency and the relation with baseline transferrin saturation (TSAT).

METHODS

A systematic review of all published randomized controlled trials assessing the effect of intravenous iron in patients with iron deficiency and HF between January 1, 2000, and August 26, 2023, was performed. The overall treatment effect was estimated using a fixed effect model for: 1) CV death; 2) CV death and HF admission; 3) first HF admission; and 4) total HF admissions. Metaregression through a mixed effect model was used to explore the impact of baseline TSAT in case of heterogeneity among trial results.

RESULTS

A total of 14 randomized controlled trials were identified in the systematic review and retained in the meta-analysis. Aggregate-level data were included on 6,624 HF patients, 3,407 of whom were randomized to intravenous iron and 3,217 to placebo. Treatment with intravenous iron resulted in a lower risk for CV death (OR: 0.867 [95% CI: 0.755-0.955]; P = 0.0427), combined CV death and HF admission (OR: 0.838 [95% CI: 0.751-0.936]; P = 0.0015), first HF admission (OR: 0.855 [95% CI: 0.744-0.983]; P = 0.0281), and total HF admissions (rate ratio: 0.739 [95% CI: 0.661-0.827]; P < 0.0001). Significant heterogeneity among trial results was observed for first and total HF admissions. Metaregression suggested that some of the heterogeneity was related to the baseline TSAT of the enrolled population, with trials enrolling patients with lower TSAT exhibiting a large effect size on HF-related events.

CONCLUSIONS

The totality of data suggests that treatment with intravenous iron reduces both CV death and HF-related events in a broad population with HF. A lower baseline TSAT might be important for the effect on HF-related events.

Oral iron therapy: Current concepts and future prospects for improving efficacy and outcomes

Iron deficiency (ID) and iron-deficiency anaemia (IDA) are global public health concerns, most commonly afflicting children, pregnant women and women of childbearing age. Pathological outcomes of ID include delayed cognitive development in children, adverse pregnancy outcomes and decreased work capacity in adults. IDA is usually treated by oral iron supplementation, typically using iron salts (e.g. FeSO4 ); however, dosing at several-fold above the RDA may be required due to less efficient absorption. Excess enteral iron causes adverse gastrointestinal side effects, thus reducing compliance, and negatively impacts the gut microbiome. Recent research has sought to identify new iron formulations with better absorption so that lower effective dosing can be utilized. This article outlines emerging research on oral iron supplementation and focuses on molecular mechanisms by which different supplemental forms of iron are transported across the intestinal epithelium and whether these transport pathways are subject to regulation by the iron-regulatory hormone hepcidin.

Plasma Ferritin Levels, Incident Heart Failure, and Cardiac Structure and Function: The ARIC Study

BACKGROUND

Whether iron deficiency contributes to incident heart failure (HF) and cardiac dysfunction has important implications given the prevalence of iron deficiency and the availability of several therapeutics for iron repletion.

OBJECTIVES

The aim of this study was to estimate the associations of plasma ferritin level with incident HF overall, HF phenotypes, and cardiac structure and function measures in older adults.

METHODS

Participants in the ongoing, longitudinal ARIC (Atherosclerosis Risk In Communities) study who were free of prevalent HF and anemia were studied. The associations of plasma ferritin levels with incident HF overall and heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) were estimated using Cox proportional hazards regression models. Linear regression models estimated the cross-sectional associations of plasma ferritin with echocardiographic measures of cardiac structure and function.

RESULTS

The cohort included 3,472 individuals with a mean age of 75 ± 5 years (56% women, 14% Black individuals). In fully adjusted models, lower ferritin was associated with higher risk for incident HF overall (HR: 1.20 [95% CI: 1.08-1.34] per 50% lower ferritin level) and higher risk for incident HFpEF (HR: 1.28 [95% CI: 1.09-1.50]). Associations with incident HFrEF were not statistically significant. Lower ferritin levels were associated with higher E/e' ratio and higher pulmonary artery systolic pressure after adjustment for demographics and HF risk factors but not with measures of left ventricular structure or systolic function.

CONCLUSIONS

Among older adults without prevalent HF or anemia, lower plasma ferritin level is associated with a higher risk for incident HF, HFpEF, and higher measures of left ventricular filling pressure.

Intracellular Regulation Limits the Response of Intestinal Ferroportin to Iron Status in Suckling Rats

SCOPE

Iron status is regulated via iron absorption as there is no active iron excretion. Divalent metal-ion transporter-1 (DMT1) and ferroportin (FPN) are two key proteins vital for iron absorption, but the regulation of them in suckling mammals differs from that in adults. This study aims to explore regulation of iron transporters under different iron conditions during suckling.

METHODS AND RESULTS

This study developed suckling rats under different iron conditions. Unexpectedly, unchanged FPN at different iron status are detected. Since FPN is the only known iron exporter for mammals, unchanged FPN limits iron exported into blood during suckling. Thus, factors regulating FPN at transcriptional, post-transcriptional, and post-translational levels are detected. Results showed that Fpn mRNA is upregulated, while micro RNA-485(miR-485) which could silence Fpn mRNA is upregulated at low iron status limiting translation of Fpn mRNA. Besides, serum hepcidin and liver Hamp mRNA are upregulated, but ring finger protein 217( Rnf217) mRNA remained unchanged at high iron status leading to FPN not downregulated as adults.

CONCLUSIONS

Overall, this study indicates that translational regulation limits intestinal FPN protein response to iron deficiency and Rnf217 cannot effectively mediate the degradation of FPN at high iron status, which provides a reference for maintaining iron homeostasis during suckling.

Iron deficiency anemia among women: An issue of health equity

Iron deficiency is the most common and widespread nutritional deficiency in the world. For women, the risk of iron deficiency and iron deficiency anemia increases due to iron demands during pregnancy and regular iron losses due to menstruation during reproductive years. These interrelated conditions are of public health concern as they are highly prevalent, and the negative consequences such as chronic fatigue, cognitive impairment and poor quality of life are broad and multifaceted. People of low socioeconomic status are at higher risk of iron deficiency due to low intake of expensive iron-rich foods, and decreased access to healthcare. In this review, we applied a health equity lens to describe the current state of care for women with iron deficiency with or without anemia. We have highlighted several structural challenges that span from the laboratory diagnosis, inconsistent screening guidelines, and stigma associated with heavy menstrual bleeding, to treatment barriers.

Role of mineral nutrients other than iron in pregnancy: under recognized opportunities to improve maternal/fetal outcomes: a literature review

BACKGROUND

Anemia during pregnancy is an important global health concern, affecting 40% of women worldwide, and iron deficiency shares a significant proportion of the burden. From conception to birth, pregnancy is a period when women undergo metabolic and physiological changes. The nutritional needs are higher during pregnancy; thus, adequate nutrition is essential to maintain fetal growth and development. However, adverse effects due to deficiency in nutrition during pregnancy can result in maternal, fetal and neonatal complications. Despite the multifactorial etiology of anemia, iron deficiency is assumed as the primary cause of anemia during pregnancy and hence, mitigation strategy pivots around it for anemia management. Therefore, excluding other contributors, a single-micronutrient approach with iron supplements remains a myopic approach and this can exacerbate iron deficiency anemia. Micronutrient deficiencies are of particular concern as they may pose a silent threat to the survival and well-being of reproductive-age women and their infants.

AIM

Micronutrients, especially trace minerals, play a myriad of roles in pregnancy, and the lack of each one causes adverse complications to both the mother and the fetus. In this review paper, we attempt to piece together available information regarding the adverse effects of abnormal trace mineral levels along with iron deficiency on the mother and the fetus.

METHOD

A non-systematic literature search in PubMed, Google Scholar, and the Cochrane databases, for publications on minerals and vitamins during pregnancy and the possible influence of supplements on pregnancy outcomes.

CONCLUSION

Micronutrient deficiency exacerbates the pregnancy-induced anemia and other adverse birth outcomes. Micronutrient supplementation during pregnancy can combat anemia as well as reduce a number of adverse pregnancy outcomes in a comprehensive manner.

Prognostic Performance of Hematological and Serum Iron and Metabolite Indices for Detection of Early Iron Deficiency Induced Metabolic Brain Dysfunction in Infant Rhesus Monkeys

BACKGROUND

The current pediatric practice of monitoring for infantile iron deficiency (ID) via hemoglobin (Hgb) screening at one y of age does not identify preanemic ID nor protect against later neurocognitive deficits.

OBJECTIVES

To identify biomarkers of iron-related metabolic alterations in the serum and brain and determine the sensitivity of conventional iron and heme indices for predicting risk of brain metabolic dysfunction using a nonhuman primate model of infantile ID.

METHODS

Simultaneous serum iron and RBC indices, and serum and cerebrospinal fluid (CSF) metabolomic profiles were determined in 20 rhesus infants, comparing iron sufficient (IS; N = 10) and ID (N = 10) infants at 2 and 4 mo of age.

RESULTS

Reticulocyte hemoglobin (RET-He) was lower at 2 wk in the ID group. Significant IS compared with ID differences in serum iron indices were present at 2 mo, but Hgb and RBC indices differed only at 4 mo (P < 0.05). Serum and CSF metabolomic profiles of the ID and IS groups differed at 2 and 4 mo (P < 0.05). Key metabolites, including homostachydrine and stachydrine (4-5-fold lower at 4 mo in ID group, P < 0.05), were altered in both serum and CSF. Iron indices and RET-He at 2 mo, but not Hgb or other RBC indices, were correlated with altered CSF metabolic profile at 4 mo and had comparable predictive accuracy (area under the receiver operating characteristic curve scores, 0.75-0.80).

CONCLUSIONS

Preanemic ID at 2 mo was associated with metabolic alterations in serum and CSF in infant monkeys. Among the RBC indices, only RET-He predicted the future risk of abnormal CSF metabolic profile with a predictive accuracy comparable to serum iron indices. The concordance of homostachydrine and stachydrine changes in serum and CSF indicates their potential use as early biomarkers of brain metabolic dysfunction in infantile ID.

Associations between anemia and FGF23 in the CKiD study

BACKGROUND

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that plays a central role in chronic kidney disease-mineral bone disorder and is associated with CKD progression and cardiovascular morbidity. Factors related to CKD-associated anemia, including iron deficiency, can increase FGF23 production. This study aimed to assess whether anemia and/or iron deficiency are associated with increased circulating concentrations of FGF23 in the large, well-characterized Chronic Kidney Disease in Children (CKiD) study cohort.

METHODS

Hemoglobin concentrations, iron parameters, C-terminal (total) FGF23, intact FGF23, and relevant covariables were measured in cross-sectional analysis of CKiD study subjects.

RESULTS

In 493 pediatric patients with CKD (median [interquartile range] age 13 [9, 16] years), the median estimated glomerular filtration rate was 48 [35, 61] ml/min/1.73 m2, and 103 patients (21%) were anemic. Anemic subjects had higher total FGF23 concentrations than non-anemic subjects (204 [124, 390] vs. 109 [77, 168] RU/ml, p < 0.001). In multivariable linear regression modeling, anemia was independently associated with higher total FGF23, after adjustment for demographic, kidney-related, mineral metabolism, and inflammatory covariables (standardized β (95% confidence interval) 0.10 (0.04, 0.17), p = 0.002). In the subset of subjects with available iron parameters (n = 191), iron deficiency was not associated with significantly higher total FGF23 concentrations. In the subgroup that had measurements of both total and intact FGF23 (n = 185), in fully adjusted models, anemia was significantly associated with higher total FGF23 (standardized β (95% CI) 0.16 (0.04, 0.27), p = 0.008) but not intact FGF23 (standardized β (95% CI) 0.02 (-0.12, 0.15), p = 0.81).

CONCLUSIONS

In this cohort of pediatric patients with CKD, anemia was associated with increased total FGF23 levels but was not independently associated with elevated intact FGF23, suggesting possible effects on both FGF23 production and cleavage. Further studies are warranted to investigate non-mineral factors affecting FGF23 production and metabolism in CKD.

Efficacy of Intravenous Iron in Patients with Heart Failure with Reduced Ejection Fraction and Iron Deficiency: A Systematic Review and Meta-Analysis of Randomized Control Trials

BACKGROUND

The European Society of Cardiology (ESC) provided a focused update to the 2021 Guideline for the Management of Heart Failure, now providing a 1A recommendation for intravenous iron in patients with heart failure with reduced ejection fraction (HFrEF) and iron deficiency (ID). However, the findings from randomized controlled trials (RCT) are mixed. This systematic review of RCTs aims to provide an update and synthesize the evidence addressing the association of intravenous iron with patient-based outcomes in patients with HFrEF and ID.

METHODS

Any RCT evaluating the effect of intravenous iron in patients with HFrEF and ID was eligible for inclusion. A complete search of the EMBASE and PubMed databases was conducted from inception until 15 September 2023. The primary outcome was the composite of the quality of life (QoL) questionnaires, while the secondary outcomes included first heart failure (HF) hospitalizations and all-cause mortality. Data extraction was performed independently by two reviewers. Data were pooled using a random-effects model.

RESULTS

Of the 1035 references, 15 RCTs enrolling 6649 patients were included in this study. Intravenous iron was associated with significant improvement in the composite of QoL (standardized mean difference - 1.36, 95% confidence interval [CI] - 2.24 to - 0.48; p = 0.002), a significant reduction in first HF hospitalizations (hazard ratio [HR] 0.73, 95% CI 0.56-0.95; p = 0.02), and with no change in all-cause mortality (HR 0.90, 95% CI 0.79-1.03; p = 0.12). The certainty of the evidence ranged from moderate to very low.

CONCLUSION

Intravenous iron is possibly associated with improved QoL and reduced HF hospitalizations, without impacting all-cause mortality. These findings not only support the use of intravenous iron in patients with HFrEF but also emphasize the need for well-designed and executed RCTs with granular outcome reporting and powered sufficiently to address the impact of intravenous iron on mortality in patients with HFrEF and ID.

REGISTRATION

PROSPERO identifier number CRD42023389.

Function of iron-stress-induced protein A in cyanobacterial cells with monomeric and trimeric photosystem I

The acclimation of cyanobacteria to iron deficiency is crucial for their survival in natural environments. In response to iron deficiency, many cyanobacterial species induce the production of a pigment-protein complex called iron-stress-induced protein A (IsiA). IsiA proteins associate with photosystem I (PSI) and can function as light-harvesting antennas or dissipate excess energy. They may also serve as chlorophyll storage during iron limitation. In this study, we examined the functional role of IsiA in cells of Synechocystis sp. PCC 6803 grown under iron limitation conditions by measuring the cellular IsiA content and its capability to transfer energy to PSI. We specifically tested the effect of the oligomeric state of PSI by comparing wild-type (WT) Synechocystis sp. PCC 6803 with mutants lacking specific subunits of PSI, namely PsaL/PsaI (PSI subunits XI/VIII) and PsaF/PsaJ (PSI subunits III/IX). Time-resolved fluorescence spectroscopy revealed that IsiA formed functional PSI3-IsiA18 supercomplexes, wherein IsiA effectively transfers energy to PSI on a timescale of 10 ps at room temperature-measured in isolated complexes and in vivo-confirming the primary role of IsiA as an accessory light-harvesting antenna to PSI. However, a notable fraction (40%) remained unconnected to PSI, supporting the notion of a dual functional role of IsiA. Cells with monomeric PSI under iron deficiency contained, on average, only 3 to 4 IsiA complexes bound to PSI. These results show that IsiA can transfer energy to trimeric and monomeric PSI but to varying degrees and that the acclimatory production of IsiA under iron stress is controlled by its ability to perform its light-harvesting function.

Prevalence and correlates of childhood anemia in the MINA-Brazil birth cohort study

OBJECTIVE

This study aimed to describe the prevalence and predictors of childhood anemia in an Amazonian population-based birth cohort study.

METHODS

Prevalence of maternal anemia was estimated at delivery (hemoglobin [Hb] concentration < 110 g/L) in women participating in the MINA-Brazil birth cohort study and in their children, examined at ages one, two (Hb < 110 g/L), and five (Hb < 115 g/L). Moreover, ferritin, soluble transferrin receptor, and C-reactive protein concentrations were measured in mothers at delivery and in their 1- and 2-year-old children to estimate the prevalence of iron deficiency and its contribution to anemia, while adjusting for potential confounders by multiple Poisson regression analysis (adjusted relative risk [RRa]).

RESULTS

The prevalence 95% confidence interval (CI) of maternal anemia, iron deficiency, and iron-deficiency anemia at delivery were 17.3% (14.0-21.0%), 42.6% (38.0-47.2%), and 8.7% (6.3-11.6)%, respectively (n = 462). At one year of age (n = 646), 42.2% (38.7-45.8%) of the study children were anemic, 38.4% (34.6-42.3%) were iron-deficient, and 26.3 (23.0-29.9) had iron-deficiency anemia. At two years of age (n = 761), these values decreased to 12.8% (10.6-15.2%), 18.1% (15.5-21.1%), and 4.1% (2.8-5.7%), respectively; at five years of age (n = 655), 5.2% (3.6-7.2%) were anemic. Iron deficiency (RRa = 2.19; 95%CI: 1.84-2.60) and consumption of ultra-processed foods (UPF) (RRa = 1.56; 95%CI: 1.14-2.13) were significant contributors to anemia at 1 year, after adjusting for maternal schooling. At 2 years, anemia was significantly associated with maternal anemia at delivery (RRa: 1.67; 95%CI: 1.17-2.39), malaria since birth (2.25; 1.30-3.87), and iron deficiency (2.15; 1.47-3.15), after adjusting for children's age and household wealth index.

CONCLUSIONS

Anemia continues to be highly prevalent during pregnancy and early childhood in the Amazon. Public health policies should address iron deficiency, UPF intake, maternal anemia, and malaria to prevent and treat anemia in Amazonian children.

Increasing rates of screening and treatment of iron deficiency in ambulatory patients with heart failure with reduced ejection fraction: a quality improvement cohort study

INTRODUCTION

Iron deficiency anaemia (IDA) is common in patients with heart failure (HF) and is associated with advanced HF and increased mortality. Intravenous iron supplementation increases exercise tolerance, improves quality of life, and decreases symptoms among patients with HF with reduced ejection fraction (HFrEF) and iron deficiency. Despite this, many patients are not screened or treated for IDA. We aimed to increase rates of screening and treatment of IDA among HF patients through the introduction of curated materials to aid HF clinicians with appropriate screening and treatment.

METHODS

We conducted a retrospective chart review to identify the baseline number of HFrEF patients screened and treated for IDA at two ambulatory cardiology clinics in Toronto, Ontario. A quality improvement initiative was then introduced, which consisted of education and curated materials to aid clinicians in the screening and treatment of IDA among HFrEF patients. The proportion of patients screened and treated for IDA preintervention and postintervention were compared using χ2 tests of Independence.

RESULTS

In the preintervention cohort, 36.3% (n=45) of patients with anaemia were screened for IDA. Among those screened, 64.4% (n=29) had IDA. Only 17.2% (n=5) of these were treated with IV iron. After implementation of the quality improvement initiative, 90.9% (n=60) of patients with anaemia were screened for IDA (p<0.001) and 90.3% (n=28) of those with IDA were treated with IV iron (p<0.001).

CONCLUSION

The introduction of curated materials to aid clinicians was associated with increased rates of screening and treatment of IDA among ambulatory HFrEF patients. Further work is required to identify barriers and implement strategies to increase screening and treatment rates of IDA among HFrEF patients.

The magnitude of the plasma hepcidin response to oral iron supplements depends on the iron dosage

BACKGROUND

Iron deficiency without anaemia is a common health problem, especially in young menstruating women. The efficacy of the usually recommended oral iron supplementation is limited due to increased plasma hepcidin concentration, which reduces iron absorption and leads to side effects such as intestinal irritation. This observation raises the question of how low-dose iron therapy may affect plasma hepcidin levels and whether oral iron intake dose-dependently affects plasma hepcidin production.

METHODS

Fifteen non-anaemic women with iron deficiency (serum ferritin ≤30 ng/ml) received a single dose of 0, 6, 30, or 60 mg of elemental oral iron as ferrous sulfate on different days. Plasma hepcidin was measured before and seven hours after each dose.

RESULTS

Subjects had an average age of 23 (standard deviation = 3.0) years and serum ferritin of 24 ng/ml (interquartile range = 16-27). The highest mean change in plasma hepcidin levels was measured after ingesting 60 mg of iron, increasing from 2.1 ng/ml (interquartile range = 1.6-2.9) to 4.1 ng/ml (interquartile range = 2.5-6.9; p < 0.001). Iron had a significant dose-dependent effect on the absolute change in plasma hepcidin (p = 0.008), where lower iron dose supplementation resulted in lower plasma hepcidin levels. Serum ferritin levels were significantly correlated with fasting plasma hepcidin levels (R2 = 0.504, p = 0.003) and the change in plasma hepcidin concentration after iron intake (R2 = 0.529, p = 0.002).

CONCLUSION

We found a dose-dependent effect of iron supplementation on plasma hepcidin levels. Lower iron dosage results in a smaller increase in hepcidin and might thus lead to more efficient intestinal iron absorption and fewer side effects. The effectiveness and side effects of low-dose iron treatment in women with iron deficiency should be further investigated. This study was registered at the Swiss National Clinical Trials Portal (2021-00312) and ClinicalTrials.gov (NCT04735848).

Cross-country health inequalities of four common nutritional deficiencies among children, 1990 to 2019: data from the Global Burden of Disease Study 2019

BACKGROUND

Nutritional deficiencies remain serious medical and public health issues worldwide, especially in children. This study aims to analyze cross-country inequality in four common nutritional deficiencies (protein-energy malnutrition, dietary iron deficiency, vitamin A deficiency and iodine deficiency) among children from 1990 to 2019 based on Global Burden of Disease (GBD) 2019 data.

METHODS

Prevalence and disability-adjusted life years (DALYs) data as measures of four nutritional deficiency burdens in people aged 0 to 14 years were extracted from the GBD Results Tool. We analyzed temporal trends in prevalence by calculating the average annual percent change (AAPC) and quantified cross-country inequalities in disease burden using the slope index.

RESULTS

Globally, the age-standardized prevalence rates of dietary iron deficiency, vitamin A deficiency and iodine deficiency decreased, with AAPCs of -0.14 (-0.15 to -0.12), -2.77 (-2.96 to -2.58), and -2.17 (-2.3 to -2.03) from 1999 to 2019, respectively. Significant reductions in socio-demographic index (SDI)-related inequality occurred in protein-energy malnutrition and vitamin A deficiency, while the health inequality for dietary iron deficiency and iodine deficiency remained basically unchanged. The age-standardized prevalence and DALY rates of the four nutritional deficiencies decreased as the SDI and healthcare access and quality index increased.

CONCLUSIONS

The global burden of nutritional deficiency has decreased since 1990, but cross-country health inequalities still exist. More efficient public health measures are needed to reduce disease burdens, particularly in low-SDI countries/territories.

Serum ferritin/C-reactive protein ratio is a simple and effective biomarker for diagnosing iron deficiency in the context of systemic inflammation

BACKGROUND

Diagnosing iron deficiency is challenging in the presence of systemic inflammation.

AIM

To investigate the relationship between plasma C-reactive protein (CRP), serum ferritin (SF) and transferrin saturation (TS), with the objective of establishing a straightforward ratio applicable in the presence of inflammatory syndrome.

DESIGN

Test prospective cohort and validation retrospective cohort.

METHODS

A prospective cohort of inpatients (n = 140) assessed the correlation between CRP and SF/TS levels. The diagnostic performance of a determined ratio was evaluated for identifying iron deficiency (ID) using different definitions and in the presence of inflammation and/or chronic heart and/or kidney failure. A large validation cohort (n = 795) further assessed the predictive power of this ratio.

RESULTS

In a training cohort (median age 76 years [57-84]), a linear relation was observed between SF (µg/l) and CRP (mg/l), unlike with TS. The SF/CRP ratio accurately predicted ID, with receiver operating characteristic-area under the curve (ROC-AUC) values ranging from 0.85 to 0.92 for different ID definitions. A threshold of ≤6 demonstrated the highest Youden index (0.61). In the validation cohort (age 72 years [57-84]), the SF/CRP ratio exhibited an ROC-AUC of 0.88 [95% CI: 0.85-0.90], with an odds ratio of 37.9 [95% CI: 20.3-68.9] for the threshold of ≤6.

CONCLUSION

In this study, we demonstrated that the SF/CRP ratio, with a threshold of ≤6, is a simple and effective biomarker for ID, even in the presence of systemic inflammation or comorbidities. This ratio could potentially replace the complex set of criteria currently recommended by learned societies.

Iron deficiency anemia: a critical review on iron absorption, supplementation and its influence on gut microbiota

Iron deficiency anemia (IDA) caused by micronutrient iron deficiency has attracted global attention due to its adverse health effects. The regulation of iron uptake and metabolism is finely controlled by various transporters and hormones in the body. Dietary iron intake and regulation are essential in maintaining human health and iron requirements. The review aims to investigate literature concerning dietary iron intake and systemic regulation. Besides, recent IDA treatment and dietary iron supplementation are discussed. Considering the importance of the gut microbiome, the interaction between bacteria and micronutrient iron in the gut is also a focus of this review. The iron absorption efficiency varies considerably according to iron type and dietary factors. Iron fortification remains the cost-effective strategy, although challenges exist in developing suitable iron fortificants and food vehicles regarding bioavailability and acceptability. Iron deficiency may alter the microbiome structure and promote the growth of pathogenic bacteria in the gut, affecting immune balance and human health.

Iron Deficiency and Vitamin D Deficiency Are Associated with Sleep in Females of Reproductive Age: An Analysis of NHANES 2005-2018 Data

BACKGROUND

Iron and vitamin D deficiencies have been implicated in sleep disturbance. Although females are more susceptible to these deficiencies and frequently report sleep-related issues, few studies have examined these associations in females.

OBJECTIVE

This study investigates the association of iron and vitamin D deficiencies on sleep in a nationally representative sample of females of reproductive age.

METHODS

We used 2 samples of 20-49-y-old non-pregnant females from National Health and Nutrition Examination Survey (NHANES) 2005-2008 (N = 2497) and NHANES 2005-2010 and 2015-2018 (N = 6731) to examine the associations of iron deficiency (ID), iron deficiency anemia (IDA), vitamin D deficiency (VDD), vitamin D inadequacy (VDI), and the joint association of both deficiencies with sleep duration, latency, and quality. Sleep outcomes were measured using a self-reported questionnaire. We used the body iron model based on serum ferritin and serum soluble transferrin receptor to identify ID, along with hemoglobin to identify IDA cases. In addition, 25-hydroxyvitamin D levels were used to determine VDD and VDI cases. Logistic regression was used to evaluate these associations, adjusting for potential confounders. In addition, we assessed the multiplicative and additive interactions of both deficiencies.

RESULTS

ID and IDA were associated with poor sleep quality, with 1.42 [95% confidence interval (CI): 1.02, 2.00)] and 2.08 (95% CI: 1.29, 3.38) higher odds, respectively, whereas VDD and VDI were significantly associated with short sleep duration, with 1.26 (95% CI: 1.02, 1.54) and 1.22 (95% CI: 1.04, 1.44) higher odds, respectively. Subjects with both nutritional deficiencies had significantly higher odds of poorer sleep quality compared with subjects with neither condition. For sleep quality, a significant multiplicative interaction was observed between ID and VDD (P value = 0.0005). No associations were observed between study exposures and sleep latency.

CONCLUSIONS

Among females of reproductive age, iron and vitamin D deficiencies are associated with sleep health outcomes. The potential synergistic effect of both deficiencies warrants further assessment.

Relationship between serum iron level and physical function in heart failure patients is lost by presence of diabetes

AIMS

Iron deficiency (ID) is common in patients with heart failure (HF) and is reportedly associated with exercise intolerance and impaired quality of life. Iron supplementation therapy in HF patients with ID improves exercise capacity. Conversely, protective roles of iron depletion in the development of diabetes mellitus (DM) and its complications have been proposed. This study aimed to determine the impact of ID on physical function in HF patients with and without DM.

METHODS AND RESULTS

We enrolled consecutive patients who were admitted to our institute for HF diagnosis and management. The short physical performance battery (SPPB) was used to evaluate physical function, and low physical function was defined as an SPPB score of <10 points as individuals with SPPB scores of <10 points are most likely to be classified as frail and are at high risk for disability and future adverse events, including death. ID was defined as serum ferritin < 100 or 100-299 ng/mL when transferrin saturation (TSAT) was <20% according to the HF guidelines. Among the 562 HF patients (72 ± 14 years old; 56% male), 329 patients (58%) and 191 patients (34%) had ID and low physical function, respectively. Multivariate logistic regression analysis showed that TSAT as a continuous variable, but not ID, was a predictor of low physical function (odds ratio: 0.980, P = 0.024). Subgroup analysis showed that a significant association between low TSAT and low physical function was lost in HF patients with DM (P for interaction < 0.001). A spline dose-response curve for the relationship between TSAT and risk of low physical function with adjustments for covariates associated with low physical function in non-DM patients was almost linear with an increase in the risk of low physical function as the TSAT increased, but such a relationship was not found in the analyses of DM patients. A lack of close TSAT-SPPB relationship in HF patients with DM was confirmed also in a propensity-score-matched cohort.

CONCLUSIONS

TSAT as a continuous variable, but not ID, was independently associated with physical function in HF patients, and a significant association was lost in patients with HF and DM, suggesting a limited impact of iron supplementation therapy in HF patients with DM.

The correlation between Helicobacter pylori infection and iron deficiency anemia in women

OBJECTIVE

In recent years, Helicobacter pylori (H. pylori) has been increasingly associated with extra-digestive manifestations, including scleroderma, rheumatism, and blood system diseases. Iron deficiency anemia (IDA) is a common chronic disease worldwide, with an insidious onset, but as the disease progresses, it will eventually seriously affect the quality of life of patients. The aim of our study was to investigate the relationship between H. pylori infection, iron deficiency (ID), and IDA, and to identify potential serological markers.

PATIENTS AND METHODS

We conducted a cross-sectional study of 998 individuals who had regular physical examinations at Beijing Shijitan Hospital from January 2021 to March 2022. We detected H. pylori infection by the 13C breath test, and recorded the patient's serum iron, ferritin, transferrin saturation, blood count, etc. We assessed the association between IDA and H. pylori infection and related serum markers using logistic regression and multiple linear regression. Afterward, we analyzed the correlation between sex and potential serum biomarkers.

RESULTS

Among all study participants, 57.5% of patients had H. pylori and 42.5% did not have H. pylori. ID and IDA were significantly associated with H. pylori infection in women (p=0.031). This association persisted after further adjustment for sex, metabolic variables, liver function, and kidney function. Fasting blood glucose, triglycerides, and uric acid may be associated with IDA.

CONCLUSIONS

In women, H. pylori infection is associated with ID and IDA. The relationship between H. pylori and IDA may be mediated by glycometabolism, lipid metabolism, and uric acid metabolism.

Transcriptome and biochemical analysis in hexaploid wheat with contrasting tolerance to iron deficiency pinpoints multi-layered molecular process

Iron (Fe) is an essential plant nutrient that is indispensable for many physiological activities. This study is an effort to identify the molecular and biochemical basis of wheat genotypes with contrasting tolerance towards Fe deficiency. Our physiological experiments performed at the early growth stage in cv. Kanchan (KAN) showed Fe deficiency tolerance, whereas cv. PBW343 (PBW) was susceptible. Under Fe deficient condition, KAN showed delayed chlorosis, high SPAD values, and low malondialdehyde content compared to PBW, indicative of Fe deficient condition. Comparative shoot transcriptomics revealed increased expression of photosynthetic pathway genes in PBW, further suggesting its sensitivity to Fe fluctuations. Under Fe deficiency, both the cultivars showed distinct molecular re-arrangements such as high expression of genes involved in Fe uptake (including membrane transporters) and its remobilization. Specifically, in KAN these changes lead to high root phytosiderophores (PS) biosynthesis and its release, resulting in enhanced Fe translocation index. Utilizing the non-transgenic TILLING (Targeting Induced Lesions in Genomes) technology, we identified TaZIFL4.2D as a putative PS efflux transporter. Characterization of the wheat TILLING lines indicated that TaZIFL4.2 functions in PS release and Fe acquisition, thereby imparting tolerance to Fe deficiency. Altogether, this work highlights the mechanistic insight into Fe deficiency tolerance of hexaploid wheat, thus enabling breeders to select suitable genotypes to utilize nutrients for maximum yields.

Clinical outcomes of intravenous iron therapy in patients with heart failure and iron deficiency: Meta-analysis and trial sequential analysis of randomized clinical trials

BACKGROUND

Iron deficiency in patients with heart failure (HF) is underdiagnosed and undertreated. The role of intravenous (IV) iron is well-established to improve quality of life measures. Emerging evidence also supports its role in preventing cardiovascular events in patients with HF.

METHODOLOGY

We conducted a literature search of multiple electronic databases. Randomized controlled trials that compared IV iron to usual care among patients with HF and reported cardiovascular (CV) outcomes were included. Primary outcome was the composite of first heart failure hospitalization (HFH) or CV death. Secondary outcomes included HFH (first or recurrent), CV death, all-cause mortality, hospitalization for any cause, gastrointestinal (GI) side effects, or any infection. We performed trial sequential and cumulative meta-analyses to evaluate the effect of IV iron on the primary endpoint, and on HFH.

RESULTS

Nine trials enrolling 3337 patients were included. Adding IV iron to usual care significantly reduced the risk of first HFH or CV death [risk ratio (RR) 0.84; 95 % confidence interval (CI) 0.75-0.93; I2 = 0 %; number needed to treat (NNT) 18], which was primarily driven by a reduction in the risk of HFH of 25 %. IV iron also reduced the risk of the composite of hospitalization for any cause or death (RR 0.92; 95 % CI 0.85-0.99; I2 = 0 %; NNT 19). There was no significant difference in the risk of CV death, all-cause mortality, adverse GI events, or any infection among patients receiving IV iron compared to usual care. The observed benefits of IV iron were directionally consistent across trials and crossed both the statistical and trial sequential boundaries of benefit.

CONCLUSION

In patients with HF and iron deficiency, the addition of IV iron to usual care reduces the risk of HFH without affecting the risk of CV or all-cause mortality.

Sevoflurane causes cognitive impairment by inducing iron deficiency and inhibiting the proliferation of neural precursor cells in infant mice

AIMS

Numerous studies on animals have shown that exposure to general anesthetics in infant stage may cause neurocognitive impairment. However, the exact mechanism is not clear. The dysfunction of iron metabolism can cause neurodevelopmental disorders. Therefore, we investigated the effect of iron metabolism disorder induced by sevoflurane (Sev) on cognitive function and the proliferation of neural precursor cells (NPCs) and neural stem cells (NSCs) in infant mice.

METHODS

C57BL/6 mice of postnatal day 14 and neural stem cells NE4C were treated with 2% Sev for 6 h. We used the Morris water maze (MWM) to test the cognitive function of infant mice. The proliferation of NPCs was measured using bromodeoxyuridine (BrdU) label and their markers Ki67 and Pax6 in infant brain tissues 12 h after anesthesia. Meanwhile, we used immunohistochemical stain, immunofluorescence assay, western blot, and flow cytometer to evaluate the myelinogenesis, iron levels, and cell proliferation in cortex and hippocampus or in NE4C cells.

RESULTS

The results showed that Sev significantly caused cognitive deficiency in infant mice. Further, we found that Sev inhibited oligodendrocytes proliferation and myelinogenesis by decreasing MBP and CC-1 expression and iron levels. Meanwhile, Sev also induced the iron deficiency in neurons and NSCs by downregulating FtH and FtL expression and upregulating the TfR1 expression in the cortex and hippocampus, which dramatically suppressed the proliferation of NSCs and NPCs as indicated by decreasing the colocalization of Pax6+ and BrdU+ cells, and caused the decrease in the number of neurons. Interestingly, iron supplementation before anesthesia significantly improved iron deficiency in cortex and hippocampus and cognitive deficiency induced by Sev in infant mice. Iron therapy inhibited the decrease of MBP expression, iron levels in neurons and oligodendrocytes, and DNA synthesis of Pax6+ cells in hippocampus induced by Sev. Meanwhile, the number of neurons was partially recovered in hippocampus.

CONCLUSION

The results from the present study demonstrated that Sev-induced iron deficiency might be a new mechanism of cognitive impairment caused by inhaled anesthetics in infant mice. Iron supplementation before anesthesia is an effective strategy to prevent cognitive impairment caused by Sev in infants.

A microalgae docosahexaenoic acid supplement does not modify the influence of sex and diet on iron status in Spanish vegetarians or omnivores: A randomized placebo-controlled crossover study

OBJECTIVE

Plant-based diets are accepted as healthy, provided that are well-planned and include supplements. In this context, iron deficiency is a threat, and data from Spanish vegetarians are scarce. The aim of this study was to determine if a microalgae ω-3 supplement rich in docosahexaenoic acid (DHA) affected iron status in this population.

METHODS

Iron biomarkers and nutrient intake (72-h dietary records) were analyzed in 204 usual consumers of lacto-ovo vegetarian (LOV), vegan (VEG), or omnivorous (OMN) diets. A randomized double-blind, placebo-controlled crossover trial was performed in a subgroup (n = 98) to test if a microalgae DHA supplement (250 mg/d for 5 wk) changed iron status.

RESULTS

Iron intake was higher in vegetarians than omnivores (P= 0.002), fiber intake was highest in vegans followed by lacto-ovo vegetarians and omnivores, whereas calcium intake was lower in vegans than both lacto-ovo vegetarians and omnivores (all P < 0.001). Women, regardless of diet type, showed lower iron status than men. Erythrocytes, hemoglobin, hematocrit, and serum ferritin were lower in lacto-ovo vegetarians and vegans than omnivores. The prevalence of iron deficiency anemia was low (<10%), but iron depletion (ferritin <15 ng/mL) was higher in lacto-ovo vegetarians than omnivores (P = 0.003). Iron biomarkers were similar in lacto-ovo vegetarians and vegans. The DHA supplementation did not change iron status compared with placebo.

CONCLUSIONS

Spanish vegetarians had lower iron status than omnivores. Consumption of eggs and dairy products increased the risk for iron deficiency, but a microalgae DHA supplement had no effect. Dietary strategies to increase iron bioavailability in vegetarians, particularly in lacto-ovo vegetarians and women, are recommended.