scholarly journals Effect of calcium intake on iron absorption and hematologic status: A systematic review and dose-response meta-analysis of randomized trials and case-cross-over studies

2020 ◽  
Author(s):  
Ajibola I Abioye ◽  
Taofik A Okuneye ◽  
Abdul Majeed O Odesanya ◽  
Olufunmilola Adisa ◽  
Asanat I Abioye ◽  
...  
Keyword(s):  
Serum Ferritin ◽  
Dose Response ◽  
Calcium Intake ◽  
Iron Absorption ◽  
Iron Status ◽  
Detailed Knowledge ◽  
Clinical Effects ◽  
Ferritin Concentration ◽  
Intermediate Outcomes ◽  
Serum Ferritin Concentration

Background: The interaction between dietary (and supplementary) divalent ions has been a long-standing issue in human nutrition research. Developing optimal calcium and iron supplementation recommendation needs detailed knowledge of the potential trade-offs between: a) the clinical effects of concurrent intake on iron absorption and hematological indices, and b) the potentially negative effects of separated ingestion on adherence to either or both iron and calcium supplements. Human clinical studies have examined the effects of calcium intake on iron status, but there are no meta-analyses or recent reviews summarizing the findings. Objective: We aimed to summarize the literature on the effect of calcium consumption from meals and supplements on iron indices in humans, and quantify the pooled effects. Design: Peer-reviewed randomized and case-cross-over studies were included in this review. Result: The negative effect of calcium intake was statistically significant in short-term iron absorption studies but the effect magnitude was low (weighted mean difference (WMD) = -5.57%, (95% CI: -7.09, -4.04)). The effect of calcium on iron status was mixed. There was a quadratic dose-response relationship between calcium intake and serum ferritin concentration. Higher daily calcium intake was associated with a modest reduction in serum ferritin concentration. There was, however, no reduction in hemoglobin concentration (WMD = 1.22g/L, 95% CI: 0.37, 2.07). Conclusion: The existing body of studies is insufficient to make recommendations with high confidence due to heterogeneity in design, limitations of ferritin as an iron biomarker and lack of intake studies in pregnant women. Prescribing separation of prenatal calcium and iron supplements in free living individuals is unlikely to affect the anemia burden. There is a need for effectiveness trials comparing the effects of prescribing separated intake to concurrent intake, with functional end-points as primary outcomes, and adherence to each supplement as intermediate outcomes.

Food iron absorption in idiopathic hemochromatosis

Blood ◽  
1989 ◽  
Vol 74 (6) ◽  
pp. 2187-2193 ◽  
Author(s):  
SR Lynch ◽  
BS Skikne ◽  
JD Cook
Keyword(s):  
Serum Ferritin ◽  
Iron Absorption ◽  
Iron Status ◽  
Normal Subjects ◽  
Heme Iron ◽  
Nonheme Iron ◽  
Ferritin Concentration ◽  
Normal Volunteers ◽  
Idiopathic Hemochromatosis ◽  
The Relationship

Abstract The relationship between iron status and food iron absorption was evaluated in 75 normal volunteers, 15 patients with idiopathic hemochromatosis, and 22 heterozygotes by using double extrinsic radioiron tags to label independently the nonheme and heme iron components of a hamburger meal. In normal subjects, absorption from each of these pools was inversely correlated with storage iron, as measured by the serum ferritin concentration. In patients with hemochromatosis, absorption of both forms of iron was far greater than would be predicted from the relationship between absorption and serum ferritin observed in normal volunteers. Nevertheless, there was still a modest but statistically significant reduction in absorption of nonheme iron with increasing serum ferritin. This relationship could not be demonstrated in the case of heme iron absorption. In heterozygotes, nonheme iron absorption from a hamburger meal containing no supplementary iron did not differ significantly from that observed in normal volunteers. However, when this meal was both modified to promote bioavailability and supplemented with iron, absorption of nonheme iron was significantly elevated. These studies confirm the presence of excessive nonheme iron absorption even from unfortified meals in patients with idiopathic hemochromatosis and suggest in addition that they are particularly susceptible to iron loading from diets containing a high proportion of heme iron. Impaired regulation of nonheme iron absorption was also observed in heterozygous individuals, but a statistically significant abnormality was demonstrable only when the test meal contained a large highly bioavailable iron supplement.

Hepatic computed tomography for monitoring the iron status of haemodialysis patients with haemosiderosis treated with recombinant human erythropoietin

1991 ◽  
Vol 81 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Sergio De Marchi ◽  
Emanuela Cecchin
Keyword(s):  
Computed Tomography ◽  
Serum Ferritin ◽  
Recombinant Human Erythropoietin ◽  
Chelation Therapy ◽  
Iron Status ◽  
Transferrin Saturation ◽  
Ferritin Concentration ◽  
Human Erythropoietin ◽  
Serum Ferritin Concentration ◽  
Erythropoietin Treatment

1. A randomized, partial-crossover study was conducted in uraemic patients with dialysis-associated anaemia and transfusional iron overload to evaluate the effects of desferrioxamine chelation therapy and of recombinant human erythropoietin treatment on hepatic iron storage determined by computed tomography, as well as by serum ferritin concentration and transferrin saturation. 2. Twenty-one haemodialysis patients with moderate iron overload, confirmed by values of serum ferritin concentration, transferrin saturation and hepatic computed tomography density exceeding 1000 μg/l, 45% and 68 Hounsfield units respectively, were randomly allocated to three groups and were followed for 12 months. 3. During the first 6 months group 1 (n = 7) received desferrioxamine chelation therapy (30 mg/kg intravenously three times a week) and group 2 (n = 7) underwent recombinant human erythropoietin treatment (36 units/kg intravenously three times a week). Thereafter, in the second 6 months of observation patients in group 1 were switched to receive recombinant human erythropoietin. Because of a poor response in the desferrioxaminetreated group in the initial 6 months, patients in group 2 continued on the maintenance dose of recombinant human erythropoietin (18 units/kg three times a week) until the end of the trial. Patients in group 3 (n = 7) were maintained on placebo throughout the study. 4. In comparison with placebo, recombinant human erythropoietin treatment, but not desferrioxamine chelation therapy, reduced serum ferritin concentration, transferrin saturation and hepatic computed tomography density, and was associated with a rise in haemoglobin and packed cell volume. Hepatic computed tomography density, serum ferritin concentration and transferrin saturation decreased in 13 out of 14 patients (93%) during treatment with recombinant human erythropoietin. However, when the changes in hepatic computed tomography density were compared with those in the biochemical indices, we observed that the decreases in serum ferritin concentration and transferrin saturation were much slower and delayed. More specifically, within 6 months of starting recombinant human erythropoietin treatment, hepatic computed tomography density was normalized in 13 out of 14 patients (93%), whereas serum ferritin concentration and transferrin saturation were within the normal limits in only two (14%) and six patients (43%), respectively. 5. In conclusion, the strategies for monitoring the iron status of haemodialysis patients with transfusional haemosiderosis may evolve to a new level of sophistication with the introduction of computed tomography scanning. This technique has the advantage of estimating directly the effect of recombinant human erythropoietin treatment on hepatic iron storage. Hepatic computed tomography density is complementary to serum ferritin concentration and transferrin saturation in monitoring the iron status of haemodialysis patients treated with recombinant human erythropoietin.

Relationships among Iron Absorption, Percent Saturation of Plasma Transferrin and Serum Ferritin Concentration in Humans

1988 ◽  
Vol 118 (9) ◽  
pp. 1110-1115 ◽  
Author(s):  
Peter Taylor ◽  
Carlos Martínez-Torres ◽  
Irene Leets ◽  
José Ramírez ◽  
María Nieves García-Casal ◽  
...  
Keyword(s):  
Serum Ferritin ◽  
Iron Absorption ◽  
Ferritin Concentration ◽  
Serum Ferritin Concentration

scholarly journals Food iron absorption in idiopathic hemochromatosis

Blood ◽  
1989 ◽  
Vol 74 (6) ◽  
pp. 2187-2193 ◽  
Author(s):  
SR Lynch ◽  
BS Skikne ◽  
JD Cook
Keyword(s):  
Serum Ferritin ◽  
Iron Absorption ◽  
Iron Status ◽  
Normal Subjects ◽  
Heme Iron ◽  
Nonheme Iron ◽  
Ferritin Concentration ◽  
Normal Volunteers ◽  
Idiopathic Hemochromatosis ◽  
The Relationship

The relationship between iron status and food iron absorption was evaluated in 75 normal volunteers, 15 patients with idiopathic hemochromatosis, and 22 heterozygotes by using double extrinsic radioiron tags to label independently the nonheme and heme iron components of a hamburger meal. In normal subjects, absorption from each of these pools was inversely correlated with storage iron, as measured by the serum ferritin concentration. In patients with hemochromatosis, absorption of both forms of iron was far greater than would be predicted from the relationship between absorption and serum ferritin observed in normal volunteers. Nevertheless, there was still a modest but statistically significant reduction in absorption of nonheme iron with increasing serum ferritin. This relationship could not be demonstrated in the case of heme iron absorption. In heterozygotes, nonheme iron absorption from a hamburger meal containing no supplementary iron did not differ significantly from that observed in normal volunteers. However, when this meal was both modified to promote bioavailability and supplemented with iron, absorption of nonheme iron was significantly elevated. These studies confirm the presence of excessive nonheme iron absorption even from unfortified meals in patients with idiopathic hemochromatosis and suggest in addition that they are particularly susceptible to iron loading from diets containing a high proportion of heme iron. Impaired regulation of nonheme iron absorption was also observed in heterozygous individuals, but a statistically significant abnormality was demonstrable only when the test meal contained a large highly bioavailable iron supplement.

scholarly journals The determinants of iron status in early pregnancy

1998 ◽  
Vol 79 (3) ◽  
pp. 249-255 ◽  
Author(s):  
Siân Robinson ◽  
Keith Godfrey ◽  
Jonathan Denne ◽  
Vanessa Cox
Keyword(s):  
Cell Volume ◽  
Serum Ferritin ◽  
Early Pregnancy ◽  
Iron Status ◽  
Population Sample ◽  
Haemoglobin Concentration ◽  
Mean Cell Volume ◽  
Ferritin Concentration ◽  
Serum Ferritin Concentration ◽  
Multiparous Women

In pregnancy, the additional demands for Fe are thought to be met principally through increased maternal dietary Fe absorption and by mobilization of maternal Fe stores. In a general population sample of 576 women we examined the maternal and dietary characteristics which influenced Fe stores (assessed by serum ferritin concentration) in early pregnancy. The effects of these characteristics on two measures of functional Fe status (mean cell volume and haemoglobin concentration) were also considered. Serum ferritin concentrations were lower in multiparous women (P < 0.0001) and in those with a lower BMI (P = 0.01), and rose with increasing alcohol intake (P < 0.0001). Ferritin concentrations fell with increasing Ca intake (P < 0.0001); the proportion of women with serum ferritin values ≤ 12 μg/l rose from 14% of the women in the lowest quarter of Ca intake to 29% of the women in the highest quarter. Mean cell volume and haemoglobin concentration were not related to Ca intake in early pregnancy. Although Ca added to test-meals reduces Fe absorption, long-term Ca supplementation has not been shown to lower plasma ferritin concentration, suggesting that high habitual Ca intakes would be unlikely to influence Fe status in non-pregnant individuals. Our findings show that in early pregnancy there is an association between high dietary Ca intake and lower Fe stores. This effect of Ca on one aspect of Fe status may result from its influence on Fe bioavailability.

Influence of gestational age and fetal iron status on IRP activity and iron transporter protein expression in third-trimester human placenta

2004 ◽  
Vol 287 (4) ◽  
pp. R894-R901 ◽  
Author(s):  
Jenni Bradley ◽  
Elizabeth A. Leibold ◽  
Z. Leah Harris ◽  
Jane D. Wobken ◽  
Stephen Clarke ◽  
...  
Keyword(s):  
Protein Expression ◽  
Serum Ferritin ◽  
Gestational Age ◽  
Iron Transport ◽  
Iron Status ◽  
Binding Activity ◽  
Third Trimester ◽  
Ferritin Concentration ◽  
Transporter Protein ◽  
Serum Ferritin Concentration

Placental iron transport during the last trimester of pregnancy determines the iron endowment of the neonate. Iron transport is a function of the major iron transport proteins: transferrin receptor-1 (TfR-1) and ferroportin-1 (FPN-1). The mRNAs for TfR-1 and, potentially, FPN-1 are posttranscriptionally regulated by iron regulatory protein (IRP)-1 and IRP-2. We assessed the effect of gestational age and fetal iron status on IRP-1- and IRP-2-binding activity and on the localization and protein expression of TfR-1 and FPN-1 protein at 24–40 wk of gestation in 21 placentas obtained from iron-sufficient nonanemic mothers. Gestational age had no effect on cord serum ferritin concentration, IRP-2 RNA-binding activity, transporter protein location, and TfR-1 or FPN-1 protein expression. IRP-1 activity remained constant until full term, when it decreased ( P = 0.01). Placental ferritin ( r = 0.76, P < 0.001) and FPN-1 ( r = 0.44, P < 0.05) expression increased with gestational age. Fetal iron status, as indexed by cord serum ferritin concentration, was inversely related to placental IRP-1 ( r = −0.66, P < 0.001) and IRP-2 ( r = −0.42, P = 0.05) activities. Placental ferritin protein expression correlated better with IRP-1 ( r = −0.45, P = 0.04) than with IRP-2 ( r = −0.35, P = 0.10) activity. Placental TfR-1 and FPN-1 protein expression was independent of fetal or placental iron status and IRP activities. Iron status had no effect on transport protein localization. We conclude that, toward the end of the third trimester of iron-sufficient human pregnancy, the placenta accumulates ferritin and potentially increases placental-fetal iron delivery through increased FPN-1 expression. IRP-1 may have a more dominant role than IRP-2 activity in regulating ferritin expression.

scholarly journals Serum ferritin, cardiovascular risk factors and ischaemic heart diseases: a prospective analysis in the SU.VI.MAX (SUpplementation en VItamines et Minéraux AntioXydants) cohort

2006 ◽  
Vol 9 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Pilar Galan ◽  
Nathalie Noisette ◽  
Carla Estaquio ◽  
Sebastien Czernichow ◽  
Louise Mennen ◽  
...  
Keyword(s):  
Risk Factors ◽  
Serum Ferritin ◽  
Heart Diseases ◽  
Iron Status ◽  
Epidemiological Studies ◽  
Cvd Risk ◽  
Serum Triglycerides ◽  
Ferritin Concentration ◽  
Serum Ferritin Concentration ◽  
A Prospective Study

AbstractBackgroundIron has been suggested to play a role in the development of cardiovascular disease (CVD) through its pro-oxidant properties. However, epidemiological studies on iron status and the risk of CVD have yielded conflicting results. We therefore carried out a prospective study to evaluate the relationship between iron status and CVD in a middle-aged French population.MethodsIn total, 9917 subjects (3223 men aged 45–60 years and 6694 women aged 35–60 years) included in the SU.VI.MAX (SUpplementation en VItamines et Minéraux AntioXydants) cohort were followed prospectively for 7.5 years. All cases of ischaemic heart disease (IHD) were identified and validated. CVD risk factors, haemoglobin and serum ferritin concentrations were measured at baseline.FindingsOf men 4.3%, and of women 37.8%, presented at baseline a serum ferritin concentration <30 μg l−1. During the follow-up, 187 subjects (148 men, 39 women) developed IHD. Serum ferritin was positively associated with total cholesterol, serum triglycerides, systolic and diastolic blood pressure, body mass index and haemoglobin. No linear association was found between serum ferritin and IHD risk in men or in women.ConclusionOur data do not support a major role of iron status in the development of IHD in a healthy general population.

scholarly journals Iron Status of Kenyan Pregnant Women after Adjusting for Inflammation Using BRINDA Regression Analysis and Other Correction Methods

Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 420 ◽  
Author(s):  
Martin Mwangi ◽  
Elizabeth Echoka ◽  
Marthe Knijff ◽  
Lydia Kaduka ◽  
Brenda Werema ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Pregnant Women ◽  
Serum Ferritin ◽  
Iron Status ◽  
Correction Method ◽  
Plasmodium Infection ◽  
Ferritin Concentration ◽  
Regression Methods ◽  
Reactive Protein ◽  
Serum Ferritin Concentration

Serum ferritin concentration is the preferred biomarker to assess population iron status in the absence of inflammation. Interpretation of this biomarker is complicated in populations with a high burden of infection, however, because inflammation increases serum ferritin concentration independently of iron status. We aimed to compare estimates of iron status of Kenyan pregnant women, with circulating ferritin concentrations adjusted for inflammation using newly proposed methods by the BRINDA project, or using previously proposed adjustment methods. We re-analyzed data from pregnant Kenyan women living in a rural area where malaria is highly endemic (n = 470) or in an urban area (n = 402). As proposed by the BRINDA group, we adjusted individual ferritin concentration by internal regression for circulating concentrations of C-reactive protein (CRP) and α1-acid glycoprotein (AGP). Other adjustment methods comprised: (a) arithmetic correction factors based on CRP or AGP; (b) exclusion of subjects with inflammation (CRP >5 mg/L or AGP >1 g/L); and (c) higher ferritin cut-off value (<30 μg/L). We additionally adjusted for Plasmodium infection as appropriate. Lastly, we assessed iron status without adjustment for inflammation. All correction methods increased prevalence of iron deficiency compared to the unadjusted estimates. This increase was more pronounced with the internal regression correction method. The iron deficiency prevalence estimate increased from 53% to 87% in rural Kisumu study and from 30% to 41% in the urban Nairobi study after adjusting for inflammation (CRP and AGP) using the BRINDA internal regression method. When we corrected for both inflammation and Plasmodium infection using the regression correction, it resulted in lower prevalence estimates compared to uninfected women. Application of linear regression methods to adjust circulating ferritin concentration for inflammation leads to markedly decreased point estimates for ferritin concentration and increased estimates for the prevalence of iron deficiency in pregnancy.

scholarly journals Assessment of Iron Status in Association with Excess Alcohol Consumption

1995 ◽  
Vol 32 (6) ◽  
pp. 527-531 ◽  
Author(s):  
C Ford ◽  
F E Wells ◽  
J N Rogers
Keyword(s):  
Serum Ferritin ◽  
Alcohol Intake ◽  
Matched Control ◽  
Iron Status ◽  
Iron Concentration ◽  
Transferrin Saturation ◽  
Control Group ◽  
Ferritin Concentration ◽  
Serum Ferritin Concentration ◽  
Rule Out

Biochemical evidence of iron overload (transferrin saturation greater than 60% and/or serum ferritin concentration greater than 1000 μg/L) was observed in 16% of patients admitted to an alcohol withdrawal unit. No subjects in an age and sex matched control group showed such biochemical changes. Whilst changes in serum ferritin concentration closely correlated with aspartate aminotransferase activity and could be explained by alcohol induced liver damage, the increased transferrin saturation was not similarly explained. In nine patients withdrawal of alcohol resulted in a decrease in transferrin saturation and serum ferritin, the former due to a reduction in serum iron concentration. In patients with high alcohol intake biochemical measures of iron status may be misleading and a decrease in both transferrin saturation and serum ferritin concentration after withdrawal of alcohol may help to rule out the possible diagnosis of hereditary haemochromatosis.

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