Heme Iron Concentrate and Iron Sulfate Added to Chocolate Biscuits: Effects on Hematological Indices of Mexican Schoolchildren

A comparative analysis of heme vs non-heme iron administration: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

Bioavailability studies and observational evidence suggest that heme iron (HI) may have greater impact on iron status indicators compared with non-heme iron (NHI). This systematic review and meta-analysis aimed to review the current evidence on the effect of the administration of HI compared with NHI for improving iron status in non-hospitalized population groups.

METHODS

We searched Pubmed, CENTRAL, Scopus, Web of Science, and LILACS from inception to July 2024. There was no language restriction or exclusion based on age or iron status. Only randomized controlled trials comparing HI with NHI were considered. A random-effects meta-analysis was performed to compare the effect of treatments for iron status indicators and total side effects (including gastrointestinal side effects). We measured the certainty of the evidence (CoE) using GRADE assessment.

RESULTS

After screening 3097 articles, 13 studies were included. Most of the interventions used HI in low doses combined with NHI. The meta-analysis showed higher hemoglobin increases in children with anemia or low iron stores receiving HI (MD 1.06 g/dL; 95% CI: 0.34; 1.78; CoE: very low). No statistically significant difference between interventions were found for any iron status indicator in the other population subgroups (CoE: very low). Participants receiving HI had a 38% relative risk reduction of total side effects compared to NHI (RR 0.62; 95% CI 0.40; 0.96; CoE: very low).

CONCLUSION

The current evidence comparing HI with NHI is very limited, preliminary findings suggest that interventions using HI may result in fewer side effects and may be superior in children with iron deficiency or anemia. However, given the very low certainty of the evidence, these results need further investigation through high-quality clinical trials.

PROTOCOL REGISTRATION

CRD42023483157.

Hemin with Peroxidase Activity Can Inhibit the Oxidative Damage Induced by Ultraviolet A

Excessive reactive oxygen species (ROS), a highly reactive substance that contains oxygen, induced by ultraviolet A (UVA) cause oxidative damage to skin. We confirmed that hemin can catalyze the reaction of tyrosine (Tyr) and hydrogen peroxide (H₂O₂). Catalysis was found to effectively reduce or eliminate oxidative damage to cells induced by H₂O₂ or UVA. The scavenging effects of hemin for other free-radical ROS were also evaluated through pyrogallol autoxidation, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·)-scavenging assays, and phenanthroline–Fe²⁺ assays. The results show that a mixture of hemin and tyrosine exhibits strong scavenging activities for H₂O₂, superoxide anion (O₂⁻·), DPPH·, and the hydroxyl radical (·OH). Furthermore, the inhibition of oxidative damage to human skin keratinocyte (HaCaT) cells induced by H₂O₂ or UVA was evaluated. The results show that catalysis can significantly reduce the ratio of cell apoptosis and death and inhibit the release of lactate dehydrogenase (LDH), as well as accumulation of malondialdehyde (MDA). Furthermore, the resistance to apoptosis was found to be enhanced. These results show that the mixture of hemin and tyrosine has a significantly protective effect against oxidative damage to HaCaT cells caused by UVA, suggesting it as a protective agent for combating UVA damage.

How to use… iron studies

Iron studies are frequently requested in paediatric practice. They are useful both as a diagnostic tool and as a way of monitoring certain conditions, particularly those causing iron overload. This article outlines the physiology of iron metabolism and discusses laboratory aspects of performing iron studies, including factors influencing interpretation. Clinical scenarios are used to highlight how the tests can be used in different clinical situations.

Vitamin D3 supplementation for 8 weeks leads to improved haematological status following the consumption of an iron-fortified breakfast cereal: a double-blind randomised controlled trial in iron-deficient women

The effect of 38 µg (1500 IU) daily vitamin D3 supplementation, consumed with an Fe-fortified breakfast cereal for 8 weeks, on haematological indicators in Fe-deficient female subjects was investigated. Fifty Fe-deficient subjects (plasma ferritin concentration <20 µg/l; mean age: 27·4 (sd 9·4) years) were randomised to consume an Fe-fortified breakfast cereal containing 9 mg of Fe daily, with either a vitamin D3 supplement or placebo. Blood samples were collected at baseline, interim (4 weeks) and post-intervention (8 weeks) for measurement of Fe and vitamin D status biomarkers. The effect of intervention was analysed using mixed-model repeated-measures ANOVA. Significant increases were observed in two main haematological indices: Hb concentration and haematocrit level from baseline to post-intervention in the vitamin D group but not in the placebo group. The increase from baseline to post-intervention in Hb concentration in the vitamin D group (135 (sd 11) to 138 (sd 10) g/l) was significantly higher compared with the placebo group (131 (sd 15) to 128 (sd 13) g/l) (P=0·037). The increase in haematocrit level from baseline to post-intervention was also significantly higher in the vitamin D group (42·0 (sd 3·0) to 43·8 (sd 3·4) %) compared with the placebo group (41·2 (sd 4·3) to 40·7 (sd 3·6) %) (P=0·032). Despite the non-significant changes in plasma ferritin concentration, this study demonstrates that 38 µg supplemental vitamin D, consumed daily, with Fe-fortified breakfast cereal led to improvement in Hb concentration and haematocrit levels in women with low Fe stores. These findings may have therapeutic implications in the recovery of Fe status in Fe-deficient populations at a healthcare level.