Daily and Weekly Iron Supplementations are Effective in Increasing Hemoglobin and Reducing Anemia in Infants

A Systematic Review of Isotopically Measured Iron Absorption in Infants and Children Under 2 Years

BACKGROUND

Iron is an essential element for critical biological functions, with iron deficiency negatively affecting growth and brain development and iron excess associated with adverse effects. The goal of this review is to provide a comprehensive assessment of up-to-date evidence on iron absorption measured isotopically in children, preterm infants, and full-term infants, up to 24 months of age.

METHODS

Search databases included Pubmed, Cochrane, Web of Science, and Scopus from a date range of 1 January 1953 to 22 July 2024. The included articles were experimental studies with iron absorption outcomes measured by isotopic techniques. The risk of bias was assessed using the Cochrane Risk of Bias Tool.

RESULTS

A total of 1594 records were identified from databases, and 37 studies were included in the quality review with a total of 1531 participants. Article results were grouped by study commonality: absorption and red blood cell incorporation, type of milk feedings, additives to improve absorption, how and when to supplement with iron, and iron forms and complimentary foods.

CONCLUSIONS

The results from this review support the current recommendations of oral iron supplementation. Iron from breast milk has high bioavailability, and unmodified cow's milk reduces iron absorption. Supplemental iron is required at 4-6 months for healthy, full-term infants and sooner for preterm infants. Ascorbic acid increases iron absorption in full-term infants and children. Lactoferrin and prebiotics are promising candidates for enhancing iron absorption, but they require further investigation. Research evidence of iron absorption mechanisms and modulating factors in preterm infants is limited and should be a research priority.

Prevalence of iron-deficiency anaemia in Brazilian children under 5 years of age: a systematic review and meta-analysis

Fe-deficiency anaemia is considered an important public health problem both in wealthier countries and in those of medium and low income, especially in children under 5 years of age. The shortage of studies with national representativity in medium-income countries, such as Brazil, prevents the knowledge of the current situation and its associated factors. We conducted a systematic review and meta-analysis to estimate the pooled prevalence of Fe-deficiency anaemia in Brazilian children under 5 years of age and determined the factors involved in the variability of the estimates of prevalence. We collected fifty-seven studies from the databases MEDLINE, LILACS and Web of Science, along with the reference lists of included articles. We contacted authors for unpublished data. We did not restrict publication timespan and language. This systematic review and meta-analysis was reported according to the guidelines by PRISMA. The pooled prevalence of anaemia in Brazil was 40·2 (95 % CI 36·0, 44·8) %. The age range of the child and the period of data collection were associated with the anaemia prevalence. The pooled prevalence of anaemia was higher in children under 24 months of age (53·5 v. 30·7 %; P < 0·001) and in studies with data collected before 2004 (51·8 v. 32·6 %; P = 0·001). The efforts made by the Brazilian government were successful in the reduction of anaemia in children under 5 years of age in Brazil in the evaluated period. However, prevalence remains beyond acceptable levels for this population group.

Dealing with iron metabolism in rice: from breeding for stress tolerance to biofortification

Iron is a well-known metal. Used by humankind since ancient times in many different ways, this element is present in all living organisms, where, unfortunately, it represents a two-way problem. Being an essential block in the composition of different proteins and metabolic pathways, iron is a vital component for animals and plants. That is why iron deficiency has a severe impact on the lives of different organisms, including humans, becoming a major concern, especially in developing countries where access to adequate nutrition is still difficult. On the other hand, this metal is also capable of causing damage when present in excess, becoming toxic to cells and affecting the whole organism. Because of its importance, iron absorption, transport and storage mechanisms have been extensively investigated in order to design alternatives that may solve this problem. As the understanding of the strategies that plants use to control iron homeostasis is an important step in the generation of improved plants that meet both human agricultural and nutritional needs, here we discuss some of the most important points about this topic.

The Effect of Low Dose Iron and Zinc Intake on Child Micronutrient Status and Development during the First 1000 Days of Life: A Systematic Review and Meta-Analysis

Adequate supply of micronutrients during the first 1000 days is essential for normal development and healthy life. We aimed to investigate if interventions administering dietary doses up to the recommended nutrient intake (RNI) of iron and zinc within the window from conception to age 2 years have the potential to influence nutritional status and development of children. To address this objective, a systematic review and meta-analysis of randomized and quasi-randomized fortification, biofortification, and supplementation trials in women (pregnant and lactating) and children (6–23 months) delivering iron or zinc in doses up to the recommended nutrient intake (RNI) levels was conducted. Supplying iron or zinc during pregnancy had no effects on birth outcomes. There were limited or no data on the effects of iron/zinc during pregnancy and lactation on child iron/zinc status, growth, morbidity, and psychomotor and mental development. Delivering up to 15 mg iron/day during infancy increased mean hemoglobin by 4 g/L (p < 0.001) and mean serum ferritin concentration by 17.6 µg/L (p < 0.001) and reduced the risk for anemia by 41% (p < 0.001), iron deficiency by 78% (ID; p < 0.001) and iron deficiency anemia by 80% (IDA; p < 0.001), but had no effect on growth or psychomotor development. Providing up to 10 mg of additional zinc during infancy increased plasma zinc concentration by 2.03 µmol/L (p < 0.001) and reduced the risk of zinc deficiency by 47% (p < 0.001). Further, we observed positive effects on child weight for age z-score (WAZ) (p < 0.05), weight for height z-score (WHZ) (p < 0.05), but not on height for age z-score (HAZ) or the risk for stunting, wasting, and underweight. There are no studies covering the full 1000 days window and the effects of iron and zinc delivered during pregnancy and lactation on child outcomes are ambiguous, but low dose daily iron and zinc use during 6–23 months of age has a positive effect on child iron and zinc status.

Prevention and Treatment of Anemia in Infants through Supplementation, Assessing the Effectiveness of Using Iron Once or Twice Weekly

BACKGROUND

The objective of this study was to compare the effect of once weekly iron supplementation (IS) versus twice weekly, on hemoglobin (Hb) levels and anemia prevalence.

METHODS

In this cluster-randomized clinical trial study, we evaluated infants aged 6-18 months. Length of intervention: 16 weeks. Infants were cluster randomized to either 25 mg elemental iron once weekly (Group-A) or twice weekly (Group-B). Primary outcome variables were change in Hb concentration and anemia prevalence. Two biochemical evaluations were performed to determine Hb concentrations, before and after intervention.

RESULTS

For Group-A, at baseline, mean Hb concentration was 10.8 ± 1.18 g/dl and after intervention 11.2 ± 1.07 g/dl,p = 0.12; anemia prevalence was 52.5% at baseline and 37.5% after intervention,p = 0.18; Group-B, mean baseline Hb was 10.7 ± 1.04 g/dl, and 11.3 ± 0.91 g/dl after intervention,p = 0.002; anemia prevalence reduced from 57.9 to 36.8%.

CONCLUSIONS

Both once and twice weekly IS increased mean Hb concentration; however, twice weekly supplementation provided more significant results.