Prevalence of childhood anaemia in Brazil: still a serious health problem: a systematic review and meta-analysis

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.

Use of dietary supplements by children and adolescents

OBJECTIVES

Narrative review evaluating the use of dietary supplements by children and adolescents.

DATA SOURCE

The terms "dietary supplements", "children" and "adolescents" were used in combination in the PubMed, MEDLINE, and SciELO databases, between 2000 and 2023, evaluating studies in humans, published in Portuguese, English, French and Spanish.

DATA SYNTHESIS

The use of dietary supplements by children and adolescents has increased in recent decades. The most commonly used supplements are vitamins, minerals, trace elements, proteins, amino acids, melatonin, fatty acids, probiotics and energy drinks.

CONCLUSION

Despite having specific indications, most of the time they are not prescribed by a healthcare professional. The reasons for use are varied. In children, the main reasons are protection against infections, stimulating growth, and poor food intake, with multivitamins and minerals being the most commonly used supplements. In adolescents, they are used to improve athletic performance and attain the "ideal body", with proteins and amino acids being the most often used nutrients. As they are not regulated by health agencies and are sold without a prescription, their unsupervised use can lead to inadequate doses, with inefficiency or overdose risk. As for compounding formulations, or when available in preparations with multiple nutrients, the chance of errors increases. It is essential that pediatricians advise parents and patients about the indications, risks and benefits, prescribing them when necessary.

Hidden hunger - a narrative review

OBJECTIVE

Malnutrition is characterized by situations of undernutrition and obesity resulting from the lack of micronutrients with the greatest impact on children. The objective of this review was to highlight inadequate food consumption, food security, and nutritional inadequacy leading to hidden hunger and the prevention and treatment of the main micronutrient deficiencies in Brazil.

DATA SOURCE

Literature review carried out through a bibliographic survey in PubMed (National Library of Medicine, United States), Lilacs (Latin American and Caribbean Literature in Health Sciences), and SciELO (Scientific Electronic Library Online) databases. The search used the terms Occult hunger, (hidden hunger), and Child, in articles published between 2013 and 2023 in Portuguese, English and Spanish. The search was performed on 06/25/2023.

DATA SYNTHESIS

The lack of micronutrients can occur insidiously and without clinical manifestations, being called hidden hunger. The prevention of nutritional deficiencies is part of the recommended actions in childcare, with healthy eating. Studies were cited related to macro and micronutrient intake deficiencies, both national and international, and strategies to improve micronutrient intake, including routine supplementation of iron, and vitamins D and A. The diagnosis, prevention, and treatment of the main deficiencies in Brazil (iron, vitamin A, vitamin D, zinc), currently adopted, concluded the topic.

CONCLUSION

Zero hunger and zero obesity must be part of the same policy, together with a nutritional education program.

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.

Anaemia among school children of different socioeconomical status in a city of Southern Brazil

Background: Iron deficiency is one of the leading causes of anaemia, with those most affected being children and women of childbearing age, in Brazil there is a scarcity of studies involving the local prevalence of anaemia. Aim: To evaluate anaemia and associated factors in schoolchildren in Santa Cruz do Sul through the analysis of biochemical and haematological markers and parasitological examination of faeces. Subjects and methods: School children from 10 to 12 years of age were evaluated through complete blood count, serum ferritin, C-reactive protein and stool parasitological examination, as well as socio-demographic characteristics and prophylaxis with ferrous sulphate in childhood. Results: It was found that 13.0% of the population was anaemic, girls were very slightly overrepresented among the anaemic children. Only 5.3% had altered haematocrit levels; 26.6% had low Mean Corpuscular Volume levels; 18.4% had low ferritin levels; 2.4% had increased C-reactive protein levels, and 21.7% had altered eosinophils. As for the socioeconomic level, classes A2 and D presented lower haemoglobin levels, as well as class D presenting lower ferritin levels, although without statistical significance. Only 6.0% of the population presented iron-deficiency anaemia and 46.0% of the schoolchildren had used ferrous sulphate supplementation in childhood. Conclusion: The prevalence of anaemia in the studied municipality is low, probably due to the high municipal human development index. Epidemiological studies are essential to characterise the population in a systematic form, to prevent future problems.

Iron-fortified water: a new approach for reducing iron deficiency anemia in resource-constrained settings

A new approach for fortification of drinking water is presented for combating iron deficiency anemia (IDA) worldwide. The idea is to leach Fe from a bed containing granular metallic iron (Fe0), primarily using ascorbic acid (AA). AA forms very stable and bioavailable complexes with ferrous iron (FeII). Calculated amounts of the FeII-AA solution can be added daily to the drinking water of households or day-care centers for children and adults (e.g. hospitals, kindergartens/schools, refugee camps) to cover the Fe needs of the populations. Granular Fe0 (e.g., sponge iron) in filters is regarded as a locally available Fe carrier in low-income settings, and, AA is also considered to be affordable in low-income countries. The primary idea of this concept is to stabilize FeII from the Fe0 filter by using an appropriate AA solution. An experiment showed that up to 12 mg Fe can be daily leached from 1.0 g of a commercial sponge iron using a 2 mM AA solution. Fe fortification of safe drinking water is a practicable, affordable and efficient method for reducing IDA in low-income communities.

The use of RNA-based treatments in the field of cancer immunotherapy

Over the past several decades, mRNA vaccines have evolved from a theoretical concept to a clinical reality. These vaccines offer several advantages over traditional vaccine techniques, including their high potency, rapid development, low-cost manufacturing, and safe administration. However, until recently, concerns over the instability and inefficient distribution of mRNA in vivo have limited their utility. Fortunately, recent technological advancements have mostly resolved these concerns, resulting in the development of numerous mRNA vaccination platforms for infectious diseases and various types of cancer. These platforms have shown promising outcomes in both animal models and humans. This study highlights the potential of mRNA vaccines as a promising alternative approach to conventional vaccine techniques and cancer treatment. This review article aims to provide a thorough and detailed examination of mRNA vaccines, including their mechanisms of action and potential applications in cancer immunotherapy. Additionally, the article will analyze the current state of mRNA vaccine technology and highlight future directions for the development and implementation of this promising vaccine platform as a mainstream therapeutic option. The review will also discuss potential challenges and limitations of mRNA vaccines, such as their stability and in vivo distribution, and suggest ways to overcome these issues. By providing a comprehensive overview and critical analysis of mRNA vaccines, this review aims to contribute to the advancement of this innovative approach to cancer treatment.

Low bioavailability of dietary iron among Brazilian children: Study in a representative sample from the Northeast, Southeast, and South regions

Background

Despite all efforts, iron deficiency anemia remains a serious public health problem among Brazilian children.

Objective

To evaluate dietary iron intake and dietary practices that interfere with the absorption of this nutrient from three regions of Brazil.

Methods

Brazil Kids Nutrition and Health Study is a cross-sectional dietary intake study in children aged 4-13.9 years old designed to investigate nutrient intakes and gaps of Brazilian children in a representative sample of households from Northeast, Southeast and South regions. Nutrient intake was assessed based on multiple-pass 24-h dietary recall and U.S. National Cancer Institute method was used to estimate usual micronutrients intakes and compliance with Dietary Reference Intakes.

Results

Five hundred sixteen individuals participated in the study (52.3% male). The top three most consumed food sources of iron were products of plant origin. Food sources of animal origin contributed with <20% of the total iron intake. Vitamin C intake was adequate, but the concomitant consumption of food sources of vitamin C with plant food sources of iron was not common. On the other hand, the concomitant intake of plant food sources of iron with food sources of iron chelators (e.g., coffee and teas) was frequent.

Conclusions

Adequate iron intake was observed in all three regions in Brazil. Children's diet showed low iron bioavailability and insufficient consumption of food sources of iron absorption stimulants. Frequent presence of iron chelators and inhibitors of iron absorption might help to explain the high prevalence of iron deficiency in the country.

Milk beverages can reduce nutrient inadequacy among Brazilian pre-school children: a dietary modelling study

BACKGROUND

Previous studies found high prevalence of inadequate intakes of vitamins E, D and K, calcium and potassium among Brazilian pre-school children, with suboptimal consumption of dairy products. Dietary modelling was applied to determine the theoretical impact of improving dairy products consumption on nutrient adequacy in 4-5-year-old Brazilian children.

METHODS

Adherence to the dairy recommendation of two servings/day was calculated using data from the Brazil Kids Nutrition and Health Study (KNHS) (n = 228). Two modelling scenarios were applied to test the impact on nutrient intakes of (1) adding one or two servings of a frequently consumed cow's milk or a widely available fortified alternative: pre-school children milk (PCM), and of (2) substituting the current milk consumed by PCM. Mean nutrient intakes and percentage of children adhering to the nutrient recommendations were determined at baseline and after applying modelling scenarios.

RESULTS

Seventy-six percent (n = 174) of children did not meet the recommended daily two servings of dairy products, 56% had less than one serving of dairy products on the day of recall. The mean consumption of whole milk (fortified and unfortified) was 147 g/d, yoghurt 114 g/d and cheese 34 g/d. The addition of one serving of cow's milk demonstrated a 17% reduction in calcium inadequacy, 18% reduction in vitamin A and 3% reduction in zinc inadequacy. Adding one serving of PCM further reduced calcium inadequacy from 87 to 41%, vitamin E from 81 to 37%, and zinc inadequacy by 10%. Replacing the child's current milk with a PCM resulted in further reduction of micronutrient inadequacies, including calcium, vitamin D and vitamin E.

CONCLUSIONS

Dairy products consumption in pre-school children should be encouraged to reduce nutrient inadequacies. In particular, consumption of PCM would help to reduce calcium, vitamin D and vitamin E inadequacy, nutrients of concern in this population.

Wildmeat consumption and child health in Amazonia

Consuming wildmeat may protect against iron-deficiency anemia, a serious public health problem globally. Contributing to debates on the linkages between wildmeat and the health of forest-proximate people, we investigate whether wildmeat consumption is associated with hemoglobin concentration in rural and urban children (< 5 years old) in central Brazilian Amazonia. Because dietary practices mediate the potential nutritional benefits of wildmeat, we also examined whether its introduction into children's diets is influenced by rural/urban location or household socio-economic characteristics. Sampling 610 children, we found that wildmeat consumption is associated with higher hemoglobin concentration among the rural children most vulnerable to poverty, but not in the least vulnerable rural, or urban children. Rural caregivers share wildmeat with children earlier-in-life than urban caregivers, potentially because of cultural differences, lower access to domesticated meat, and higher wildmeat consumption by rural households (four times the urban average). If wildmeat becomes unavailable through stricter regulations or over-harvesting, we predict a ~ 10% increased prevalence of anemia among extremely poor rural children. This modest protective effect indicates that ensuring wildmeat access is, alone, insufficient to control anemia. Sustainable wildlife management could enhance the nutritional benefits of wildlife for vulnerable Amazonians, but reducing multidimensional poverty and improving access to quality healthcare are paramount.