Prevalence and Factors Associated with Iron Deficiency and Anemia among Residents of Urban Areas of São Paulo, Brazil

Abstract

Anemia is a worldwide concern. This cross-sectional population-based study examined the prevalence of iron-deficiency anemia (IDA) among residents of São Paulo (n = 898; 12–93 years), considering sociodemographic factors, dietary iron inadequacy, and food contributors to iron intake. Blood cell count and iron biomarkers were quantified. Dietary iron intake was measured using two 24-h dietary recalls. Iron intake inadequacy was estimated using a probabilistic approach. The prevalence of anemia was 6.7%, depleted iron stores 5.1%, and IDA 1.1%. Women of all age groups, older adults, and those who were underweight or obese had the highest prevalence of anemia, and female adolescents had the highest prevalence of depleted iron stores. Female adolescents and adults were more vulnerable to depleted iron stores. Male adults and older adults had a considerable prevalence of iron overload. Except for female adolescents and adults, all groups had mild probabilities of inadequate iron intake. The main food iron contributor was wheat flour. Hemoglobin concentrations were directly associated with being an adult, having a higher income, and inversely associated with being female. Serum ferritin concentrations were directly associated with age and inversely correlated with female sex. Residents of São Paulo had a low prevalence of anemia, iron deficiency, and IDA, and sociodemographic factors interfered with these parameters.

Dietary iron intake over two post-fortification periods in Brazil: data from the National Dietary Surveys 2008–2009 and 2017–2018

“…The estimated mean dietary Fe intakes, after stratifying by sex-age groups, ranged from 9·5 to 13·6 mg/d in 2008–2009 and from 8·9 to 13·2 mg/d in 2017–2018. Despite a lack of national population-based Fe intake data from the pre-fortification era, our mean values showed similarities to those described by Vieira et al (2017) and Sales et al (2021) for representative samples of adolescents, adults and elderly residents in São Paulo-SP, the largest Brazilian city, in 2008 (7·8 to 15·2 mg/d) (25) and in 2015 (7·8 to 12·0 mg/d) (26) , while significantly higher from those found in 2003 (3·9 to 7·0 mg/d) (25) . These data are in line with improvements in Fe intake and population status among countries that have adopted strategies for flour fortification with Fe (27) .…”

“…The dietary Fe intake of Brazilians aged ≥ 10 years remained almost unchanged over an interval of 10 years in the post-fortification era, according to data from the two largest national (25) and in 2015 (7•8 to 12•0 mg/d) (26) , while significantly higher from those found in 2003 (3•9 to 7•0 mg/d) (25) . These data are in line with improvements in Fe intake and population status among countries that have adopted strategies for flour fortification with Fe (27) .…”

Assessment of Heme and Non-Heme Iron Intake and Its Dietary Sources among Adults in Armenia

“…In addition, the bioavailability of iron should be considered when deciding fortification levels, the high presence of antinutritional factors might also reduce the favorable impact of fortification programs. Moreover, the high consumption of iron-fortified wheat or maize flours may increase the risk of becoming overweight [ 35 ]; thus, advocacy of iron fortification should not become a strenuous promotion of carbohydrate-rich diets. In addition, the fraction of people with hemochromatosis deserves attention, as iron overload can cause serious chronic illness.…”

Effectiveness of Nutrition Education on Knowledge of Anemia and Hemoglobin Level in Female Adolescents Aged 12-19 Years: a Systematic Reviews and Meta-Analysis

“…The majority of the iron in the body is contained in hemoglobin-like protein, which red blood cells contain. The oxygen in the blood is carried by hemoglobin into the lungs and all of the body's tissues 5 . Due to lower iron reserves in general, women are more susceptible to anemia than men, and the advent of menstruation increases the need for iron to make up for menstrual blood loss.…”