This study aimed to assess hemoglobin concentration and its association with oral contraceptive (OC) use, food insecurity (FI) and dietary iron availability (DIA) in adult women of reproductive age (20–44 years). This is a population-based cross-sectional study that analysed 505 women living in favelas and urban communities in a capital city in northeastern Brazil. Hemoglobin concentration was determined using capillary blood samples. FI and DIA were assessed using the Brazilian Food Insecurity Scale and the 24-h food recall, respectively. Association analysis was carried out using logistic regression. A directed acyclic graph (DAG) was designed to illustrate the causal paths between hemoglobin concentration and DIA. A significance level of 5 % was adopted. Low hemoglobin concentrations (11·2 g/dl: (1·79)) and a high prevalence of anaemia (64·0 %) were observed; 28·7 % used OC (28·7 %) and 76·4 % were in FI. An average energetic intake of 1495 kcal/d (482·0) and 0·46 mg/d (0·27) of DIA were also observed. In the DAG-guided multivariable analysis, it was observed that hemoglobin concentrations ≥ 12 mg/dl were directly associated with higher DIA (OR: 1·67; 95 % CI (1. 08, 2·59)) and OC use (OR: 1·67; 95 % CI (1·10, 2·55)) and inversely associated with mild FI (OR: 0·60; 95 % CI (0·37, 0·96)) or severe FI (OR: 0·37; 95 % CI: (0·18, 0·76)). Women taking OC and with a higher DIA were less likely to have low hemoglobin concentrations, while those in the context of FI were in the opposite situation.

The final stage of Fe deficiency is Fe deficiency anaemia, with repercussions for human health, especially in children under 5 years of age. Studies conducted in Brazilian public daycare centres show high prevalence of anaemia. The present study aims to evaluate the availability of Fe in the meals of the Municipal Centers of Early Childhood Education in Maceió. The experimental design comprises selection of algorithms, menu evaluation, calculation of the estimates, comparison between the estimates obtained and the recommendations, and analysis of correlation between meal constituents, and of the concordance between the absorbable Fe estimates. Four algorithms were selected and a monthly menu consisting of 22 d. The correlation analysis showed a moderate positive correlation to animal tissue (AT) v. non-heme iron (r = 0·42; P = 0·04), and negative to AT v. Ca (r = −0·54; P = 0·09) and Ca v. phytates (r = −0·46, P = 0·03). Estimates of absorbable Fe ranged from 0·23 to 0·44 mg/d. The amount of Fe available, unlike the total amount of Fe offered, does not meet the nutritional recommendations on most school days. The Bland–Altman analysis indicated that the Monsen and Balinfty and Rickard et al. showed greater agreement. The results confirm the need to adopt strategies to increase the availability of Fe in school meals.