Association of Family Income and Risk of Food Insecurity With Iron Status in Young Children.

Importance: Iron deficiency (ID) has the greatest prevalence in early childhood and has been associated with poor developmental outcomes. Previous research examining associations of income and food insecurity (FI) with ID is inconsistent. Objective: To examine the association of family income and family risk of FI with iron status in healthy young children attending primary care. Design, Setting, and Participants: This cross-sectional study included 1245 children aged 12 to 29 months who attended scheduled primary care supervision visits from 2008 to 2018 in Toronto, Canada, and the surrounding area. Exposures: Family income and risk of FI were collected from parent-reported questionnaires. Children whose parents provided an affirmative response to the 1-item FI screen on the Nutrition Screening Tool for Every Toddler or at least 1 item on the 2-item Hunger Vital Sign FI screening tool were categorized as having family risk of FI. Main Outcomes and Measures: Iron deficiency (serum ferritin level <12 ng/mL) and ID anemia (IDA; serum ferritin level <12 ng/mL and hemoglobin level <11.0 g/dL). All models were adjusted for age, sex, birth weight, body mass index z score, C-reactive protein level, maternal education, breastfeeding duration, bottle use, cow's milk intake, and formula feeding in the first year. Results: Of 1245 children (595 [47.8%] girls; median [interquartile range] age, 18.1 [13.3-24.0] months), 131 (10.5%) were from households with a family income of less than CAD $40 000 ($29 534), 77 (6.2%) were from families at risk of FI, 185 (14.9%) had ID, and 58 (5.3%) had IDA. The odds of children with a family income of less than CAD $40 000 having ID and IDA were 3 times higher than those of children in the highest family income group (ID: odds ratio [OR], 3.08; 95% CI, 1.66-5.72; P < .001; IDA: OR, 3.28; 95% CI, 1.22-8.87; P = .02). Being in a family at risk of FI, compared with all other children, was not associated with ID or IDA (ID: OR, 0.43; 95% CI, 0.18-1.02; P = .06; IDA: OR, 0.16; 95% CI, 0.02-1.23; P = .08). Conclusions and Relevance: In this study, low family income was associated with increased risk of ID and IDA in young children. Risk of FI was not a risk factor for ID or IDA. These findings suggest that targeting income security may be more effective than targeting access to food to reduce health inequities in the prevention of iron deficiency.