Micronutrient Deficiencies and Anemia in Children in Mexico: Results From the National Health and Nutrition Survey (ENSANUT)

Abstract

Objectives: To examine the burden of anemia and micronutrient deficiencies, and associations between micronutrient status and anemia in children (1–11 y) in Mexico. Methods: Data from the National Health and Nutrition Survey (ENSANUT 2018) were analyzed to determine the burden of anemia and micronutrient deficiencies (iron, vitamin B12, vitamin A) in a nationally-representative sample of 4,891 children 1 to 11 years of age (1 to < 5 y: 1,337; 5–11 y: 3,554). Hemoglobin (Hb) was measured via HemoCue and venous blood samples were collected, processed, and stored at < -80°C until analysis. Serum ferritin (SF), C-reactive protein (CRP) and vitamin B12 concentrations were measured via immunoassays. Serum retinol was measured via HPLC. Hemoglobin was adjusted for altitude; anemia (< 5y:Hb < 11.0 g/dL; 5–11 y: < 11.5 g/dL) and iron deficiency (ID; < 5y: < 12.0 μg/L; 5– 11 y: < 15.0 μg/L) were defined using age-specific cut-offs. Iron insufficiency was defined as SF < 20.0 μg/L, and inflammation as CRP> 5.0 mg/L. Vitamin B12 deficiency and insufficiencywere defined as < 148 and < 221 pmol/L, and vitamin A deficiency was defined as retinol < 20 μg/dL. Survey linear and logistic regression were used to examine associations ofmicronutrient biomarkers with hemoglobin concentrations and odds of anemia. Results: Serum ferritin concentrations (β [SE]: 0.0003, p < 0.001) and serum retinol levels (0.0005, p<0.001) were associated with higher hemoglobin levels, while iron deficiency (–0.57 [0.03], p < 0.001), iron insufficiency (–0.54 [0.02]; p < 0.001), and vitamin A deficiency (–0.53 [0.01], p<0.0001)were associated with lower hemoglobin levels. In analyses of anemia, the odds of anemia were 11% lower per 10 μg/L increase in serum ferritin (OR [95% CI]: 0.89 [0.84–0.93], p < 0.001) and 34% lower per 10 μg/dL increase in serum retinol (OR: 0.66 [0.57–0.77], p < 0.001), while iron deficiency (OR: 2.22 [1.49–3.29], p < 0.001) and iron insufficiency (OR: 1.74 [1.32–2.30]; p = 0.0001) were associated with higher odds of anemia. Conclusions: Findings suggest that the burden of anemia and micronutrient deficiencies are high in children in Mexico, and lower iron and vitamin A status were associated with increased odds of anemia.