Hemoglobin concentration is inversely associated with erythrocyte folate concentrations in Colombian school-age children, especially among children with low vitamin B12 status

Abstract

Background: While the majority of cases of nutritional anemia in developing countries are caused by iron deficiency, other micronutrient deficiencies may also be involved. In Colombia, it was recently reported that 38% of school children were anemic; yet, the rate of iron deficiency was only 3.6%. Objective: To determine if micronutrients other than iron were responsible for low hemoglobin concentrations in Colombian school children. Methods: We examined hemoglobin concentrations in relation to plasma ferritin, vitamin A, vitamin B12, and erythrocyte folate levels in a representative sample of 2812 low-and middle-income children (5-12 years) from Bogotá, Colombia. Results: In multivariate analysis, hemoglobin concentration was positively associated with child's age, mother's age, household's socioeconomic stratum, and family income. Low ferritin was related to 3.6 g/l lower hemoglobin concentration (95% confidence interval ¼ À6.0, À1.3). Unexpectedly, we found an inverse trend in hemoglobin concentration by quartiles of erythrocyte folate; the adjusted hemoglobin concentration difference between the highest and lowest folate quartiles was À6.0 g/l (95% confidence interval ¼ À7.2, À4.9; P for trend o0.0001). This difference was greatest among children with vitamin B12 concentration o148 pmol/l (À11.5 g/l), followed by children with vitamin B12 concentration 148-221 pmol/l (À7.7 g/l), and smallest in children with vitamin B12 concentration 4221 pmol/l (À5.7 g/l); P for interaction ¼ 0.04.

Valores séricos de ácido fólico en un grupo de pacientes mayores de 18 años de edad en un hospital de alta complejidad

“…Por otra parte, se ha descrito que en pacientes colombianos con enfermedad cardiovascular se presentan valores significativamente menores de ácido fólico en suero frente a sus controles sanos [19]; también se han identificado diferencias de las cantidades de folato entre poblaciones. Por ejemplo, el estudio de Caicedo y colaboradores [20] estableció una prevalencia del 26 % de deficiencia de folato eritrocitario en pacientes con malaria, lo que contrasta con una prevalencia de menos del 1 % de la misma deficiencia, en población escolar pediátrica de Bogotá [21]. Sin embargo, no hay un referente en la literatura que describa localmente las concentraciones de ácido fólico en sujetos con diversos rangos de edad y que establezcan si hay diferencias según grupos etarios y sexo.…”

Vitamin B-12 Deficiency in Children Is Associated with Grade Repetition and School Absenteeism, Independent of Folate, Iron, Zinc, or Vitamin A Status Biomarkers

“…Phlebotomists obtained a sample of venous blood from 88% of participating children after an overnight fast. Samples were collected in EDTA-coated tubes and transported the same day, on ice and protected from sunlight, to the National Institute of Health in Bogota, where biochemical analyses were performed according to methods described previously (24). Hemoglobin concentrations were quantified with a hemiglobincyanide method, whereas mean corpuscular volume (MCV) was determined as part of a complete blood count.…”

Determinants of Anemia and Hemoglobin Concentration in Haitian School-Aged Children

“…7 One study among school-aged children in Colombia found that Hb concentration was inversely related to erythrocyte folate concentrations, in particular, among children with low vitamin B 12 status. 31 Although we were not able to directly examine status for these nutrients, consumption of ASF as the only dietary source of vitamin B 12 might be considered a proxy marker. 32 We found a positive trend for ASF and Hb concentrations (P = 0.07) and for ASF reducing the odds of severe anemia (P = 0.06) in longitudinal modeling.…”