Yibby Forero

Provision of a School Snack Is Associated with Vitamin B-12 Status, Linear Growth, and Morbidity in Children from Bogotá, Colombia

In 2004, Bogotás Secretary of Education (SED) initiated a snack program in public primary schools. A midmorning food ration was provided free of charge to children to supplement 30 and 50% of their daily requirements of energy and iron, respectively. The purpose of this study, an observational investigation of 3202 children ages 5-12 y, was to examine whether the snack program improved childrens nutritional and health status. We measured micronutrient levels (plasma ferritin and vitamin B-12, and erythrocyte folate), anthropometry, and reported morbidity during the first semester of the 2006 school year. After adjusting for socioeconomic status and other school interventions, children at schools receiving the snack (n = 1803) had greater increases in plasma vitamin B-12 (42 pmol/L; P < 0.0001) from baseline to 3 mo of follow-up than children at schools not receiving the snack (n = 1399). They also experienced a smaller decrease in height-for-age Z-scores than children who did not receive the snack (P = 0.001). Provision of the SED snack was associated with significantly fewer reported days with morbidity symptoms (e.g. cough with fever, diarrhea with vomiting), 44% fewer doctor visits (P = 0.02), and 23% fewer days of school absenteeism (P = 0.03). The snack was not related to ferritin or folate levels. In conclusion, provision of a school-administered snack was related to improved vitamin B-12 status and linear growth and decreased reported morbidity. Although provision of the snack was not related to BMI changes over a 4-mo period, snack components such as candy and sugar-sweetened beverages should be replaced with healthier options, as the rates of child overweight in Colombia are not negligible.

Intestinal Protozoan Infections in Relation to Nutritional Status and Gastrointestinal Morbidity in Colombian School Children

While Giardia duodenalis infection has been consistently associated with nutrient malabsorption and stunting in children, the effects of other protozoans on nutritional status or gastrointestinal morbidity are less clear. We sought to determine whether infection with common intestinal protozoans including Giardia duodenalis, Entamoeba coli and Blastocystis hominis was associated with anthropometric and micronutrient status, gastrointestinal symptoms, visits to the doctor or school absenteeism in children 5-12 years of age from Bogotá, Colombia. We obtained stool samples from 442 children enrolled in primary schools in 2006 and examined the presence of intestinal protozoans in relation to height, body mass index, plasma concentrations of vitamins A and B12, ferritin and zinc and erythrocyte folate. In addition, we examined the associations between protozoan infections and the incidence of common gastrointestinal symptoms, which were registered prospectively in morbidity diaries. The prevalence rates of G. duodenalis, E. coli and B. hominis infection were 6.3, 23.1 and 22.4%, respectively. Giardia infection was associated with lower height-for-age z-score (p = 0.04), whereas E. coli infection was associated with low erythrocyte folate (p = 0.04), and B. hominis infection was related to higher vitamin A levels (p = 0.05). Infection with E. coli was also associated with a significantly higher incidence of fever but fewer visits to the doctor, while B. hominis infection was associated with significantly less diarrhea, diarrhea with vomiting, doctor visits and school absenteeism. In conclusion, G. duodenalis and E. coli infections were associated with indicators of poor nutritional status in this population, while B. hominis was related to apparently decreased morbidity.

Micronutrient status and global DNA methylation in school-age children.

Aberrations in global LINE-1 DNA methylation have been related to risk of cancer and cardiovascular disease. Micronutrients including methyl-donors and retinoids are involved in DNA methylation pathways. We investigated associations of micronutrient status and LINE-1 methylation in a cross-sectional study of school-age children from Bogotá, Colombia. Methylation of LINE-1 repetitive elements was quantified in 568 children 5–12 years of age using pyrosequencing technology. We examined the association of LINE-1 methylation with erythrocyte folate, plasma vitamin B12, vitamin A ferritin (an indicator of iron status) and serum zinc concentrations using multivariable linear regression. We also considered associations of LINE-1 methylation with socio-demographic and anthropometric characteristics. Mean (± SD) LINE-1 methylation was 80.25 (± 0.65) percentage of 5-mC (%5-mC). LINE-1 methylation was inversely related to plasma vitamin A. After adjustment for potential confounders, children with retinol levels higher than or equal to 1.05 µmol/L showed 0.19% 5-mC lower LINE-1 methylation than children with retinol levels lower than 0.70 µmol/L. LINE-1 methylation was also inversely associated with C-reactive protein, a marker of chronic inflammation, and female sex. We identified positive associations of maternal body mass index and socioeconomic status with LINE-1 methylation. These associations were not significantly different by sex. Whether modification of these exposures during school-age years leads to changes in global DNA methylation warrants further investigation.

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

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 childs age, mothers age, households socioeconomic stratum, and family income. Low ferritin was related to 3.6 g/l lower hemoglobin concentration (95% confidence interval=−6.0, −1.3). 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 −6.0 g/l (95% confidence interval=−7.2, −4.9; P for trend <0.0001). This difference was greatest among children with vitamin B12 concentration <148 pmol/l (−11.5 g/l), followed by children with vitamin B12 concentration 148–221 pmol/l (−7.7 g/l), and smallest in children with vitamin B12 concentration >221 pmol/l (−5.7 g/l); P for interaction=0.04.Conclusions:Hemoglobin concentration is inversely related to erythrocyte folate concentrations in a setting where folate fortification was adopted more than a decade ago. The impact of improving vitamin B12 status on this inverse relationship should be examined.

Relation between Vitamin B12 and Folate Status, and Hemoglobin Concentration and Parasitemia during Acute Malaria Infections in Colombia

Anemia is a common complication of human malaria. Since micronutrient deficiencies are highly prevalent in malaria-endemic areas and appear to contribute to anemia etiology, we conducted a cross-sectional study in Tumaco, Colombia, to examine the associations between plasma vitamin B12 or erythrocyte folate concentrations and hemoglobin (Hb) among 96 adults with predominantly Plasmodium falciparum malaria. Prevalence of folate and vitamin B12 deficiencies was 26.0 and 26.6%, respectively. There was an inverse, linear relation between folate and Hb concentrations. Adjusted difference in Hb between lowest and highest folate quartiles was 1g/dL (p=0.04; p, test for trend=0.01). Vitamin B12 was not associated with Hb concentrations and did not modify the associations between folate and Hb. Incidentally, body mass index (BMI) was inversely associated with parasitemia and risk of clinical malaria. Future longitudinal studies are warranted to determine the potential pathophysiological role of folate in malaria-related anemia.