Multiple Micronutrient Defficiencies During Early Childhood / Монголын Анагаах Ухаан

ABSTRACT

Introduction. The high rate of malnutrition in young Mongolian children is a serious issue. Anemia, stunting and rickets have all been identified as significant problems. Low levels of serum folate have been reported among some young children in two previous surveys. Zinc is a growth-limiting micronutrient that may contribute to the persistent stunting in young Mongolian children. The traditional rice and wheat-based complementary foods used for young child feeding are likely to be inadequate in zinc. Certainly, the overall prevalence of stunting in Mongolia (i.e., 20%) is suggestive of substantial risk of zinc deficiency. It is possible that co-existing low selenium status may exacerbate zinc deficiency, because selenium compounds regulate the delivery of zinc from metallothioneine to zinc enzymes. To date, however, there have been no studies on the selenium and zinc status of the Mongolian population. Study objective. The objective of this study was to assess the biochemical indicators of micronutrient deficiency among 6-36 months old children. Subjects and methods. This cross-sectional study was conducted in four districts of Ulaanbaatar city and in centers of Bulgan, Bayanhongor, Dornod and Khovd aimags and included 243 (122 male and 121 female) apparently healthy children aged 6 to 36 months. Hemoglobin analysis was performed using a hemoglobinometer Hemocue AB, serum ferritin was analyzed by enzyme immunoassay technology, serum retinol by high-pressure liquid chromatography, serum zinc and selenium were analyzed by atomic absorption spectrophotometry and serum 25(OH)D analysis was performed using radioimmuno assay procedure. Results. Mean hemoglobin, serum ferritin, folate, 25(OH)D, retinol, zinc and selenium concentrations in children from Ulaanbaatar city and aimag centers were determined. Age-group differences for the means were significant for hemoglobin, serum ferritin, serum folate (p=0.001)and serum zinc(p=0.01). The differences between Ulaanbaatar and the aimag centers were also significant for hemoglobin, serum ferritin, serum zinc (p=0.05) and serum folate (p=0.001). 24.3% of the children were anemic. The prevalence of anemia was greater among the children in the aimag centers than in Ulaanbaatar city and in younger children than in the oldest age group. The prevalence of iron deficiency anemia was 15.3% and was independent of setting but was lowest in the oldest children aged 24 to 36 months. Of all the surveyed children, only 3.7% had low level of serum folate. The overall prevalence of low serum retinol levels indicative of vitamin A deficiency was 33.7%, with no differences by setting or age group. 74.7% of the children had low serum zinc concentrations. There was no significant difference in the prevalence between children living in Ulaanbaatar city and the aimag centers, or among the three age groups of children in either setting. The overall prevalence of low serum selenium concentrations was 57.7%, with no differences in the prevalence by setting or age-group. The prevalence of low serum levels of 25(OH)D was 61% and was highest among the children aged 6 to 12 months of Ulaanbaatar city. Conclusion: 1. Zinc deficiency had the highest prevalence (74.7%) among the surveyed children, followed by low serum selenium levels (57.7%). 2. 36% of the children were at risk of two and 64% of more than two coexisting micronutrient deficiencies. 3. There is a need for multi-micronutrient programs that take into account the potential interactions of micronutrients instead of the present single micronutrient based interventions on-going in Mongolia.