Risk of zinc, iodine and other micronutrient deficiencies among school children in North East Thailand

Introduction: Micronutrient deficiencies during childhood can contribute to impairments in growth, immune competence, and mental and physical development, and the coexistence of several such deficiencies can adversely affect the efficacy of single micronutrient interventions. Objective: To assess the prevalence of zinc and iodine deficiency and their interrelationships with vitamin A deficiency and anemia and associations with socio-economic status, hemoglobin type, and anthropometry in a cross-sectional study. Setting: A total of 10 primary schools in North East Thailand. Methods: Non-fasting venipuncture blood samples and casual urine samples were collected from 567 children aged 6-13 years. Anthropometric measures and serum zinc, albumin, C-reactive protein and urinary iodine, are reported here and integrated with published data on vitamin A, anemia, and socio-economic status. Results: Of the children, 57% had low serum zinc and 83% had urinary iodine levels below the 100 mu g/l cutoff. Suboptimal serum zinc and urinary iodine concentrations may result from low intakes of zinc and iodized salt. Significant risk factors for low serum zinc were serum retinol < 1.05 mmol/l and being male. Those for urinary iodine < 100 mu g/l were height-for-age score > median and being female. For serum retinol < 1.05 mu mol/l, risk factors were low hemoglobin, low serum zinc, and < 9 years, and for low hemoglobin indicative of anemia risk factors were < 9 years, AE hemoglobinopathy, and serum retinol < 1.05 mu mol/l. Of the children, 60% were at risk of two or more coexisting micronutrient deficiencies, most commonly suboptimal urinary iodine and low serum zinc. Conclusion: The findings emphasize the need for multimicronutrient interventions in North East Thailand.