During the period 1986-2003, the prevalence of anemia among children under five declined even though no supplementation program was implemented. It could only be speculated that the reduction of common infections due to effective implementation of primary health care programs,
deworming, and improved diets may have contributed to this improvement. Recent field intervention studies on micronutrients showed that iron deficiency only contributes 10-25% of anemia in Thailand.
33-35
Other factors,
namely, hemoglobinopathy and marginal vitamin A deficiency were also significantly associated with haemoglobin in children.
33