This study evaluated efficacy of iodized salt for mothers and their six-month-old infants' thyroid hormones and visual information processing. Half of the participants received 450 g iodized salt for the household each week, while the other half received 225 ug iodine daily as a potassium iodide capsule.

Iodine is essential for the synthesis of thyroid hormones, and thyroid hormones regulate the metabolic processes of most cells and play important roles in human growth and development. Iodine deficiency disorders can have serious consequences on brain and physical development. In neonates iodine deficiency and hence insufficient supply of thyroid hormones could cause neonatal goiter, neonatal hypothyroidism, and endemic mental retardation.

Iodine deficiency disorders can be prevented and controlled by providing iodine and iodine can be provided in different ways. However, the United Nations Children's Fund and the World Health Organization jointly recommended salt iodization where iodized salt is accessible. Iodized salt is a safe, cost effective and sustainable strategy to ensure sufficient intake of iodine by all individuals and to improve maternal and infant health. However, although the effect of iodine on human health is well established efficacy of iodized salt has not been studied.

Inclusion Criteria:

• The women must be lactating and must have an infant less than or equal to one week old.
• Mothers had to volunteer to participate in the study.

Exclusion Criteria:

• Any hyperthyroidism symptoms manifested by nervousness, anxiety, heart palpitations, or rapid pulse.
• If infants had fever, cough or severe (>3/day) diarrhea
• Any allergic reaction such as acne, weakness, or foul breath