Widespread iodine deficiency among pregnant women. Adequate iodine intake is necessary to produce thyroid hormone, which is vital for pregnant women and for newborns for brain and cognitive development. Iodine deficiency increased from the 1970s to the 1990s because of the increased consumption of processed foods, which are prepared with noniodized salt. The American Academy of Pediatrics has issued a policy statement advising breastfeeding mothers to take a supplement that includes at least 150 micrograms of potassium iodide and to use iodized table salt. They should avoid nitrates, not smoke, and avoid second-hand smoke because thiocyanate, found in tobacco smoke, and nitrates can lower iodide concentrations within the thyroid gland and the mother's milk. The statement appears in the June Pediatrics.