There was an interesting article in this month’s Pediatrics which discussed the importance of iodine supplementation in pregnancy and lactation. Iodine is typically found in the diet as iodide and is necessary to produce thyroid hormone. Thyroid hormone is crucial for brain development in children. However, the article states that even mild iodine deficiency in children can also affect cognitive development.
Because salt in processed foods is typically non-iodized, both the American Thyroid Association and the National Academy of Sciences recommend the iodide intake of breast feeding women to be 290 ug of iodide per day. This generally requires an additional supplement of 150 ug iodide per day. Yet, it is estimated that only 15-20% are taking any supplement that contains iodide.
The take-home recommendation from the article is that pregnant and breastfeeding women (and thus their infants) may be iodine deficient. “Breastfeeding mothers should take a supplement that contains at least 150 ug of iodide and use iodized table salt (combined iodide intake should be between 290-1100 ug of iodide per day).”
The article also states that breastfeeding mothers who are Vegan or does not consume dairy or fish should consider having their urine tested for iodine deficiency.
Environmental exposures that can interfere with iodine utilization include excess dietary nitrate (common pollutant of private well water). Therefore well water should be checked annually. Thiocyanate from tobacco smoke is also a potent iodine inhibitor therefore pregnant women should not smoke or be exposed to second hand smoke.
Finally, consistency in labeling is being addressed by the FDA who is encouraging use of only potassium iodide. It is important to note that a supplement must contain at least 197 ug of potassium iodide per dose to yield 150 ug of daily iodide supplementation.
Pediatrics Volume 133, Number 6, June 2014.