Iodine supplements during pregnancy
Iodine is a trace element absolutely necessary for the body’s thyroid hormones production. The estimated minimum daily requirements of iodine for a woman is 150 mcg/d. Pregnant women, however, need an average of 200-220 mcg/d. Iodine supplements (sodium or potassium), present in commercial preparations of common salt –in correct concentrations 20-40 ppm– provide an adequate support to meet the minimum daily requirements in a diet. (Huckleberry Y et al. Handbook of Nonprescription Drugs. 13th ed. Washington: American Pharmaceutical Association, 2002. p. 457, 481).
During pregnancy it is important to maintain an adequate supply of iodine, as its deficit in the diet can cause changes in the synthesis of thyroid hormones in mother and fetus, as well as fetal brain development and growth retardation. At the other extreme, high iodine intake during pregnancy may block the fetal thyroid function, causing hypothyroidism and goiter. (Haddow JE et al. N Eng J Med 1999; 341(8): 549-55; Delange F et al. Drug Saf 2000; 22(2): 89-95).
In our environment, within the Pregnancy, Childhood and Puerperium Care Process of the Regional Ministry of Health of the Andalusian Government, a supplementation of 150 mcg/d of iodine is recommended during pregnancy and breastfeeding. (Embarazo, Parto y Puerperio. Proceso Asistencial Integrado. 2ª ed. Sevilla: Consejería de Salud. 2005. p. 110). Organisms such as WHO and UNICEF also agree on this recommendation (WHO et al. Assessment of the iodine deficiency disorders and monitoring their elimination. Geneva: WHO. 2001).
In conclusion, iodine requirements increase during pregnancy, as it occurs with other trace elements. Although it is increasingly common to use iodized salt, it does not seem sufficient in order to achieve the minimum recommended requirements, and, therefore, iodine supplementation is recommended during pregnancy and breastfeeding.