Iodine Supplementation in Pregnancy in an Iodine-Deficient Region: A Cross-Sectional Survey.

Iodine deficiency is a common problem in pregnant women and may have implications for maternal and child health. Iodine supplementation during pregnancy has been recommended by several scientific societies. We undertook a cross-sectional survey to assess the efficacy of these recommendations in a European iodine-deficient region. Urinary iodine concentrations (UIC) were determined in pregnant women before (n = 203) and after (n = 136) the implementation of guidelines for iodine supplementation in pregnancy. Iodine supplementation (200 µg/day) reduced the proportion of pregnant women with severe iodine deficiency (37.4% to 18.0%, p = 0.0002). The median UIC increased from 67.6 µg/L to 106.8 µg/L but remained below the recommended target level (>150 µg/L) for pregnant women. In conclusion, iodine supplementation in pregnant women improved iodine status in this iodine-deficient region but was insufficient to achieve recommended iodine levels in pregnancy. Additional measures, such as the adjustment of the dose or timing of supplementation, or universal salt iodization, may be needed.

[Iodine and thyroid: what a clinic should know]. / Iodo e tiróide: o que o clínico deve saber.

The World Health Organization considers iodine deficiency as a major worldwide cause of mental and development diseases, estimating that about 13% of the world population is affected by diseases caused by iodine deficiency. Iodine is a trace element necessary for the synthesis of thyroid hormones which, since it cannot be formed by the organism, must be taken regularly with food. Fish and shellfish are generally a good source, because the ocean contains a considerable amount of iodine. On the contrary, plants which grow in iodine-deficient soils are poor in this element, as well as meat and other animal products fed in plants low in iodine. Salt is the best way for iodine supplementation. Cooking the food with iodized salt is a desirable practice because it guarantees the presence of this element. There are also other methods to provide iodine to the general population, such as adding iodine to drinking water or taking supplements of iodine. In pregnancy is recommended iodine supplementation, except in patients with known thyroid disorders. Iodine is an essential component of thyroid hormones (T4 and T3). Inadequate iodine intake leads to inadequate thyroid hormone production. The most important consequences of iodine deficiency, in the general population are goiter and hypothyroidism, and in the severe cases, mental retardation, cretinism and increased neo-natal and infant mortality. The International Council for the Control of Iodine Deficiency Disorders (ICCIDD) formed in 1985, with the only aim of achieving optimal iodine nutrition in the world, in cooperation with UNICEF and WHO. In Portugal, recent studies show significant deficiencies in pregnancy and The Portuguese Society of Endocrinology Diabetes and Metabolism, in partnership with General Directorate of Health, proposed an iodine supplementation during pregnancy with 150-200µg/day.