Iodine Deficiency in Pregnant Women
Barbara Lock, MDFebruary 27, 2009
Researchers at Boston University Medical Center found that only 51 percent of U.S. prenatal multivitamins contain iodine, which could result in iodine deficiency, the UPI reports. Iodine is found in seafood, including seaweed, and supplemented salt.
Iodine deficiency in pregnant women can lead to hypothyroidism, and cretinism in the child. Cretinism is a syndrome of significantly impaired physical, mental and cognitive growth. According to Hong et al in a report in the journal Seminars in Perinatology, there is good reason to speculate that cretinism and cerebral palsy may overlap. The term 'cretin' is derived from the French word for "Christian," and first referred to affected people who lived in the Alps.
Hypothyroidism from iodine deficiency is most commonly found in people who live in landlocked countries where seafood is inaccessible. Severe hypothyroidism in an adult can lead to formation of a goiter, or an enlarged thyroid gland, in the front of the neck. Adults with hypothyroidism, even without a visible goiter, become tired easily, are frequently cold, may have constipation, and can have thickened, hairless skin. In developed countries, infants with genetic hypothyroidism or hypothyroidism due to iodine deficiency are usually identified at birth, due to widespread and required antenatal testing. While ongoing medical care can prevent further damage from hypothyroidism in the infant, it is unclear whether pre-natal injury to the fetus from hypothyroidism will reverse.
Pregnant women should get 200 to 250 micrograms of iodine per day, through diet or supplementation, to prevent cretinism, according to a Joint Statement from the World Health Organization and the United Nations Children's Fund. While supplementation of salt with Iodine has been considered to be a sufficient public health intervention to prevent hypothyroidism, hypothyroidism due to iodine deficiency can still occur. According to a study by Marchioni et al in the journal Nutrition, 92% of pregnant women studied in Italy, a coastal country in which iodized salt is available, had inadequate iodine intake, whereas only 4% of non-pregnant women were deficient.
The higher iodine requirement by pregnant women may in part explain the findings of a Cochrane Review by Angermayr et al that while iodine supplementation programs in iodine-deficient regions is a good means of preventing goiter and improving iodine status in children, a clear improvement in mental and physical status of children was not seen. This lack of clear effect may be due to the presence of additional nutritional or environmental factors which affect development, such as iron deficiency.
The use of dual-fortified salt, or salt fortified with both iodine and iron, is described in the American Journal of Clinical Nutrition by Zimmerman et al. In a randomized controlled trial performed in Africa, they found that 39% of people given dual-fortified salt had goiter after 10 months, compared to 51% who were given salt that was fortified with iodine alone. This is an absolute risk reduction of 12%. This means that 8 people need to be provided with dual-fortified salt over iodized salt alone in a goiter-endemic area to prevent one case of severe hypothyroidism. Those are pretty good numbers. An alternative might be to provide cast-iron cookware, which increases the amount of iron in foods cooked in it.
Please read our legal disclaimer.
Write a comment
- Required fields are marked with *.
Posts: 2
Reply #2 on : Wed March 10, 2010, 14:53:35
Posts: 2
Reply #1 on : Wed April 29, 2009, 10:30:35
Bookmark with:
What are these?