Today I’m featuring an article written by fellow dietitian and mom, Valeria Mallett, RD who has a very informative facebook page, Yumm Little One.
What is iodine and why is it important for health?
Iodine is an essential mineral used by the body to produce thyroid hormones –triiodothyronine (T3) and thyroxine (T4). As a public health measure, iodine was added to table salt (as potassium iodine) to prevent dietary insufficiency of the population, as iodine is needed for the synthesis of thyroid hormone in the body and is critical for normal growth, development, and metabolism, especially in gestation. Historically, adding iodine to salt was an effective method to reduce goiter cases around the world. Iodine deficiency is still present in some parts of the globe and is the leading preventable cause of mental retardation, as well as other preventable problems such as maternal and fetal goiter, cretinism, intellectual impairments, neonatal hypothyroidism, and increased pregnancy loss and infant loss.
How much do people need?
As Registered Dietitians, we can educate individuals about the importance of iodine and its recommendations. Though is often rare to see a severe iodine deficiency in the United States, Americans should be concerned with mild-to-moderate deficiencies of iodine as it poses risks to the health of mother (goiter) and child’s intelligence, psychological profile, and ADHD disorders. Iodine levels in United States remain adequate for the majority of the population; however, the 2009-2010 NHANES shows that future mothers are not meeting the daily recommendation of iodine –which is 150-249 micrograms/L, and there is a trend seen in NHANES surveys concerning decreasing optimal iodine intake. The daily recommendations are as follows:
1 to 8 years old: 90 micrograms
9 to 13 years old: 120 micrograms
14 years and older: 150 micrograms
Pregnant: 220 micrograms
Lactating: 290 micrograms
Thyroid hormones increase nearly 50% during pregnancy, and there are also other theories about why the intake of iodine (measured by Urinary Iodine concentation) has been dropping for this vulnerable population: soil type, change in sanitizing solution in dairy production (although milk is still a very good source of iodine), increased consumption of processed foods that utilize non-iodized salt to optimize flavor, and use of alternative non-iodized salts such as sea salt, kosher, and Himalayan.
Which foods are iodine-rich?
Seaweed (such as kelp, nori, kombu, and wakame), Cod fish, shrimp, dairy products, iodized salt, eggs, lima beans as well as fruits and veggies (depending on soil), grain products, and dietary supplements*.
*although iodine levels vary in MVI/prenatal vitamins.
Iodized salt is still a very good source of iodine and should not be neglected in healthy individuals. The salt provides 400 mcg of iodine per teaspoon, and although we stress the importance of keeping sodium intake at minimum, opting for iodized salt when used–even in small amounts, is beneficial to the health of individuals, preventing deficiencies and health problems in mothers and children.
References available on request.