Should Iodine be a Nutrient of Concern?
Do you know your iodine status? I don’t. In fact, rarely do I even look for the iodine content of a food. For people living in regions where the iodine content of soils and ground water is low, consuming crops grown locally can lead to iodine deficiency. In fact, 26-70% of children living in the Great Lakes, Appalachians and Northwestern regions of the US were iodine deficient with clinically apparent goiters in the early 1900’s. Iodization of salt changed their lives and millions of others. However, salt iodization is only effective if people consume iodized salt.
Anaforoglu and colleagues studied 864 healthy pregnant women from an iodine deficient region of Turkey. 91% of the women were using iodized salt. Still, iodine deficiency was prevalent. Median urinary iodine concentrations were observed to decrease during the pregnancy.
Consumption of fortified foods has effectively reduced risk of nutrient deficiency diseases such as beriberi (thiamin), goiter (iodine), pellagra (niacin), and rickets (vitamin D). Although voluntary fortification of foods is sometimes perceived to contribute to excessive nutrient intakes above the upper limit (UL), adults never exceed the upper limit (UL) from food intake. In short, fortified foods are major contributors to nutrient intakes for everybody – children, adolescents, and adults.
Fortification practices can vary considerably between countries. Use of fortified products varies among individuals. Use of iodized salt varies among food manufacturers and restaurant owners. Although more than half of the table salt sold is iodized, with advice to limit the use of table salt, our iodine intake will be increasingly dependent upon the foods we choose to eat and the salt choice, iodized or non-iodized, of the food preparer.
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Leung AM, Braverman LE, Pearce EN. History of US iodine fortification and supplementation. 2012 Nutrients doi: 10.3390/nu41111740
Hennessy A, Walton J, Flynn A. The impact of voluntary food fortification on micronutrient intakes and status in European countries: A review. 2013 Proc Nutr Soc doi: 10.1017/S002966511300339X
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Murphy R, Ciappio E, Bird J. Lower prevalence of vitamin and mineral deficiencies among adolescent users of full spectrum multivitamin/multimineral supplements. 2015 FASEB J 29(1):250.4
Bird JK, Ciappio CD, Murphy RA. Adult full spectrum multivitamin/multimineral supplement users have a lower prevalence of vitamin and mineral deficiencies. 2015 FASEB J Abst #3587