Iodine Inadequacy may be Complicating Pregnancy Outcomes
Iodine deficiency in pregnancy is a leading cause of preventable mental retardation worldwide. It is estimated that 18 million infants are mentally impaired due to iodine deficiency. Two new papers examine iodine deficiency among pregnant women in Europe and the cost/benefit ratio of iodine supplementation.
The World Health Organization defines iodine status using urinary concentrations, preferably 24 h collections, of 150-249 ng/ml for pregnant women. Iodine inadequacy is impacting pregnancies in the UK and Australia. Wei and colleagues report that 48.3% of pregnant women in Shanghai China are iodine deficient (urinary iodine concentration < 150 µg/g creatinine). The iodine content of household salt and multivitamin supplements were the primary determinants of status.
In many countries table salt is iodized for home and table use. Packaged foods can be fortified but most are not. Recommendations to decrease salt intake may be contributing to the re-emergence of iodine deficiency. If iodized salt was used in all food preparation, the World Health Organization estimated the cost would be 10 cents per person year.
The CDC’s Second Nutrition Report finds that American women 20-39y have the lowest urinary iodine status of all age groups. Iodine deficiency is the most prevalent micronutrient deficiency among adolescents and adults in the US.
The adverse effects of inadequate iodine status seems to be a universal problem.
Zimmerman MB, Gizak M, Abbott K, Andersson M, Lazarus JH. Iodine deficiency in pregnant women in Europe. 2015 Lancet Diab Endocrinol doi: 10.1016/S2213-8587(15)00263-6
Monahan M, Boelaert K, Jolly K, Chan S, Barton P, Roberts TE. Costs and benefits of iodine supplementation for pregnant women in a mildly iodine-deficient population: a modelling analysis. 2015 Lancet Diab Endocrinol doi: 10.1016/S2213-8587(15)00212-0
Charlton K, Skeaff S. Iodine fortification: why, when, what, how, and who? 2011 Curr Opin Clin Nutr Metab Care doi: 10.1097/MCO.0b013e32834b2b30
Horton S. The economics of food fortification. 2006 J Nutr 136(4):1068-1071
Murphy RA, Ciappio ED, Bird JK. Lower prevalence of vitamin and mineral deficiencies among adolescent users of full spectrum multivitamin/mineral supplements. 2015 FASEB Abstract 250.4
Bird JK, Ciappio ED, Murphy RA. Adult full spectrum multivitamin/mineral supplement users have a lower prevalence of vitamin and mineral deficiencies. 2015 FASEB Abstract 586.2