Open Access Open Badges Research

The impact of iodine supplementation and bread fortification on urinary iodine concentrations in a mildly iodine deficient population of pregnant women in South Australia

Vicki L Clifton16*, Nicolette A Hodyl1, Paul A Fogarty2, David J Torpy3, Rachel Roberts2, Ted Nettelbeck2, Gary Ma45 and Basil Hetzel1

Author affiliations

1 Robinson Institute, University of Adelaide, Adelaide, SA, Australia

2 School of Psychology, University of Adelaide, Adelaide, SA, Australia

3 Department of Endocrinology, University of Adelaide, Adelaide, SA, Australia

4 Department of Medicine, University of Western Sydney, Campbelltown, NSW, Australia

5 International Council for Control of Iodine Deficiency Disorders Global Network (ICCIDD), Westmead Hospital, Westmead, NSW, Australia

6 Robinson Institute, Lyell McEwin Hospital, Haydown Rd, Elizabeth Vale, SA, 5112, Australia

For all author emails, please log on.

Citation and License

Nutrition Journal 2013, 12:32  doi:10.1186/1475-2891-12-32

Published: 15 March 2013


Mild iodine deficiency during pregnancy can have significant effects on fetal development and future cognitive function. The purpose of this study was to characterise the iodine status of South Australian women during pregnancy and relate it to the use of iodine-containing multivitamins. The impact of fortification of bread with iodized salt was also assessed. Women (n = 196) were recruited prospectively at the beginning of pregnancy and urine collected at 12, 18, 30, 36 weeks gestation and 6 months postpartum. The use of a multivitamin supplement was recorded at each visit. Spot urinary iodine concentrations (UIC) were assessed. Median UICs were within the mildly deficient range in women not taking supplements (<90 μg/L). Among the women taking iodine-containing multivitamins UICs were within WHO recommendations (150–249 μg/L) for sufficiency and showed an increasing trend through gestation. The fortification of bread with iodized salt increased the median UIC from 68 μg/L to 84 μg/L (p = .011) which was still in the deficient range. Pregnant women in this region of Australia were unlikely to reach recommended iodine levels without an iodine supplement, even after the mandatory iodine supplementation of bread was instituted in October 2009.

Iodine; Pregnancy; Urine; Supplements