Oral Presentation Joint Annual Scientific Meeting of the Nutrition Society of NZ and the Nutrition Society of Australia

The fortification of bread with iodised salt eradicates iodine deficiency in New Zealand schoolchildren (267)

Emma Jones 1 , Briar Davies 1 , Rochelle Hawkins 1 , Eva Meiklejohn 1 , Rachael McLean 1 , Sheila Skeaff 1
  1. University of Otago, Dunedin, New Zealand

Background/Aim: Iodine deficiency re-emerged in New Zealand (NZ) in the 1990s, prompting the mandatory fortification of bread with iodised salt from 2009. This study aimed to determine if the fortification of bread has improved the iodine status of NZ schoolchildren.

Methods: This was a cross-sectional survey of 8-10 year old children living in Auckland and Christchurch conducted from March-May 2015. Children provided a spot urine sample for the determination of urinary iodine concentration (UIC) and completed a questionnaire ascertaining socio-demographic characteristics that also included an iodine-specific food frequency questionnaire (FFQ). The FFQ was used to estimate iodine intake from main food sources including bread and iodised salt.

Results: The median UIC for all children (n=415) was 116 μg/L (females: 107 μg/L; males: 131 μg/L), indicative of adequate iodine status according to WHO (i.e. 100 to 199 μg/L). There were signficant differences in UIC by ethnicity (p<0.001) and sex (p=0.006) but not iodised salt use (p=0.890). The mean estimated iodine intake including iodised salt was 101 μg/d (females: 101 μg/d; males: 102 μg/d), with 23% of the children having an iodine intake below the EAR. Bread contributed 51% of total iodine intake in the food-only model, providing a mean intake of 35 μg/day.

Conclusions: These results are comparable to a similar study conducted in 2011 of Dunedin and Wellington children. Together they provide convincing evidence that iodine deficiency has been eradicated in NZ schoolchildren since the mandatory fortification of bread with iodised salt.

Funding Source: University of Otago Research Grant