TITLE:
Iodine and Selenium Intake in a Sample of Women of Childbearing Age in Palmerston North, New Zealand after Mandatory Fortification of Bread with Iodised Salt
AUTHORS:
Nurul Husna Shukri, Jane Coad, Janet Weber, Ying Jin, Louise Brough
KEYWORDS:
Iodine; Selenium; Iodine Intake; Iodine Fortification; Iodised Salt
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.5 No.4,
February
11,
2014
ABSTRACT: Iodine deficiency is a worldwide public health
problem, which has long been observed in many parts of the world, including New
Zealand (NZ). The aim of this study was to assess iodine and selenium intake
among women of childbearing age in Palmerston North, New Zealand post mandatory
fortification of bread with iodised salt. Fifty women of childbearing age
completed a researcher-led questionnaire, including a semi-quantitative food frequency
questionnaire. Iodine and selenium were analysed in 24-hour urine samples. The
median urinary iodine concentration (UIC) was 65 μg/l with 30% below 50 μg/l; representing
mild iodine deficiency according to the World Health Organization. The
estimated median daily iodine intake (130 μg/day) was higher than the Estimated
Average Requirement (100 μg/day) and higher than seen in women prior to
fortification. The median excretion of selenium (32 μg/day) was slightly above
level suggested as adequate (30 μg/day) and estimated median intake (57 μg/day)
was higher than Estimated Average Requirement (50 μg/day). Selenium and iodine
excretion were significantly correlated (Spearman’s rank order; r(50) = 0.547, p 0.001). The major contributors to iodine intake
were milk (36%), bread (25%) and fish/seafood (15%). Participants had a mean
intake of 2.5 slices of bread/day, which contributed approximately 14 to 20 μg
of iodine. The majority of participants (74%) had iodised salt at home, but
less than half (48%) used iodised salt exclusively. In conclusion, despite the
mandatory fortification of bread with iodised salt in NZ, UIC of the study
population indicates iodine deficiency although their estimated dietary intakes
appear adequate. It is essential that government initiatives to improve iodine
status are evaluated for their efficacy.