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

Abstract

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.

THERAPY OF ENDOCRINE DISEASE: Impact of iodine supplementation in mild-to-moderate iodine deficiency: systematic review and meta-analysis

“…However, a recent WHO forum has indicated that strategies to reduce salt intake and increase iodine fortification should not necessarily be contradictory and such strategies could support each other (69). Alternative strategies such as iodisation of bread as used in Australia and New Zealand (70,71,72) have been largely unexplored in the UK. However, supplementary iodine intake may still be indicated in addition to food fortification in vulnerable sub-populations such as pregnant women and children (71,72).…”

“…Alternative strategies such as iodisation of bread as used in Australia and New Zealand (70,71,72) have been largely unexplored in the UK. However, supplementary iodine intake may still be indicated in addition to food fortification in vulnerable sub-populations such as pregnant women and children (71,72). Routine prenatal iodine supplementation is recommended by professional bodies in North America (73) and Europe (74) but it is unlikely that this is systematically adhered to in many European countries where gestational iodine status remains inadequate (75,76,77).…”

The Analysis of Domestic and International Policy of Food Fortification With Trace Elements and Salt Iodization

“…2673 детей 8−11 лет из 12 регионов на основании сниженной йодурии (норма более 100 мкг/л) установлена легкая сте-пень йодного дефицита, а в ряде районов Волго-градской, Астраханской и Нижегородской обла-стей медиана йодурии у школьников соответство-вала тяжелому йодному дефициту (Дедов и др., 2008). Йодурия у 61,7% из 115 обследованных де-тей (11±1 год), проживающих в интернатах Твер-ской области, также соответствовала легкому йодному дефициту (Clifton et al, 2013).…”

“…В Австралии после введения в 2009 г. обяза-тельного обогащения йодом хлеба путем заме-ны обычной соли на йодированную увеличило медиану йодоурии у беременных женщин с 68 до 84 мкг/л (р = 0,011), однако не позволило полно-стью ликвидировать недостаточность йода (Clifton et al, 2013). После введения в 2000 г. в Дании обязательного обогащения йодом используемой для выпечки хлеба соли на уровне 13 мкг/г в 2004−2005 гг.…”

Iodine Deficiency in Pregnant Women Pre- and Post-Mandatory Iodine Fortification in Australia - An Epidemiological Review

“…Although fortification has had favourable results in adults and children, several studies have demonstrated ongoing iodine deficiency in pregnant and breastfeeding women despite improvements in iodine status in the post-mandatory fortification period [37][38][39]. Indeed, the FSANZ predicted that most pregnant women would remain iodine deficient [12].…”