Despite recommendations that all pregnant and lactating women in Australia should take supplements containing 150 µg iodine per day [21
], 40% of pregnant women and 55% of lactating women in the current study were not receiving iodine supplementation. However, the use of supplements containing iodine had increased from 20% to 60% in pregnant women, pre and post fortification, an important improvement. Prior to 2009, the major commercial brand of pregnancy supplements in Australia did not contain iodine [30
] which explained our earlier finding of only 20% uptake in pregnant women [13
]. The reformulation of pregnancy supplements to include appropriate levels of iodine reflects a positive move by industry and should be further encouraged until all supplements for pregnant women contain appropriate levels of nutrients, including iodine.
We have previously reported data from the current study sample that 1–2 years following introduction of the mandatory iodine fortification programme of salt used in bread-making in Australia, median urinary iodine concentrations of both pregnant and lactating women indicated sufficiency only in those who were taking iodine-containing supplements [23
Since the early 1990s, there has been little public debate in Australia around issues of nutrient fortification of foodstuffs in the food supply [31
] and this may contribute to lack of awareness of such public health activities. To the authors’ knowledge, no public or professional education initiatives directed to the importance of iodine during pregnancy and lactation have been conducted following the introduction of mandatory iodine fortification or the release of the NHMRC position statement on the need for iodine supplementation for pregnant and lactating women, at least not in the area of New South Wales where this work was conducted. Our data were the first to report that Australian women have a low level of knowledge regarding the detrimental outcomes of iodine deficiency during pregnancy [13
], and this has not changed after fortification. Indeed, few women are aware that bread is required by law to be fortified with iodine.
Many women incorrectly identified neural tube defects and weak bones and teeth to be related to iodine deficiency, which suggests general confusion between the function of iodine with other micronutrients. The simultaneous implementation of both folic acid and iodine fortification of bread in Australia [20
] may have contributed to this consumer misunderstanding.
Women’s access to information about iodine in pregnancy and lactation remains inadequate post-fortification. Although the percentage of women who believed they had received adequate information about iodine had doubled since the 2008 survey [13
], it was still far lower than information received regarding other health and nutrition priorities in pregnancy. In response to the findings of our 2008 study in pregnant women, there has been a change in clinical practice in the public antenatal facility that was sampled, whereby all pregnant women should now receive an information sheet about iodine at their first clinic visit. Despite this, most women remained uninformed about the need to ensure an adequate iodine intake during pregnancy and lactation and only approximately half (49%) of the pregnant women reported receiving verbal or written information from a healthcare professional. Many women receive early antenatal care from their general practitioners and may not attend antenatal services until later in their pregnancy. In either situation, limited importance may be given to verbal communication from the health care practitioner, as reported by the women, compared with distribution of printed materials alone.
There was also confusion about food sources of iodine, with many women identifying vegetables and meat as good sources. Although the majority of women identified fish and seafood as being rich sources of iodine, few were consuming seafood regularly, as evidenced by its low contribution to total iodine intake (3%–8%). Concerns regarding mercury contamination in seafood and the risk of listeriosis and other food poisoning agents may be deterring pregnant women from consuming larger amounts of seafood, and leading to the omission of this important nutrient-rich food group [32
]. Further qualitative research regarding factors that influence fish intake in pregnancy is warranted, to better understand the way in which pregnant women assimilate the various nutrition-related messages that are provided simultaneously. Indeed, participants were better informed regarding iron, folate, calcium, Listeria
and food poisoning, and were more confident that they could make informed decisions regarding these issues, compared to food choices about iodine. Information on iodine is provided to pregnant women attending public antenatal clinics in the state in which the present surveys were completed (i.e.
, New South Wales) [34
] however the information is provided in a general booklet that also includes information on folic acid, food safety and mercury in fish. Materials are also available on various government and non-governmental websites [35
Our studies confirm that dairy foods remain the major contributor to total iodine intake, due to their high frequency of intake, even despite changes in dairy industry sanitation practices in Australia, whereby iodophors have been replaced with other sanitizing agents [18
]. This study shows intakes increased by approximately 35 μg/day after the iodisation of bread, which is in line with the estimated increase of +46 μg/day in adults, that was modelled by Food Standards Australia New Zealand (FSANZ) in their assessment report [17
This paper reports on findings relating to studies of women in one region of New South Wales therefore generalizability to other states and geographical areas, such as inland locations, cannot be made. Self report bias of participants completing the questionnaire and food frequency questionnaire cannot be ruled out. However, the use of standardized instruments across surveys, together with a lack of change in knowledge and awareness over time, supports our conclusion that women are no better informed about iodine following introduction of one of only three mandatory nutrient fortification programmes in the country introduced for public health outcomes, the others being thiamin (1991) and folic acid (2009) also added to bread.