Across the state, grade four students and their parents were being asked to volunteer with an at-home urine sampling test.

The survey is part of five-yearly research, run by the Menzies Institute for Medical Research and contracted by the state government.

Researcher Dr Kristen Hynes encouraged people to take part, and said Tasmania continues to lead the country with iodine intake.

"We need to make sure that every day we're eating foods with iodine because the thyroid gland which produces hormones from the iodine needs to replace it," she said.

"It's really important for growing children that they have this, because it's vital for brain development, and especially also for pregnant women and women who are breast feeding because they need more in their diet.

"Some of the research we've done has shown that women who have inadequate iodine during pregnancy, their children are performing worse in literacy all the way through their schooling."

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The main sources in Tasmania of iodine are dairy milk, bread and seafood.

Samples taken from students set to inform future research and initiatives to promote iodine intake.

"We need to get about 400 kids to take part across the state, that will give us a representative sample," she said.

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"What we hope to find is that the levels have not changed - five years ago and 10 years ago, the public health initiatives that were put in place ... that saw things go from being mild deficiency in the population to having adequate or optimal iodine.

"We need to keep monitoring because things change, people's diets change, industry practices change, so we don't want to find ourselves back in a situation like we were."

Selected schools will send home information with students in coming weeks, with results expected at the end of the year.

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