The policy is expected to prevent between 162 and 240 neural tube defects over 30 years, saving the country between $25 million and $47m in health, education and productivity costs in that time.
The Government will hand over about $1.6m for flour millers to cover the cost to buy and install equipment for the task.
In the meeting, fellow board member Johann Morreau said Thurston had been "New Zealand's primary advocate" for the introduction of folic acid to bread, describing his work "tireless".
Another member, Rob Vigor-Brown, said he saluted Thurston, saying it was work "for the kids".
Chairman Dr Jim Mather acknowledged Thurston's leadership in the area, which he called an "important issue for our tamariki and future generations".
"He toka tū moana. You are the rock in tumultuous seas and tremendous storms, to be able to withstand all the challenges over the years."
A five-line email from the DHB's Woman, Child and Family Service clinical director, Dr Stephen Bradley, to chief executive Nick Saville-Wood contains four exclamation marks, congratulating Thurston on a "lifetime of advocacy".
In his home in Rotorua's south on Friday afternoon, Thurston was less focused on taking the credit for himself, instead soberly recalling the trials, tribulation and exhaustive data- trawling over 40 years of campaigning.
He says shortly after Simon was born, Thurston discovered through his reading the discussion about a lack of folate in modern people of child-bearing age.
He connected with epidemiologists such as Dr Godfery Oakley in the US and Professor Fiona Stanley in Australia – both leading advocates for folic acid fortification of flour to prevent conditions such as spina bifida.
Since then Oakley had become "part of the family". Thurston said he'd just got off the phone with Stanley, who was "absolutely blown away" at the news.
Thurston is still on message though: folic acid is a soluble vitamin B that is non-toxic and any excess in the body will be excreted. It has significantly reduced brain, spine and spinal-cord birth defects in the many countries it has been implemented in, such as the US, Canada and Australia.
He's battle-worn from "last time" - in 2009, New Zealand and Australia agreed on mandatory folic acid fortification.
Lyall Thurston in 2007 shortly after the Helen Clark-led Labour Government committed to folic acid in bread. The decision was reversed in 2009 by the new National Government. Photo / Andrew Warner
But it wasn't to be. The National Government backed out of the decision following opposition from bakers and industry lobby groups.
"They were all about dismantling the 'nanny state of Helen Clark'."
Australia's rate of neural tube defects dropped by 14 per cent overall and 74 per cent for the indigenous population.
Thurston said Oakley told him to "just keep going and never lose sight of the prize".
"It was families like mine who kept pushing and knocking on doors."
Particularly the doors of MPs, Thurston says, which he believes made the difference. There had been opposition from the Greens about choice and "pure food", he says, but that has changed.
However, in that time, children had been "committed to wheelchairs" he says, and some children hadn't survived – something he described as "unforgivable".
He says those who opposed it had "blood on their hands".
Lyall Thurston says those who opposed the introduction of folic acid in bread 12 years ago had "blood on their hands". Photo / Andrew Warner
"It was a political decision [not] one based on science and research. The science has always been there."
Thurston says after about 40 years of campaigning he had mixed emotions at hearing the news, but elation was one of them.
"What a gift the New Zealand Government has given to babies yet to be born.
"But there's a sense of foreboding, we've been here before."
