Footballer Marcus Rashford has called on health professionals to boost awareness of the Healthy Start scheme, which helps pregnant women and struggling families with young children buy basic food.
NHS data shows, in the four weeks to July 18, 2,467 people in Doncaster were receiving vouchers from the scheme, which are worth between £4.25 and £8.50 a week and can be spent on healthy fruit and vegetables, milk or baby formula.
But they represent just 59 per cent of those identified as eligible for the benefit, with the figures showing there may be another 1,712 families in the area missing out on valuable support.
Across England and Wales, just over half (59 per cent) of those eligible for the scheme were receiving the support they were entitled to during the period.
In a letter published in the British Medical Journal, England player and campaigner Mr Rashford, a member of the Child Food Poverty Taskforce, urged health professionals to spread the word about the scheme.
The letter said: "The scheme has proven benefits in improving access to healthy food for pregnant women and children under the age of four.
"More than 40 per cent of those eligible for the vouchers are still not registered for the scheme and I'm confident that the majority of these parents can be found in communities just like mine, where I grew up – no internet, no high street, no word of mouth.
"Long term, sustainable change can only come when communities work towards a common goal.
"No child deserves to be starting life 20 yards behind any other from the day they are born, just because of where they are born and the circumstances they are born into."
The Food Foundation says a lack of awareness, complexities with the application process and a "postcode lottery" of public health promotion have contributed to a stark disparity in uptake, which varies between 42 per cent and 71 per cent across local authorities, excluding the City of London where just five people were eligible.
A spokesman for the charity, which recently found that 14 per cent of UK families with children had experienced food insecurity in the six months to September 2020, said uptake was "worryingly low" and meant a significant number of families were missing out on support.
Joining Marcus Rashford in calling on health care professionals to play "a vital role in actively encouraging awareness in communities", he added: "Many simply haven't heard of the scheme.
"And then of course there is the issue of stigma, many young families just feel embarrassed about being perceived to rely on benefits or hand-outs."
A spokesperson for the Department of Health and Social Care said the Government is committed to ensuring every child receives the best possible start in life.
He added an online application form is being developed as an alternative to the current postal system and will be introduced along with a payment card to replace paper vouchers.