Low income families across the UK already receive free vitamin pills
Vitamin pills could be free to all pregnant and breast-feeding women and young children across Wales, if a pilot scheme proves successful.
Currently, low-income families across the UK get free vitamins and vouchers for milk, fruit and vegetables.
Under the pilot scheme in Cardiff, vitamins will be free at health centres and given out by health visitors.
First Minister Carwyn Jones said the aim was to "give children the best start in life."
The scheme, which will cost £53,000 for the year, will be launched at the Ely and Caerau Centre, in Cardiff.
Attending the launch, Health minister Edwina Hart is expected to say: "These vitamins are needed for normal healthy growth and development."
The pilot will look at how best to distribute the vitamins to ensure as many people as possible can take advantage of them.
The findings will be reviewed after a year and if successful could be rolled out across Wales.
Outlining the scheme, the Welsh Assembly Government said that while a healthy diet would provide most of the vitamins needed, the free pills could help avoid vitamin deficiency illnesses, such as rickets.
The pills will be available free to all children in Cardiff up to four years old. Half of all children under five are reported to not have enough vitamin A in their diet.
Cardiff mother-of-three Emma Holmes said: "I'll definitely be taking advantage of the free vitamins for my youngest two children.
"Children need extra vitamins. I hope that mothers don't think they can replace a healthy diet with vitamin pills."
She added: "When I was pregnant I did not receive much information about healthy eating so it is good move to provide vitamins and diet information to mothers to be."
Helen Nicholls, community dietetic clinical lead and spokesperson for the British Dietetic Association, said the scheme was "a great step forward, ensuring that more people in Wales who need the vitamins will have access to them".