Under-fours may be handed vitamin D supplements amid government concerns over the return of rickets, a disease common during Victorian times but virtually eradicated during the Second World War.
About 10 million people across England may be low on the vitamin, which also risks leaving them prone to weak bones and tenderness.
Chief medical officer Dame Sally Davies is said to be concerned at the number of children suffering from the condition.
Alastair Sutcliffe, a leading expert on vitamin D deficiency and a consultant paediatrician at University College London Hospitals, told the Sunday Times: “Nothing is free but the cost of the ill-effects of deficiency, such as rickets and anaemia, from families not providing children with these supplements is greater for the NHS.”
He said deficiencies are probably due to a trend of children spending more time indoors.
According to figures by Vitamin D Mission, published in October, the average British toddler is only getting 27 per cent of the daily dietary vitamin D recommendation.
Vitamin D is mostly obtained from the action of sunlight on the skin.
Dietary sources include oily fish, such as salmon, sardines and mackerel, eggs, and fortified spreads and breakfast cereals.
Some pregnant women and children under four already qualify for free vitamins under the Government’s Healthy Start programme.
The National Institute for Health and Care Excellent (Nice) is carrying out an analysis of the Healthy Start vitamin programme to determine whether it would be cost-effective to move from the current targeted approach to a universal offering.
Scientific studies have previously shown that children growing up in colder places struggle to produce Vitimin D.
The Nice final report is due to be given its formal publication in June of this year.