There has been a marked increase in the number of children suffering from rickets because parents are putting too much sunscreen on them or keeping them indoors.
Rickets was common in the early 1900s but had almost disappeared from Britain.
However, a recent study carried out by Professor Nicholas Clarke, a consultant orthopaedic surgeon at Southampton General Hospital, found there were 185 cases in 2001 and that figure rose to 479 cases in 2009.
The data was from 42 Primary Care Trusts (PCTs) which responded to the survey.
Professor Clarke said: "I saw an infant a month ago who was referred to me because of delayed walking. The child was 15 months old and could not stand physically."
He acknowledges the balance parents have to strike, but lifestyle changes concern him greatly.
"It's very difficult for parents because they're encouraged to apply sunscreen because of the dermatological consequences of not.
"But it would seem that that excess is too much for bone health and vitamin D. They're shutting out the sunshine which is causing problems with bones.
"Similarly children and adolescents don't go out as much; there aren't as much school sports and when they do go out they tend to cover up."
A lack of exposure to sunlight can lead to a vitamin D deficiency, which causes the disease.
Vitamin D is known as the sunshine vitamin because our skin can produce it from the sun's ultra-violet light.
It helps control the amount of calcium we absorb and is important for the development of strong bones.
Without it rickets can develop which cause bones to soften and usually legs appear bowed.
Four-year-old Toby Ault from West Sussex was diagnosed with early onset of rickets nine months ago.
His mother, Kathryn, said: "He kept coming to me saying 'Mummy, Mummy, my legs hurt'."
When she took Toby to the family doctor, he suspected it was a vitamin D deficiency and a blood test confirmed it.
Kathryn continued: "It's shocking because it's such an old-fashioned disease, but it does make sense because we do drive a lot of places, so he's not really exposed as much as he perhaps should be.
"And you do slap sun cream all over your children because you're told to, that's drummed into you."