Concerns over vitamin D deficiency -
Government guidelines recommend some groups, including the under-fives, should take a daily supplement.
However, recent research found that many parents and health professionals were unaware of the advice.
There has been an increase in childhood rickets over the past 15 years.
According to Dr Benjamin Jacobs, from the Royal National Orthopaedic Hospital, links to heart disease and some cancers are also being investigated.
The consultant paediatrician told BBC Breakfast that the hospital saw about one severe case a month of rickets - softening of bones through lack of vitamin D in childhood.
He said: "There are many other children who have less severe problems - muscle weakness, delay in walking, bone pains - and research indicates that in many parts of the country the majority of children have a low level of vitamin D."
The Feeding for Life Foundation report, published in October last year, suggested one in four toddlers in the UK is vitamin D deficient.
However, this may be an underestimate as only vitamin D from food was included, and not any vitamin D obtained through sun exposure.
Vitamin D supplements are recommended for all people at risk of a deficiency, including all pregnant and breastfeeding women, children under five years old, people aged over 65, and people at risk of not getting enough exposure to sunlight.
Vitamin D is mainly obtained from sunlight. However, too much sun exposure increases the risk of skin cancer.
According to one recent study, nearly three-quarters of parents and more than half of health professionals are unaware of the recommendations.
The Department of Health has asked the Scientific Advisory Committee on Nutrition to review the issue of current dietary recommendations on vitamin D.
Dame Sally Davies: "We know a significant proportion of people in the UK probably have inadequate levels of vitamin D in their blood. People at risk of vitamin D deficiency, including pregnant women and children under five, are already advised to take daily supplements.
Free supplements
"Our experts are clear - low levels of vitamin D can increase the risk of poor bone health, including rickets in young children.
"Many health professionals such as midwives, GPs and nurses give advice on supplements, and it is crucial they continue to offer this advice as part of routine consultations and ensure disadvantaged families have access to free vitamin supplements through our Healthy Start scheme.
"It is important to raise awareness of this issue, and I will be contacting health professionals on the need to prescribe and recommend vitamin D supplements to at-risk groups."
It has long been known that vitamin D prevents rickets and children were once given food supplements like cod liver oil.
However, this practice was stopped in the 1950s because it was thought unnecessary.
In the last 10 years, doctors have been seeing more cases of vitamin D deficiency, leading to a debate over the use of food supplements and concern that many medical staff are unaware of the problem.
