The Department of Health calls for vitamin D supplement for young children, writes Gerry Byrne
ALL CHILDREN up to 12 months should receive a daily 5mg vitamin D supplement, the Department of Health has told the HSE following a major departmental policy review.
Alarm bells were rung last year in a Food Safety Authority of Ireland (FSAI) study by nutritional and medical experts which warned most Irish children were receiving less than the recommended daily dose of vitamin D, especially in winter.
The report strongly recommended that the Department of Health make vitamin D supplements a national priority for young children.
The FSAI study in turn was provoked by the discovery of 10 cases of rickets among Irish-born children, a finding which one of the report's authors said, "may have been the tip of the iceberg".
Rickets is caused by lack of vitamin D and leads to softening of children's bones and skeletal deformities. It was thought to have been eradicated in Ireland decades ago. Even more cases have come to light since the report was published.
Most vitamin D is produced by the action of sunshine on the skin but Irish sunshine levels between October and March are insufficient. Skin cancer warnings have also led more people to avoid direct sunlight so even in summer many people do not get enough sun exposure.
Use of a factor 15 sunscreen can reduce vitamin D production by 99 per cent, according to a study by Prof Michael Holick of Boston University Medical Center, who has described vitamin D deficiency as an international "pandemic".
However, the FSAI is not recommending that young babies be exposed to additional sunshine. Only a handful of foods such as oily fish, liver and eggs provide vitamin D so if these foods are not regularly consumed supplements are essential, says Dr Mary Flynn, chairwoman of the FSAI study group which produced the report.
The FSAI will now prepare recommendations for vitamin D levels in other sections of the population, especially women of childbearing age and the elderly. Babies born to mothers with vitamin D deficiencies are most at risk.
Some of the recent cases of rickets were in babies born to immigrant mothers with dark skins which can produce as little as 1 per cent the vitamin D of fair skins. Some were also born to Muslim women who followed strict religious observance of covering up most of the body.
Vitamin D deficiency is a leading cause of osteoporosis or brittle bone disease in the elderly where complications arising from fractures are a major cause of death. Currently international recommended doses of vitamin D are designed to prevent rickets and osteoporosis.
But studies comparing illnesses in sunny areas of the US with northern states and Canada (which has similar winter sunshine to Ireland) are discovering the rate of many diseases rises the further north one moves, leading some researchers to suspect vitamin D may play a greater role in health than previously recognised.
Not only can the elderly benefit. Research in University College Cork (UCC) showed bone mineralisation in girls improved significantly when they were given vitamin D supplements although Kevin Cashman, professor of food and health at UCC, says further work is needed.
Nutritionists and infant health experts have warmly welcomed the department's new guidance on vitamin D but some have questioned why it took so long since the report was issued in March 2007.
This recommendation means a careful balancing act for the FSAI study group and the department, explains Flynn, who is chief nutritional specialist at the FSAI.
"Mothers' milk is not very rich in vitamin D while it is added to formula for bottle-fed infants but we didn't want to provoke a swing away from breast- feeding which is still far more beneficial in almost every respect," she says.
Flynn adds that her group was also anxious to ensure that people didn't simply put young infants in more sun, which could have led to other problems. They also wanted to ensure the vitamin D supplement would be in the correct format.
At the time Flynn's report was submitted to the department, only one approved infant vitamin supplement contained vitamin D. However, it also contained vitamin A which can be toxic in excess and is already added to infant formula, so her group was reluctant to promote anything that could lead to over-consumption. Two preparations suited for infants containing only vitamin D have been approved since Flynn's report was published and these will be recommended.
"You don't idly recommend a population-wide supplement," says Dr Phillip Crowley, deputy medical officer at the Department of Health. "We took some time to reconsider the evidence, take soundings in the nutritional community and consult academics. We believe the recommendation is proportionate and safe."
Further studies of vitamin D levels in the Irish population are under way at UCC. In one study, funded by the UK Food Standards Agency, Cashman's department is attempting to decide the minimum vitamin D levels needed to prevent bone deterioration, or osteomalacia, in adults.
"The existing threshold only copes with more severe deterioration like rickets and osteoporosis. We are trying to see if we need to raise that threshold to take other diseases into account," Cashman says.
A further study is to assess the impact of vitamin D on the general health of the population.