Campaign launched by health authorities to give vitamin D supplements to babies, writes CLAIRE O'CONNELL
IT’S A debilitating condition that was considered long gone. But in the early years of the 21st century, nutritional rickets has reared its head again in Ireland.
Its reappearance in a handful of young children has prompted a campaign in Ireland to give vitamin D supplements to babies in the first year, but at only half the daily dose recommended in North America.
Cases of nutritional rickets – a childhood condition caused by a severe lack of vitamin D in which the bones become deformed – were spotted by a group of dietitians working at maternity and paediatric hospitals in Dublin, says Dr Mary Flynn, chief specialist in public health nutrition at the Food Safety Authority of Ireland (FSAI).
More than 20 cases were detected in these hospitals over a few years, and Flynn was present at a meeting where the dietitians highlighted the re-emergence.
“It was very surprising,” she says. “They had never seen it before. There was no referral for nutritional rickets prior to the early 2000s.”
While the findings were not published in a peer-reviewed paper, the fact that any cases of rickets had been spotted was enough to constitute an early warning, according to Flynn.
“Rickets is always the tip of the iceberg in terms of actual nutritional deficiency, and when you start seeing cases of rickets you know there are a lot of cases you are missing,” she says.
The condition is also a canary in the coalmine for vitamin D deficiency in the wider population that may not be as severe, and that’s backed up by recent studies of nutritional status, according to Flynn.
“Virtually every study where they have taken blood to look at vitamin D status they have found levels of deficiency during the winter,” she says.
So why are we lacking the vitamin, and particularly in winter? A small number of foods contain vitamin D naturally, including oily fish, and some foods have the vitamin added by manufacturers.
And for the most part we make the vitamin ourselves through skin exposure to sunlight. It doesn’t take much, but due to our latitude, UVB light can be in short supply in Ireland, especially during the winter months, explains Flynn.
“Our Gulf stream makes us think we are not that far north at all but we are.”
The Health Service Executive has now started to roll out an information campaign, based on an FSAI report recommending that all babies up to 12 months, whether breastfed, formula fed or taking solid foods, be given 5 micrograms (200 international units) of a vitamin D-only supplement each day.
Yet this is against a backdrop of no published data on the current nutritional status for vitamin D in infants. Why do we not have those figures?
“It’s hard to get mothers to agree to having a blood sample pulled from a baby,” says Flynn. “And you didn’t need to go there. You don’t hold back on a public health recommendation that’s safe.”
In addition, the dose of 5 micrograms per day also appears low when compared to recommendations of 10 micrograms per day for infants in the US and Canada, where milk is fortified with vitamin D and many (in the US at least) live at more southerly and sunny latitudes than Ireland.
But Flynn argues for the safety and simplicity of the 5 microgram message.
“The 5 microgram dose is totally adequate,” she says, noting that because vitamin D is fat-soluble and we can store it, it is possible to overdose.
“We know that if every mother gave 5 micrograms every day, there wouldn’t be a problem.”
Other countries have had issues with putting out public health recommendations about vitamin D that are too complex, adds Flynn, and the guidance of 5 micrograms for all babies under a year, no matter how they are fed, is straight- forward.
She also notes that the current recommendation is an interim measure, and that more evidence would be needed before changing the dose.
“When you are giving a public health message out, you are giving it to everyone in the population and you have to be sure it’s of benefit to everybody and it’s not putting anybody at risk.”
Dr Mairead Kiely from the vitamin D research group in University College Cork has been involved in several studies of vitamin D levels in populations in Ireland, and she welcomes the new supplementation guidelines, but laments the lack of baseline data on infants.
“This new policy is wonderful and it’s being implemented in the hospitals, and it is being rolled out very effectively,” says Kiely, who is currently researching vitamin D levels for breastfeeding mothers.
“But unless we know what the baseline status is in the babies, they won’t know how effective the policy is and if it is going far enough. What we need is baseline data from a representative sample of babies from zero to 12 months.”
Meanwhile, paediatric specialist registrar Dr Aoife Carroll is carrying out a study of vitamin D status in children coming into Temple Street Children’s University Hospital.
“We have seen some babies come in who are on vitamin D, but there are a lot who are not, haven’t been told,” she says. “But there has been better awareness in the last couple of months.”
Her study is analysing vitamin D levels in mainly healthy children who present at the hospital for minor problems or elective procedures.
“The general idea is to determine the prevalence of vitamin D deficiency in Irish children and see whether children need to be taking supplements beyond a year of age,” she says.
