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Canwest News Service
With Health Canada poised to let food makers fortify a wide range of new products with vitamins and other nutrients, a group of leading emergency-department doctors is calling for vitamins to be treated like over-the-counter drugs because of their potentially dangerous side effects.
The physicians from children's hospitals in British Columbia, Alberta and Ontario also recommend that vitamin A no longer be allowed as an ingredient in multivitamins, citing evidence that it can cause birth defects in high doses.
The researchers stress that vitamins are generally safe and healthy when consumed appropriately. But with many Canadians convinced that taking large quantities of certain supplements can stave off various medical problems, the doctors caution that the public needs to know more about the downsides of high doses or improper chronic use.
Those effects range from liver damage caused by too much vitamin A to hardening of the arteries linked to vitamin C, the physicians outline in a paper just published in The Annals of Pharmacotherapy. Some can also interact riskily with other drugs, undermining blood-clotting ability, for instance, when combined with the popular painkiller Ibuprofen.
"We don't want to wait for something bad to happen," said Dr. Ran Goldman, head of emergency at the B.C. Children's Hospital and the study's lead author.
The doctors take aim as well at a proposal being considered by Health Canada to give food manufacturers freedom to fortify a wide range of products, including snack foods and pop, with vitamins and other nutrients. A department official reiterated in a recent letter that the government is moving toward the change.
The idea is "unacceptable," given the already high consumption of vitamins in society, the emergency physicians say.
Health Canada, though, says that it has serious concerns about their study and how it portrays regulation of vitamins. In fact, the nutrients are covered by the government's new natural-health products rules, and they require substances to undergo assessment before being approved and to carry detailed side-effect information, the department said in an email response to questions.
The doctors suggest the five-year-old natural-health regulations are not appropriately stringent for products
such as vitamins. Heather Boon, a pharmacy professor at the University
of Toronto who studies natural-health
products, said that is not true, though she noted that spotty application of the regulations so far means safety labelling of vitamins now varies from product to product.
"The problem is that people think vitamins and they automatically think 'They must be good for you, and more must be better,' and that's when people get into trouble," she said. "
We need to be conscious that if you take too much, you could run into trouble."
Carl Carter, regulatory affairs chief at the Canadian Health Food Association, said consumers should be better informed about vitamins — because of their benefits.
"Canadians are underexposed to vitamin D, particularly in the winter months," he said. "From a safety point of view, there could be as much as a 70% reduction in the risk of cancer through the appropriate use of vitamin D."
The study cites evidence that as many as a third of Americans use vitamins, suggesting that the figures are similar in Canada.
A survey by the same group in Toronto found that 32% of children who showed up at an emergency department had taken vitamins in the previous three months, though parents often fail to mention such use.
The doctors outline five vitamins they feel should be treated like drugs– A, E, D, folic acid and niacin — based on safety research produced over the past 40 years.
Large doses of niacin, for instance, can cause digestive symptoms ranging from nausea to peptic ulcers, the paper notes.
Many scientists are now recommending people in northern climates boost their consumption of vitamin D– naturally produced when sunshine strikes the skin — as evidence mounts that it helps prevent various cancers and other illness.
Excessive amounts of it, though, can cause problems including kidney damage and anemia, the study says.
National Post, with files
tblackwell@nationalpost.com
