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Take your vitamins? Or not?

Conflicting studies confuse the public; experts offer some safety tips on supplements

By: Shamona Harnett

Posted: 10/25/2011 6:40 AM | Comments: 0

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Be vigilant with vitamins

Not sure how and what vitamins/supplements to take?

Here are some tips from the experts:

Keep it simple. The more ingredients there are in a supplement combo, the more chance that one of them will not be the right amount, says Tod Cooperman, president of Consumerlab.com, a company that tests supplements and publishes ratings.

Consider a supplement combo tailored to your gender and age, the Office of Dietary Supplements suggests. Multivitamins often contain little iron, and ones for seniors give more calcium and vitamin D than products aimed at younger adults.

Take vitamin D with a meal containing fat; this will help with its absorption, according to some research.

Watch out for vitamin K; it promotes clotting and can interfere with common heart medicines and blood thinners such as warfarin, sold as Coumadin and other brands.

Current and former smokers are advised to avoid multivitamins with lots of beta-carotene or vitamin A; two studies have tied them to increased risk of lung cancer.

For cancer patients, "vitamins C and E might reduce the effectiveness of certain types of chemotherapy," says Jody Engel, a nutritionist with Office of Dietary Supplements.

If you're having surgery, talk to your doctor about what supplements you're taking. The doctor will probably advise you to stop taking all supplements, since some can thin the blood and lead to bleeding.

Consider that many foods are already fortified with vitamins and minerals.

Try to get your nutrients from whole foods as often as possible. "It's virtually impossible to overdose on the nutrients in food," says David Schardt, a nutritionist at the consumer group Center for Science in the Public Interest.

If you're going to take a multivitamin plus additional supplements, make sure you talk to your doctor and do thorough research by examining studies about the effects of the vitamin.

Calculate just how much of a particular vitamin you're taking and check with your doctor to make sure this amount is safe.

Fat soluble vitamins can be toxic in high doses since they can be stored your fat for long periods. Keep this in mind when taking vitamin A, vitamin K, vitamin D and vitamin E.

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If you've been wondering whether or not you should toss your vitamin supplements in the garbage, you're not alone.

The public's confusion comes after news suggesting vitamin and mineral supplements are linked to early death and/or disease. The headlines are a result of a couple of studies released earlier this month. One survey of nearly 40,000 women published in the Archives of Internal Medicine found a slightly higher risk of death among those taking vitamin and mineral supplements.

Another study -- this one published in the Journal of the American Medical Association -- found that men who took 400 IU of Vitamin E had a 17 per cent greater chance of developing prostate cancer within five years.

This follows research claiming that vitamins actually raise life expectancy.

"That's what I find frustrating. Consumers are getting bombarded with messages. One week, coffee kills you. The next week coffee will save you," says Prof. Jim House, head of the University of Manitoba's human nutritional sciences department. "It's really challenging to come up with clear messaging around something as complex as nutrition and the foods that we consume."

According to the Canadian Institutes of Health Research 2005 statistics, 57 per cent of Canadians use vitamin supplements. Meanwhile, in the last half of 2005 and the early part of 2006, Canadians spent $7.84 billion on alternative medicine and services.

House says rather than panic about each seemingly negative finding, consumers need to look past the headlines and put each nutrition study into context. That often means examining the facts of each one closely, even reading the actual journal article itself.

The women's vitamin study, for example, was large scale, but only looked at women over 60. Right away, there's a concern, says House. As well, the study was observational and relied on self-reported data, which, obviously, isn't always reliable.

He also notes the actual relationship between vitamin usage and mortality in the women's study was actually quite small and was mainly found only when the numbers were adjusted "using an approved statistical technique." This took into account certain factors such as age, education, place of residence, diabetes status, blood pressure and smoking status.

"A big question: Why just those factors?" asks House. "I almost call it torturing the data."

Most reports didn't mention that the women's vitamin study found that vitamin D and calcium each appeared to have increased life expectancy.

Also skewing the results could be what House calls the 'sick user effect.'

"Basically, it's when people get a diagnosis of something and then they start taking vitamins," he says. "In all likelihood they are the ones who are probably going to die sooner because they have been diagnosed with a disease."

-- With files from Associated Press

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