Vitamins: Beware marketing hype

In your quest for good health, are you buying an increasing assortment of nutritional preparations? You’re not alone if it seems the supplement aisle at your pharmacy or health food store is getting more of your attention and health-care dollars these days. Canadians are now spending billions of dollars each year on dietary supplements.

But who benefits most from supplements, the people who consume them or the supplement manufacturers? The variety of nutritional preparations that have no proven health advantages is rapidly expanding. A glance at supplement labels will reveal names of added phytochemicals — disease-fighting compounds from plant foods – such as lycopene or flavonoids, many of which have not been shown to provide health perks on their own.

High doses of vitamins or minerals or various phytochemicals (or phytonutrients, as they’re also known) may be added as a marketing ploy to boost sales. And in some cases, there may be the potential for harm.

As nutritional scientists shift from studying how various nutrients act in avoiding deficiency conditions and instead examine their role in disease prevention, supplements are becoming brk sellers, especially for those in the 50-plus age group. For example, avoiding scurvy due to a vitamin C deficiency is no longer a hot issue. Researchers are instead delving into the effect of this nutrient in decreasing the risk of illnesses such as heart disease, stroke and certain cancers.

Because of this research, health professionals are more likely to recommend a multi-vitamin and mineral preparation, especially for those over the age of 50. Shortfalls can occur at this age because of increased nutrient needs or a potential decrease in absorption of certain nutrients, such as vitamin B12. But recommendations for purchasing products can range from those based on science to those that seem to originate in science fiction. 

Evaluating the claims
And it appears that the number of supplements with scant science behind them is increasing dramatically. An aging population, large profits and easy access to information via computer all contribute to potential purchases and scams. Surf the web and you’ll come across all kinds of information about supplements, some reliable but most is not. Websites will trumpet the benefits of various supplements by quoting extensive scientific research, but all too often the research is not valid and hasn’t been published in peer-reviewed journals where scientists familiar with the subject evaluate the study design and whether there is any bias involved.  

Many of these sites actually sell supplements or provide a link to a sales site. Be a savvy surfer by looking for reliable sources of information. Check out the Tufts University Nutrition Navigato at for an online rating and review guide of websites offering nutrition information. It not only directs you to sources of information but its rating and evaluation system also lets you know whether the sites are trustworthy.

Another website useful for sorting through the fact from fiction is Look for the article “Twenty-Five Ways to Spot Quacks and Vitamin Pushers” by Stephen Barrett, M.D. a well-known quackbuster.  

Next page: When to be suspicious

When seeking the right supplement, look for those that provide the Dietary Reference Intake (DRI) for your health status and age. The amounts for various nutrients have been determined by expert scientists assembled by the national Food and Nutrition Board of the Institute of Medicine in the United States.

Because of the boom in supplement use, these new DRIs now incorporate the daily recommended intake along with the Tolerable Upper Intake, the highest level that likely won’t pose a health risk. But there are also nutrients where there simply is not enough research to set levels and for those nutrients, the board has come up with a level called an “adequate” intake.

When to be suspicious
One of the telltale signs when spotting a vitamin pusher, according to Barrett, is their claim that the daily recommended intakes are set too low and that only supplements can help you meet the true requirements. Or that you, for some reason, may need more and should purchase their supplement, almost as insurance. Other sales pitches to watch for are the claims that the product is “bio-available,” meaning that your body will better utilize it. While some are better absorbed, the bio-available claim is often not worth the much higher price.

When it comes to supplements, research shows that more is not always better. When you look at amounts of nutrients that can’t be consumed in a normal day through food choices, then the supplement should be considered a drug. And drugs, whether pharmaceutical or nutritional, need to be tested.

When you’re confronted by a sales pitch, here’s some food for thought.

Vitamin C
This nutrient has long been thought of as an antioxidant, a substance that can protect against oxidation – think of an apple turning brown when exposed to air. Oxidative damage is linked to a higher risk of various illnesses including artery disease, certain cancers and Alzheimer’s. But it’s vitamin C-rich foods that are known to possess the most antioxidant power. High doses of the vitamin in supplement form may act as pro-oxidants in some people. Antioxidants counter oxidation while pro-oxidants speed up the damage.

Vitamin C supplements have been previously thought of as having potentially adverse effects in men with higher levels of iron in their blood. A recent study, though, published in the November 2004 issue of the American Journal of Clinical Nutrition, provides reasons for women to also proceed with caution. The scientists followed more than 1,900 postmenopausal women with diabetes over a 15-year period and found that those who took higher doses of vitamin C – 300 milligrams daily or more – were more likely to die from heart disease and stroke than those who took lower doses of vitamin C supplements or those who obtained all their vitamin C from food. It’s just a preliminary study but it may be a smart idea hold off on high doses until more is known. Keep eating your fruits and veggies, though.

Vitamin E
The reputation of this vitamin as a supplement has plummeted over the past few years. Preliminary studies showed it to be a possible superstar in preventing heart disease and stroke. But in clinical studies, where similar groups of people take the particular compound or a placebo, vitamin E has not fared well.

Scientists at Johns Hopkins University recently conducted an analysis of 19 clinical trials involving vitamin E supplements and found that doses of 400 International Units (IU) and higher were associated with a substantially increased risk of death. The same was not shown for supplements containing only 100 IU. The verdict’s not yet in, however, as there have been criticisms that some of the studies were carried out on people with chronic diseases and this may have skewed the results. 

The bottom line
Some high dose supplements may interact with various medications so it’s wise to discuss their use with a knowledgeable health care provider such as a pharmacist, physician or registered dietitian. And when you’re choosing a supplement, keep the definition of the term in mind. As much as supplement makers would like you to believe otherwise, a supplement is an addition to your food choices, not a replacement.