If the allotment of shelf space at local pharmacies is any indication, an increasing number of Canadians are depending on pills to complete their nutritional intake. The vitamin and mineral industry in North America has become a multibillion-dollar industry, but, alarmingly, the knowledge of what these supplements do and how much we really need them has not kept pace with consumption.

Dietary intake has not been monitored consistently in Canada until recently, and as a result, the dietitian community has little understanding of the role supplements should play in the lives of Canadians.

Susan Whiting, professor and head of nutrition and dietetics at the University of Saskatchewan in Saskatoon, hopes to change this by conducting a study to find out just what part supplements play — and should be playing — in our lives.

“People need to realize how much we don’t know,” Whiting says. “It seems like we have a good understanding of what all these vitamins and minerals do. But in some cases, we still lack research on how much we need of some of these and, also, how harmful they are.”

For individuals who follow the Canada Food Guide and eat a mixed diet of both plant and animal sources, Whiting says, the need for mineral and vitamin supplements should be quite low until after the age of 50.

But the varied eating habits of people today do not always reflect the ideal balanced diet. For example, a low intake of fruits and vegetables, or preferences such as vegetarianism, restrict vitamin and mineral intake.

“Within every age group, you probably have situations in which someone may need a supplement,” Whiting says. “A young woman who is a vegetarian may be well advised to take an iron supplement, as meat is a good source of iron and that woman is abstaining from it. But I wouldn’t say every young woman needs iron.”

While the need for supplements is determined by assessing individual diets, some common needs arise among particular demographics. Researchers have discovered the recommended amount of vitamin D is not enough, and most people should supplement it. Also, extra folic acid for pregnant women has been proven to reduce the risk of certain birth defects. People over age 50 are usually advised to take extra calcium, vitamin D and vitamin B12 — nutrients that seem to be more difficult to absorb naturally as we age.

Yet finding out just how much to supplement is tricky. The recommended intake and maximum intake of each supplement is difficult to determine and, despite some credible sources, much conflicting information exists in books and online.

Health professionals, however, have easy access to correct information, and should be the first contact in determining whether supplements are needed. A private, paid consultation with a dietitian may be needed to determine which supplements are needed and how much is healthy.

“My concern is that when people self-diagnose, if they don’t know what they currently are eating, then they don’t know what they need,” Whiting cautions. “So, people shouldn’t just go and take a supplement. They need to know what they are currently getting and what the gap is. If you take too much, it can be harmful.”

Side effects of improper nutritional supplementing can range from minor annoyances such as diarrhea caused by too much vitamin C to serious nerve damage from too much vitamin B6, or liver damage from too much niacin or vitamin A.

“We’re still not at a level of really good understanding of that stuff,” Whiting says. “Then you add to that mix all the new herbals people are taking — we have very little understanding of those. They’re sold in nice packages, but that doesn’t mean we know what they do.”

The hormones and herbal products that North Americans ingest, in addition to nutritional supplements, are usually attempts to increase longevity or avoid prescription drugs.

Some believe, for example, that human growth hormone increases fitness and retards the aging process.

But Phil Chilibeck, associate professor of kinesiology at the University of Saskatchewan, says there is no evidence to support this claim. Instead of increasing quality and length of life, HGH has been linked to heart disease and may also stimulate cancer growth.

Experimenting with herbals can also be dangerous. “If you go out and start taking a certain remedy like crazy, it could have side effects just as a drug could have,” Chilibeck says. “People need to exercise caution, and it’s probably best to exercise moderation.”

@page_break@Although hormones and herbal remedies are largely uncharted territory, Whiting hopes that her current work will soon answer some pressing questions about Canadians’ nutritional intake.

Her research, which is co-commissioned by the Canadian Foundation for Dietetic Research and Dietitians of Canada, will provide a current picture of vitamin and mineral use by Canadians, and should be released in the spring of 2008. IE