A study of over 200 kids aged eight to fifteen in Saskatoon revealed that 36 per cent take vitamin or mineral supplements. However, only 14 per cent consistently use the same supplement throughout the year. Beta-carotene may have been the rage last month. Now zinc's hot. Adolescence is a time to experiment, and the multi-billion-dollar supplement industry is ready to supply their desires.
Teens who eat the number of servings recommended in Canada's Food Guide don't need vitamin and mineral supplements. But a daily supplement containing 100 per cent or less of the RNI of vitamins and minerals is usually safe. If your teen's meals are particularly erratic, it may even do a little good, but it won't substitute for the hundreds of nutrients supplied by a balanced diet of real foods.
Keep an eye on what they take
It's when kids self-prescribe individual vitamins that they can get into trouble. Supplements of a single nutrient may interfere with the absorption of other nutrients. For example, if he takes large doses of zinc over a prolonged period of time, your son could become deficient in iron and copper. As a general rule, the water-soluble vitamins B and C can be taken without major health hazards because you excrete the excess in your urine. But no vitamins, even the water-soluble ones, are safe in excess.
Help your teen determine if the dosage she's taking is within healthy limits. Ask her to consider consulting your doctor or a dietitian at the public health department. Diet books and infomercials offer a lot of contradictory and inaccurate information, so she needs help in selecting information from reputable sources. If your daughter has thrown caution to the wind and is consuming a cocktail of supplements, it's time to intervene-her health is at risk. Of particular concern are mega-doses (more than five times the recommended adult dose) of the following nutrients:
Vitamin A At 25,000 International Units (IU) a day, vitamin A can cause serious liver damage, hair loss, and bone and joint pain. If there's a chance your daughter may be or could become pregnant, more than 10,000 IU increases the risk of birth defects.
Vitamin D Prolonged use of 2,000 IU of vitamin D a day can cause nausea, high blood pressure, and kidney damage.
Niacin At 2,000 mg a day, niacin can cause an irregular heartbeat and liver damage. However, some people experience headaches, flushing, cramps, and nausea with just 50 mg a day.
Selenium Over 150 mcg a day of this antioxidant mineral may cause baldness and nail and tooth loss.
