In an ideal world, your children's diet would include plenty of vegetables, fresh fruit and whole grains.
They would drink enough milk (or soy beverage) each day to cover their calcium needs, and they'd routinely choose nutritious snacks over junk food.
But the reality is that many Canadian kids eat a narrow range of healthy foods and don't meet the minimum recommendations of Canada's Food Guide. Many parents are left wondering whether their children should be taking a multivitamin supplement.
When you add up the obstacles that can prevent kids from getting enough nutrients - picky eating, food allergies, vegetarian diets, hectic schedules that leave little time for balanced meals - there can be an argument for adding a multivitamin to your child's daily routine.
Most experts contend that healthy children should be able to get all the vitamins and minerals they need from a balanced diet, but according to the 2004 Canadian Community Health Survey on nutrition, many kids get failing grades when it comes to following Canada's Food Guide.
Seven out of 10 children between 4 and 8 don't eat the recommended daily five servings of vegetables and fruit - a habit that's likely to shortchange their diet of folate (a B vitamin), vitamins C and A, potassium and magnesium.
The survey findings also suggest that children don't get enough calcium and vitamin D, key nutrients for building strong bones and teeth. More than one-third of children between 4 and 9 don't get the daily recommended two servings of milk products.
The statistics get worse as they get older: By ages 10 to 16, 61 per cent of boys and 83 per cent of girls don't get the recommended minimum three servings of milk a day.
Some children and teenagers will benefit from a daily supplement. If your child is a picky eater who does not eat at least one daily serving of meat and alternatives (poultry, fish, eggs, legumes, soy), a multivitamin with added iron is a good idea.
Kids who are allergic to certain foods may also benefit from a multivitamin.
Studies have shown that children with food allergies, particularly those with allergies to milk or multiple foods, are at increased risk of not meeting daily targets for calcium, vitamin D, vitamin E, riboflavin (B2) and niacin (B3).
Children who don't have regular exposure to sunlight, or don't drink at least two cups (500 millilitres) of vitamin D-fortified milk or soy milk daily, or who follow a vegetarian diet, should take a multivitamin with at least 200 IU (international units) of vitamin D.
In addition to vitamin D, vegetarian kids may not be getting all the vitamin B12, calcium, iron and zinc their growing bodies need. (That also applies to children who limit their calorie intake in an effort to stay slim.) There's some evidence to suggest that a multivitamin might do more than simply ensure that children get the nutrients missing from their diets.
A recent review of 13 studies investigating the influence of a multivitamin and mineral supplement on intelligence in children found that most studies reported a positive effect, especially in kids whose diets were low in vitamins and minerals.
According to psychologists at California State University, a daily vitamin supplement might also promote good behaviour in kids. In their study, researchers assigned groups of children, aged 6 to 12, to either a placebo pill or a daily vitamin and mineral tablet. After four months, those who did not get the extra nutrients needed twice as much discipline. It's thought that poor nutritional habits in children that lead to vitamin deficiencies can impair brain function and cause antisocial behaviour.
Children's multivitamins - formulated for kids aged 2 to 12 - differ from those of adults not only in their lower nutrient doses, but also in their form, ranging from chewable tablets to gummy bears to liquid drops. Some formulas contain vitamins only, usually vitamins A, D, E, C, B1, B2, B3, B6, B12 and folic acid. Others are fortified with iron (four or five milligrams) and some have added calcium (125 to 160 mg). Menstruating girls, vegetarians and children who don't like meat should choose a formula with iron.
Keep in mind that children's multivitamins labelled "complete" may not contain all vitamins and minerals important to a child's health. And that's okay, provided your child gets the rest from his or her diet. But if you're giving your child a one-a-day pill because his diet lacks iron or calcium, read labels to be sure you're buying what your child needs.
For older children, aged 9 to 13, daily calcium requirements (1,300 mg) translate into four milk product servings a day. One cup (250 ml) of milk or fortified soy beverage, 175 ml plain yogurt or 1½ ounces (45 grams) of cheese delivers roughly 300 milligrams of calcium. If your child's diet lacks calcium, he or she will need to take a separate calcium supplement. Older children can't rely on a multivitamin supplement to provide enough calcium because most brands contain no more than 160 mg of the mineral.
During the teen years, daily requirements for most vitamins and minerals increase to match - and in some cases exceed - adult levels. That's when they should switch to an adult formula.
While multivitamin supplements are generally safe for healthy children, they can be toxic if taken in large amounts. To prevent a young child from getting too much of any one nutrient, always choose a formula made for them. Treat multivitamins like any other medication: Keep them out of children's reach.
Multivitamins can't make up for a consistently poor diet that's high in fat and sodium and lacking in fruits and vegetables. So even if you give your children multivitamins, encourage them to eat a variety of healthy foods.
Leslie Beck is a registered dietitian and author of The No-Fail Diet (Penguin Group Canada, 2006). Visit her website at lesliebeck.com.