In healthy individuals, eating a balanced and healthy diet that follows Canada’s Food Guide recommendations is usually enough to ensure that vitamin and mineral needs are being met. People who do not follow these dietary recommendations, however, could benefit from vitamin and mineral supplements. But it is important to remember that a multivitamin cannot replace healthy eating: the human body does not assimilate the vitamins and minerals contained in these tablets the same way it processes those from food sources. In addition, while supplements can occasionally compensate for poor eating, they are not a long-term solution to replace fruit, vegetables, whole grains, dairy products and other nutrient-rich foods.
Vitamins and minerals are involved in almost all of the body’s processes. Even though only minute amounts of them are required on a daily basis, a vitamin or mineral deficiency can lead to a multitude of diseases. Conversely, a diet rich in nutrients could help keep the body at its healthiest.
The following is a brief overview of the properties attributed to some of the vitamins and minerals most commonly purchased by the general population.
Vitamin C
Of all the vitamins, vitamin C (also known as ascorbic acid) is by far the most popular. Nearly miraculous properties have been attributed to it. According to some, vitamin C can prevent or cure a wide array of health problems ranging from the common cold to cancer. This myth is probably the reason some people tend to overuse this vitamin. However, the only indication that is possibly justified for vitamin C is that it may slightly reduce the duration and symptoms of a cold. Research findings are contradictory when it comes to other indications, which include treating or preventing cardiovascular disease, cancer, cataracts, atherosclerosis, etc.
No consensus has yet been reached on daily vitamin C requirements. There is in fact significant controversy with regards to the ideal daily dose of this vitamin. It is generally accepted, however, that consuming five portions per day of fresh raw fruit and vegetables (e.g. oranges, raspberries, red peppers, lemon, grapefruit and tomatoes) is more than enough to meet our vitamin C requirements. In the Western world, it is extremely rare to see the symptoms of a vitamin C deficiency, which manifest as scurvy. Indeed, a dose as low as 10 mg per day is sufficient to keep teeth and gums healthy and to prevent scurvy.
Vitamin A
Vitamin A, also called beta-carotene or retinol, is another popular vitamin. Just like vitamin C, it has a reputation of being able to prevent or cure numerous ailments. Among other things, it is said to help prevent cancer, improve vision and make skin look younger.
It is in fact true that vitamin A is essential to good vision and that it helps keep teeth, skin and bones healthy. However, we can get all the vitamin A we need simply by eating a healthy diet. Excellent sources of vitamin A include sweet potatoes, carrots, mango, cantaloupe, apricots, meat and chicken liver.
Generally speaking, if you eat a balanced diet, vitamin A supplements are not necessary. In addition, excess vitamin A intake can have adverse effects. Researchers have recently noticed that a daily dose that is slightly higher than the daily requirements can cause a decrease in bone mass and even lead to osteoporosis. Furthermore, eating copious amounts of fruit and vegetables high in beta-carotene can give the skin an orangey tone. Excess vitamin A intake is also associated with foetal malformations, so women who are pregnant (or who wish to become so) should exercise special caution.
Vitamin E
Vitamin E, or tocopherol, is another vitamin with a multitude of purported virtues. Often due to its antioxidant properties, its use has been proposed for the prevention of various diseases, including heart disease and cancer. And yet, other than to treat rare cases of vitamin E deficiency, there is no recognized medical use for anything but the recommended daily dose.
Once again, as with vitamins A and C, a balanced diet is usually sufficient to meet daily vitamin E requirements. This vitamin is usually plentiful in high-fat foods. Excellent sources include nuts, seeds, vegetable oils and leafy green vegetables. Recent research, incidentally, has brought up concerns regarding vitamin E supplements, particularly when taken in high doses: some studies have noted elevated risks of bleeding, and a slight increase in the risk of death when all causes are taken into account. Caution is therefore recommended.
Other vitamins and minerals
In all, there are 13 essential vitamins, and they can be split into two groups, depending on whether they are more compatible with water or fats. Vitamins A, D, E and K are called fat-soluble vitamins, as they are stored in body fat. For this reason, consuming excesses of the vitamins in this group can lead to harmful effects, since they tend to accumulate in the body. B-complex vitamins (thiamine, riboflavin, niacin, pantothenic acid or B5, pyridoxine or B6, biotin, folic acid, B12) and vitamin C, on the other hand, are called water-soluble, since they have more affinity for water. They are therefore eliminated more quickly, through the kidneys. Every vitamin is essential to the proper functioning of the body, but daily requirements are amply met through a balanced diet.
The properties of the various minerals are not quite as well known as those of vitamins. The minerals include sodium, iron, calcium, zinc, chromium, phosphorus, magnesium, chlorine and iodine. Minerals have numerous therapeutic indications, and the many properties attributed to them vary from one mineral to the next. Although minimal daily mineral requirements have been established, we do not yet know at what dose toxic effects begin appearing, hence the importance of consuming them with caution. Once again, individuals who eat well do not need to worry about their mineral intake.
Do you need to take supplements?
Some people may need to take supplements in order to increase their vitamin and mineral intake. This is the case, for example, with pregnant women who require more folic acid, calcium and vitamin D. Elderly individuals who get very little sun exposure or who do not eat very much may also suffer from vitamin deficiencies and may benefit from taking a multivitamin. Alcoholic individuals often suffer from vitamin B complex deficiencies, especially when it comes to thiamine. Lastly, some smokers may have greater vitamin C requirements, but a glass of orange juice per day is enough to meet those needs.
In the case of healthy individuals, it is always preferable to improve the quality of our diet than to take a vitamin supplement, as foods provide other essential nutrients (e.g. fibre), which is not the case with multivitamins.
To find out more on the quality of your diet, speak to a dietician or to your healthcare professionals.