Vitamins, minerals and other nutritional supplements all comprise of substances which occur naturally in our food and are vital for our health - hence the word vitamins. Many nutritionists will differ on the extent to which they use and recommend supplements, however all would agree that supplements are both useful in preventing deficiency and attaining optimum health and also in the treatment and prevention of disease.
Despite the great importance of these nutrients, quality food comes first. Buy the best quality food you can afford (i.e. organic). If you are eating a balanced diet (which few of us are) you are likely to be getting most of the vitamins you need. However because of soil depletion, you may not be getting enough minerals. Even the USDA (the most conservative of nutritional organisations) states that each person should take a daily multivitamin/mineral supplement. I would add to that most people also benefit from taking an omega-3 supplement and this nutrient is very often missing in our diet. People who need to take extra care to supplement effectively include stressed individuals, pregnant and nursing mothers, the elderly, anyone who is ill or has recently been ill, women who take the pill, menopausal women, anyone on drugs (prescription included) and adolecents. In fact, anyone going through changes in life should pay attention to their changing needs.
Most people find the array of supplements confusing, especially when looking at the RDA's or recommended daily allowance of each nutrient. Some supplements contain 100% of RDA's and other makes can contain up to 1000%. Let's look at what RDA's are according to the CDAFN who create them: RDA's are 'to be adequate to meet the known nutritional needs of practically all healthy persons.' Unfortunately this one size fits all approach leaves out many many people. As stated above there are many times of increased need where the RDA's are simply inadequate. Furthermore very few people are truly healthy. The RDA's should be looked on as minimum levels to prevent disease, which says nothing about amounts needed for optimum health. More unfortunately is that the majority of people do not even meet the minimum amounts of the RDA's.
Vitamins and other supplements can help us to acheive higher energy levels, a general feeling of well being and to prevent many health problems. They can also be used in combination with diet to treat many illnesses with little or no side effects. It's best to consult with a nutritionist about your specific needs.