Research indicates that most of the vitamins you get from the food you eat are better than those contained in pills. Even though vitamins in supplements are synthesised to the exact chemical composition of naturally-occurring vitamins, they still don’t seem to work as well.
The main exception to this is folate. The synthetic form (in a supplement or fortified food) is actually better absorbed by the body than folate from food sources.
Food is a complex source of vitamins, minerals and phytochemicals (plant chemicals), which all work together. Supplements tend to work in isolation. Research has shown that a food component that has a particular effect on the body may not have the same effect when it is isolated and taken as a supplement. This could be because the vitamins and minerals in foods are also influenced by other components of the food, not just the ‘active ingredient’.
Phytochemicals are an important component of food and are thought to reduce the incidence of heart disease and some cancers. Supplements do not provide the benefits of phytochemicals and other components found in food. Taking vitamin and mineral supplements is no substitute for a healthy diet.