Protein, fats and carbohydrates are classified as macronutrients as we eat them in large amounts. Vitamins are also classified into two groups – water soluble and fat soluble - and we obtain them by eating the plants and animals that make them.
 
Water-soluble vitamins – are not stored in the body but are quickly and easily lost, for example Vitamin C. For this reason, we need these vitamins every day.
 
Fat-soluble vitamins – are stored in the body, mainly in the fat cells and liver, for example Vitamin D. Taking large amounts on a long-term basis is not always recommended.
 
Vitamins function principally as coenzymes (with enzymes) for numerous metabolic and chemical reactions within the body. Without them, normal bodily processes could not occur. Most of them cannot be made in the body, except for some of the B Vitamins, which can be made by the beneficial bacteria normally present in our intestines. Vitamins are not part of our body tissues but are essential for growth, health and vitality. They are also useful to aid digestion, elimination and resistance to disease. Therefore, we cannot live on vitamins; we need food to provide our energy and also to help the absorption of any vitamin supplements that we take. However, without them normal bodily processes simply wouldn’t occur.