Vitamins are organic compound nutrients that the body needs in very little amounts. They are crucial for both health and development, as well as for disease prevention and treatment. The majority of vitamins are not produced by the body and must be obtained from food or taken as supplements.  Generally speaking, a balanced diet that includes enough fruit and vegetables will supply all the vitamins the body needs to remain at optimal health. However, using supplements may be necessary to assist the body during periods of stress, fatigue, illness or in other situations.