The human body requires a number of vitamins and minerals to function properly. Examples include vitamin A, which is required by the retina in the eye; vitamin D, which is required for maintaining healthy bones, and vitamin E, which helps form red blood cells. A diet lacking enough essential vitamins is likely to result in vitamin deficiency syndromes. Scurvy, rickets and beriberi are examples of such syndromes. Eating a healthy, balanced diet typically provides enough vitamins for the body’s needs. Some people like to take multivitamins to ensure that they receive their required amounts.