Vitamins are nutrients that are found in the foods we eat. They’re needed for functions such as growth, metabolism, and nervous system activities. Often, a health-promoting diet can provide all. One type comes from animal sources of food. It helps you see at night, make red blood cells, and fight off infections. The other type is in plant foods. It helps prevent damage to cells and an eye. This article explains what vitamins are, what they do, and which foods are good sources. Follow the links in blue below for more information about each vitamin. Vitamins are usually designated by selected letters of the alphabet, as in vitamin D or vitamin C, though they are also designated by chemical names, such as niacin and folic acid. Biochemists traditionally separate them into two groups, the water-soluble vitamins and the fat-soluble vitamins. A vitamin is a chemical compound that is needed in small amounts for the human body to work correctly. They include Vitamin A, many B vitamins (like B 1, B 2, B 3, B 6, and B 12), Vitamin C, Vitamin D, Vitamin E, and Vitamin K. Vitamin C or ascorbate is a water-soluble vitamin found in citrus and other fruits, berries and vegetables. It is found as a form of ascorbic acid. It is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. Experts agree—astaxanthin is the antioxidant for endurance. Nutritionists and trainers share tips for maximizing results from this trending supplement. Maybe you don't have to pass up the treats aisle. Support your goals AND your sweet tooth. Why The Vitamin Shoppe ®? Vitamins are organic compounds that living organisms require in small amounts for the normal growth, metabolism, and health. Unlike carbohydrates, proteins, and fats, vitamins do not provide energy or serve as structural building blocks. Vitamins are organic molecules (or a set of closely related molecules called vitamers) that are essential to an organism in small quantities for proper metabolic function. These essential nutrients cannot be synthesized in the organism in sufficient quantities for survival, and therefore must be obtained through consumption. In this article, we will explore the 10 most important vitamins, their functions, their sources, and why they are so critical for survival. Along the way, we’ll uncover how these microscopic nutrients hold the key to vitality, longevity, and the prevention of disease. 1. Vitamin A – The Vision and Growth Vitamin.