Vitamins are essential for your body to function and fight off disease. Your body cannot produce vitamins itself, so you must get them through food you eat or through supplements. Vitamins are used in many different ways inside your body. Good nutrition promotes health, while nutritional deficiencies can lead to many chronic diseases. For the human body to complete vital daily tasks, it must be given a wide and complex variety of key vitamins and minerals. They strengthen immune function and convert food into energy. They detoxify chemicals and medications, and manufacture neurotransmitters, hormones and other key signaling molecules in the body. They also maintain tissue repair and cell regeneration. Optimal Health Plus, NutriPlus, and Revital b12 contain Methyl B Vitamins that have many important functions such as proper energy metabolism, immune and nerve cell function.