Vitamins

• BiotinA B vitamin the body needs to metabolise fats, glucose and amino acids. Deficiency is rare, but high-dose supplements can make some laboratory tests give false results.
• FolateA B vitamin needed to make DNA and for cell division. Folate occurs naturally in food; folic acid is the form added to fortified foods and most supplements.
• NiacinA B vitamin, also called vitamin B3, that the body turns into NAD — a coenzyme more than 400 enzymes need. The body also makes some from tryptophan in protein.
• Pantothenic acidA B vitamin, also called vitamin B5, that the body uses to make coenzyme A, essential for building and breaking down fats. Almost every food contains some.
• RiboflavinA B vitamin, also called vitamin B2, that forms two coenzymes needed for energy production, growth and the metabolism of fats and drugs. Milk, eggs and meat are rich sources.
• ThiaminA B vitamin, also called vitamin B1, that is critical for turning food into energy. The body stores very little, so it needs a steady supply from food.
• Vitamin AA fat-soluble vitamin needed for vision, immune function, growth and reproduction. Animal foods provide it ready-made; plants provide carotenoids the body converts.
• Vitamin B12A vitamin found naturally only in animal foods, needed for nerves, red blood cells and DNA. Absorbing it depends on stomach acid and a protein the stomach makes.
• Vitamin B6A water-soluble B vitamin involved in more than 100 enzyme reactions, mostly in protein metabolism. Fish, organ meats, potatoes and fortified cereals are rich sources.
• Vitamin CA water-soluble vitamin the body cannot make, needed to build collagen and for immune function. It improves iron absorption from plants; too little causes scurvy.
• Vitamin DA fat-soluble vitamin that lets the gut absorb calcium. Very few foods contain it naturally, and the skin makes it — as vitamin D3 — from sunlight.
• Vitamin EA group of fat-soluble antioxidants. Only one form, alpha-tocopherol, meets the body's needs; nuts, seeds and vegetable oils are among the best sources.
• Vitamin KA fat-soluble vitamin the body needs to make proteins for blood clotting and bone. It comes mainly from green leafy vegetables, and gut bacteria make some too.