High doses of certain vitamins can be dangerous, even fatal. Add to that the complication that the body can only store some vitamins for only relatively short periods. The fat-soluble vitamins A, D, E, and K are absorbed along with fat from various foods and are stored in the body. The water-soluble vitamins, the B's and C, generally are not stored. These are the amounts of vitamins, minerals, and proteins believed to be needed by most people each day, to remain healthy, according to the U.S. government.
Government policy recommends the values needed by the general population.
Extremely sensitive methods of measuring the potency or quantity of vitamins have been developed because they are present in foods in very small amounts. Other vitamins are expressed by weight in micrograms or milligrams. To illustrate the small amounts needed by the human body, let's start with an ounce, which is 28.4 grams. Then, just one ounce of this vitamin could supply the daily needs of 4,724,921 people. The table below describes the U.S. Recommended Daily Allowance of each vitamin, what it does, and the food sources.