The vitamin B6 content of foods is expressed in milligrams. It's important to note, however, that the bioavailability of pyridoxine may differ in different foods. "Bioavailability" refers to the amount of the vitamin that is delivered to its site of action in the body.
The recommended daily allowance (RDA) for adults is in the range of 1.3mg to 1.5mg. A meal such as a piece of salmon and a baked potato would contain this amount of vitamin B6. For optimal health, 25-50mg a day is recommended, and taking up to 100mg per day is considered safe.
Women trying to reduce premenstrual symptoms can take elevated levels of pyridoxine with relative safety (see "How much vitamin B6 is too much?").
It's interesting to note that the body's need for vitamin B6 increases as protein consumption increases.
Click here to view a complete list of RDA values for this vitamin.