The vegan diet -- rich in fruits, vegetables, whole grains, and legumes -- provides an abundance of vitamins and minerals to meet one’s nutritional needs. However, there is one vitamin, called vitamin B12, which does present a genuine nutritional issue, although one that is easily solved. When vitamin B12, which is produced by bacteria and other one-celled organisms in the small intestines of animals, is made by humans, it is not well absorbed and retained. Found mainly in animal products, small amounts may be found in plant products due to bacterial contamination. However these plant and fermented foods, such as spirulina, sea vegetables, tempeh, and miso, do not provide an active and reliable source, so vitamin B12 must be obtained elsewhere in the diet.
For individuals following a diet free of all animal products, vitamin B12 needs can easily be met by consuming a variety of vegan foods. Fortified breakfast cereals, fortified soymilk, and fortified meat analogues contain a reliable source of the vitamin. Nutritional yeast, such as Red Star Vegetarian Support Formula, is also a reliable source. Be sure to check the Nutrition Facts Label or the ingredient list to ensure you are receiving the active form of vitamin B12, called cobalamin or cyanocobalamin. Most common multivitamins, from Flintstones to One-A-Day to Stress Tabs, also contain B12. Regular intake of vitamin B12 is important to meet one’s nutritional needs. The recommended dietary allowance in adults is 2.4 micrograms per day, with increased requirements for women who are pregnant or breastfeeding. Ensuring that vitamin B12 needs are met as one ages becomes even more critical as deficiencies are common among the elderly.
If you are unable to meet the recommended daily allowance through diet alone, taking a B12 supplement is advisable.