Vitamin B12, the most complex of all the vitamins, plays a vital role in the production of new blood cells and in nervous system health. A dietary deficiency in vitamin B12 may lead to a condition known as anemia that is characterized by lethargy, loss of breath and difficulty resisting infection. By adding foods rich in vitamin B12 to your diet, you'll promote the health of your circulatory, nervous and immune systems.
Beef
About 80 percent of vitamin B12 is stored in the liver, and the best dietary source of the vitamin is beef liver. A single slice of braised beef liver contains 48 micrograms, or mcg, or 800 percent of the U.S. Food and Drug Administration's recommended daily value. A 3 oz. sirloin steak offers up 40 percent of the recommended daily value, whereas a double patty burger serves up 30 percent.
Seafood
Shellfish are second only to beef liver as a source of vitamin B12. Three ounces of clams gives your body over 34 mcg, or 570 percent of the recommended daily value, of the vitamin. Although not as vitamin-rich as shellfish, wild trout, salmon, haddock and tuna provide 90, 80, 20 and 15 percent of the recommended daily value, respectively.
Milk and Dairy Products
Diary products offer a vegetarian-friendly option for vitamin B12 in the diet. One cup of whole milk or one ounce of cheese contains 15 percent of the recommended daily value; a cup of yogurt contains 25 percent.
Poultry and Eggs
Although the concentrations of vitamin B12 are comparatively low, poultry and eggs are still an adequate source. A roasted chicken breast provides your body with about 12 percent of the amount of this vitamin that it needs per day, and an egg gives you 10 percent.
Other Sources
Fermented soy beans, algae and seaweed may all contain vitamin B12, but it is unclear whether the body is able to absorb the vitamin from these sources. Vegetarians and vegans at risk of developing a deficiency should look for textured soy protein, margarine, breakfast cereals, soy milk, nutritional yeast and vegetable stock fortified with vitamin B12.
