Vitamin B12 is naturally found in animal products including fish, meat, poultry, eggs, milk, and milk products. Vitamin B12 is generally not present in plant foods, but fortified breakfast cereals are a readily available, non-animal source of vitamin B12 with high bioavailability. Some nutritional yeast products also contain vitamin B12. Fortified foods vary in formulation, so it is important to read product labels to determine which added nutrients they contain.
In dietary supplements, vitamin B12 is usually present as cyanocobalamin, a form that the body readily converts to the active forms methylcobalamin and 5-deoxyadenosylcobalamin. Dietary supplements can also contain methylcobalamin and other forms of vitamin B12.
|Food||Micrograms (mcg) per serving|
|Liver, beef, braised, 1 slice||48.0|
|Clams, cooked, breaded and fried, 3 ounces||34.2|
|Breakfast cereals, fortified with 100% of the DV for vitamin B12, 1 serving||6.0|
|Trout, rainbow, wild, cooked, 3 ounces||5.4|
|Salmon, sockeye, cooked, 3 ounces||4.8|
|Trout, rainbow, farmed, cooked, 3 ounces||3.5|
|Cheeseburger, double patty and bun, 1 sandwich||2.1|
|Haddock, cooked, 3 ounces||1.8|
|Breakfast cereals, fortified with 25% of the DV for vitamin B12, 1 serving||1.5|
|Yogurt, plain, 1 cup||1.4|
|Beef, top sirloin, broiled, 3 ounces||1.4|
|Tuna, white, 3 ounces||1.0|
|Milk, 1 cup||0.9|
|Cheese, Swiss, 1 ounce||0.9|
|Beef taco, 1 taco||0.8|
|Ham, cured, roasted, 3 ounces||0.6|
|Egg, large, 1 whole||0.6|
|Chicken, roasted, ½ breast||0.3|
Source: Office of Dietary Supplements, available at http://ods.od.nih.gov/factsheets/vitaminb12#h3
The U.S. Department of Agriculture’s Nutrient Database Web site lists the nutrient content of many foods and provides a comprehensive list of foods containing vitamin B12.