Vitamin B12 deficiency can have many effects, including a lack of energy. Balancing the effects of vitamin B12 starts with the diet. Vitamin B12 is readily available in many common foods that you probably eat every day. However, if you are vegetarian or vegan, or if you have difficulty absorbing vitamin B12, you might need to take special care to get more of it into your diet.
Clams and mollusks have the highest concentration of natural, bioavailable B12, at 14 times the minimum dietary supplement per serving, according to the National Institute of Health's B12 Dietary Supplement Fact Sheet. The next best source is beef liver, followed by trout, salmon and top sirloin beef. Pork and chicken provide small amounts of B12, but have less than one-eighth as much as steak.
Cereals and Breads
Many breads and cereals contain fortified bioavailable vitamin B12. Often, yeast used to make bread is fortified with vitamin B12. The B12 content of breads and cereals is listed in their Nutritional Information, so you can tell if a bread or cereal has been fortified with B12 by checking the package information. Fortified breads and cereals are a good source of vitamin B12, and have more than chicken or pork.
Milk and Eggs
Yoghurt is the best option to get your vitamin B12 through dairy products. Yoghurt has one-quarter of the recommended daily allowance of vitamin B12. Milk, eggs and cheese are a decent source of vitamin B12. Milk and eggs offer a better dose of B12 than both pork and chicken, but you would still have to eat 10 eggs per day to get your minimum vitamin B12 amount.
Vegan Sources of B12
You can meet your B12 needs by eating organic fresh fruits and vegetables. Mushrooms and root vegetables that have not been commercially washed contain vitamin B12.
It is a common misconception that plants such as soy, spirulina and seaweed can supply the body with adequate B12. The reality is that no plant is a good source of vitamin B12.