Where Does Vitamin B12 Come From?

Many types of fish contain vitamin B-12.
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Vitamin B-12 fills many jobs, from putting pep in your step to supporting your active lifestyle by making sure you have healthy red blood cells. If you eat a variety of fish, meat and dairy products, chances are you have plenty of vitamin B-12 in your system. But if your diet tends to be mostly vegetables and beans, you may need to consult with your doctor about taking a supplement.


    Vitamin B-12 activates different processes that ensure your optimal health by producing energy and red blood cells and keeping nerves working properly. It also helps synthesize the amino acid methionine, and it makes s-adenosylmethionine, or SAMe. SAMe is essential for producing DNA, proteins and neurotransmitters, but as a supplement it’s used to treat osteoarthritis and relieve depression. Vitamin B-12 also removes the amino acid homocysteine from the bloodstream. That may protect your heart because high levels of homocysteine are associated with an increased risk of cardiovascular disease. Women need to include 2.4 micrograms of vitamin B-12 in their daily diet.

Best Sources

    Vitamin B-12 only comes from animal products, where it’s synthesized by bacteria. Most people get plenty in their diet, but if you follow a vegan diet you’ll need to ask your doctor about taking a supplement. The absolute top source of vitamin B-12 is beef liver. You’ll get 70.66 micrograms from a 3-ounce serving of pan-fried beef liver. That’s equal to almost an entire month of your recommended daily intake. Some of it may be excreted from your system, but the liver stores vitamin B-12, so eating such a large amount at one time won’t go entirely to waste.

Fish, Meat and Poultry

    Many types of fish are better sources of vitamin B-12 than meats and poultry. Canned clams are at the top of the list with 16 micrograms in a 3-ounce serving. They’re followed by oysters and crab, which contain 10 to 13 micrograms. Canned tuna, pollock and salmon have 3 to 5 micrograms, but that still gives you more than your recommended daily intake in one serving. Ground beef and chuck roast have 100 percent of your daily value, and ham has about half. Turkey and chicken have 0.3 to 1.2 micrograms per serving.

Dairy Products and Eggs

    One hard-boiled egg, 1 cup of milk and a 1-ounce serving of Swiss cheese all supply 1 microgram, or 42 percent of your daily value of vitamin B-12. The same serving of other popular cheeses -- mozzarella, muenster, provolone, American and cheddar -- supplies 10 to 27 percent of your daily intake. If you had a breakfast made from one hard-boiled egg, a slice of cheddar cheese and a cup of milk, you would get 75 percent of your daily value.

Fortified Cereals

    An exception to animal-based food sources comes from ready-to-eat cereals that are fortified with vitamin B-12. Some types of cereals made from a variety of different grains, such as wheat, corn and rice, have as much as 6 micrograms of vitamin B-12 in a serving. Some have 1 to 2 micrograms, but be sure to read the nutrition facts label because many cereals don’t have any vitamin B-12.

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