The best-known foods with vitamin B12 are liver, caviar, and oysters. However, these food sources are not ideal B12 foods for vegans and are not recommended for those with cholesterol or heart issues. Thankfully, there is no need to take B12 every day since the livers of healthy individuals contain enough reserves for at least five years.
Chemical composition: cyanocobalamin and other similar substances.
Vitamin B12 sources: The only living things capable of synthesizing this vitamin are bacteria and other microorganisms such as yeasts. The bacteria usually found in the mouth or the intestine also produce vitamin B12, although it is not assured that the body can assimilate it.
- Higher animals (fish, mammals) do not produce this vitamin, but they store it in their tissues, particularly in the liver. Milk and eggs also contain vitamin B12, as do meat and fish.
- Plants and higher algae do not produce or store vitamin B12. However, they may provide it in small amounts through contamination by certain bacteria that produce vitamin B12, as is the case with certain seaweed; and by containing yeasts that produce B12. This is the case with certain fermented products such as beer (with or without alcohol), tempeh (fermented soybean), and even bread (in tiny amounts).
- Unicellular or blue-green algae such as spirulina, which produce significant amounts.
Vitamin B12 function: Cell division, the formation of red blood cells, and myelin (a substance that protects the nerve fibers).
Vitamin B12 Deficiency Symptoms
A lack of vitamin B12 results in anemia in which the red blood cells are more extensive than usual. About 90 percent of macrocytic anemias in temperate climates are due to B12 or folic acid deficiencies. The production of red blood cells depends on these vitamins. Vitamin B12 is also essential for the maintenance of the brain and especially the spinal cord.
Microorganisms in the soil, gut, and mouth produce vitamin B12. The amount the body needs partially correlates with the protein intake. Thus, the higher the intake of protein, the more B12 will be required. Complete vegetarians and vegans face a higher risk for this deficiency, but they have the same risk for pernicious anemia.
Vitamin B12 is absorbed from foods containing it and from amounts produced in the mouth and intestines. It is stored in the liver. If the stored B12 is depleted, a deficiency may occur. A protein produced in the stomach wall, called the “intrinsic factor,” greatly aids the vitamin’s absorption. This factor combines with B12 and acts as a transfer agent, guiding the vitamin across the gut lining into the blood.
Pernicious anemia is the result of a lack of intrinsic factor, not just from a lack of the vitamin entering the intestine. Lack of intrinsic factor may arise from atrophy of the cells producing it or from extensive surgery in which large portions of the stomach wall or intestine have been removed. In some regions of the world, a tapeworm may deprive the person of B12.
Deficiency risk: In theory, it could be said that strict vegetarians and vegans are at risk. However, in reality, there are very few cases. An ovolactovegetarian diet generally supplies sufficient vitamin B12.
The possibility exists that the body does not assimilate the vitamin B12 found in spirulina and plant-based foods such as tempeh. Due to this, it is suggested that strict vegetarians take B12 supplements.
Loss during the processing of foods: cooking destroys 30% of vitamin B12; the pasteurization of milk, about 10%.
Vitamin B12 Supplements
Top Foods With Vitamin B12
|Food (per each 100 g of raw edible portion)||Quantity|
|Malt beverage||0.020 µg|
|White bread||0.020 µg|
|Salted butter||0.125 µg|
|Baked chicken||0.300 µg|
|Whole cow’s milk||0.357 µg|
|Nonfat milk||0.378 µg|
|Natural yogurt||0.562 µg|
|Cottage cheese, 1% fat||0.633 µg|
|Fresh egg||1.00 µg|
|Camembert cheese||1.30 µg|
|Lean beef||1.40 µg|
|Tuna, canned in oil||2.20 µg|
|Fresh egg yolk||3.11 µg|
|Beef liver||46.8 µg|
|% Daily Value (based on a 2000 calorie diet)||provided by 100 g of this food|
George D. Pamplona-Roger, M.D. “Encyclopedia of Foods and Their Healing Power.” George D. Pamplona-Roger, M.D. Encyclopedia of Foods and Their Healing Power. Trans. Annette Melgosa. Vol. 1. Chai Wan: Editorial Safeliz, 2005. 395. Print.
Hardinge, Mervyn G and Harold Shryock. “Family Medical Guide.” Hardinge, Mervyn G and Harold Shryock. Family Medical Guide. Ed. Marvin Moore and Bonnie Tyson-Flynn. Vol. three. Oshawa; Washington, D.C.; Hagerstown: Pacific Press Publishing Association; Review and Herald Publishing Association, 1999. Three vols. 61. Print. [foods with vitamin B12]