Vitamin B-12, also known as cobalamin, is a water-soluble vitamin found naturally in meat, poultry, fish, dairy products and eggs. It can also be taken as a supplement. Symptoms of vitamin B-12 deficiency include anemia, fatigue, and loss of appetite; weigh loss and tingling on fingers and toes.
Vitamin B-12 is used to treat megoblastic anemia — a type of anemia characterized by abnormally large red blood cells — which can be caused by vitamin B-12 deficiency. Vitamin B-12 supplements also treat pernicious anemia, caused by an absence of intrinsic factor in the stomach. Intrinsic factor is necessary for the absorption of vitamin B-12; if intrinsic factor is missing, lifelong vitamin B-12 supplementation may be necessary.
Vitamin B-12 works alongside vitamins B-6 and B-9 to regulate blood levels of homocysteine, an amino acid found in the blood. People with high levels of homocysteine are approximately 2.5 times more likely to have a stroke and 1.7 times more likely to suffer from coronary artery disease than people with normal homocysteine levels, according to the University Of Maryland Medical Center. However, it is unclear if a raised homocysteine level causes heart disease or is simply an indicator that someone has it. While it is better for adequate amounts of vitamin B-12 to be obtained from the diet, people with raised levels of homocysteine who have a history of heart disease may benefit from vitamin B-12 supplements.
Women with higher amounts of folate in their diets have a lower incidence of breast cancer, reports the University of Maryland Medical Center. As vitamin B-12 works alongside folate in the body, it is possible vitamin B-12 may contribute to a decreased risk of breast cancer. Women with breast cancer have been shown to have lower blood levels of vitamin B-12 than women who do not have breast cancer, says the Mayo Clinic. It is unclear if vitamin B-12 on its own can reduce the risk of breast cancer.
A vitamin B-12 deficiency causes homocysteine to accumulate in the blood, which may interfere with the metabolism of neurotransmitters. Elevated levels of homocysteine are associated with Alzheimer’s disease and dementia. Low vitamin B-12 intake is also related to a decline in cognitive function. Vitamin B-12 supplementation may help slow the rate of cognitive decline, but scientific evidence for this use is unclear.
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Vitamin B-12, or Cobalamin, is the largest and most complex vitamin currently known to man. A slight deficiency of vitamin B-12 can lead to anemia, fatigue, mania, and depression, while a long term deficiency can potentially cause permanent damage to the brain and central nervous system. Vitamin B-12 can only be manufactured by bacteria and can only be found naturally in animal products. Vitamin B-12 can be consumed in large doses because excess is excreted by the body or stored in the liver for use when supplies are scarce. Stores of B-12 can last for up to a year.
Top 10 Foods Highest in Vitamin B12 (Cobalamin)
#1: Clams, Oysters, and Mussels
Shellfish are a great source of vitamin B12 and can be eaten raw, baked, steamed, fried, or made into chowder. In addition to vitamin B12 shellfish are a good source of zinc, copper, and iron. Clams provide the most vitamin B-12 with 98.9μg per 100g serving, accounting for 1648% of the RDA. That is 84μg (1401% RDA) per 3 ounce serving, and 187.9μg (3132% RDA) in 20 small clams, or 9.4μg (156.6 %RDA) in one small clam. Mussels and oysters are also good sources of B12 providing 600% RDA and 400% RDA per 100 gram serving.
Often appearing on the culinary scene as pâté, liver can also be prepared steamed or fried with onions and herbs. The liver of most any animal is packed with vitamin B-12, the highest on the list are: Lamb, beef, veal, moose, turkey, duck, and goose respectively. Lamb liver provides 85.7μg (1428% RDA) of vitamin B12 per 100g serving, or 72.85μg (230% RDA) in a 3 ounce serving.
#3: Caviar (Fish Eggs)
Caviar and fish eggs are most often eaten as a garnish or spread. The eggs of whitefish contain the most vitamin B-12 with 56.4μg (940% RDA) per 100g serving. Caviar contains a third of that with 20μg (333% RDA) of vitamin B12 per 100g serving, 5.6μg (93% RDA) per ounce, and 3.2μg (53% RDA) per tablespoon. Chicken eggs, by comparison, only offer 1.29μg (22% RDA) of vitamin B-12 per 100g serving, or 0.65μg (11% RDA) per egg.
Popular in Mediterranean, Japanese, and Hawaiian cuisine, octopus is a vitamin B-12 rich food. Cooked octopus provides 36μg of vitamin B-12 per 100 gram serving accounting for 600% of the RDA. That is 30.6μg (510% RDA) per 3 ounce serving, or 10.2μg (170% RDA) per ounce. Raw octopus provides about half as much vitamin b12 with 20μg (333% RDA) per 100 gram serving, 17μg (283% RDA) in a 3 ounce serving, and 5.67μg (94.33% RDA) per ounce.
Known for their omega 3 fats and for being a high protein food, fish are also a good source of vitamin B12. Mackerel provides the most vitamin B-12 with 19μg per 100g serving (317% RDA), followed by Herring (312% RDA), Salmon (302%), Tuna (181%), Cod (167%), Sardines (149%), Trout (130%), and Bluefish (104%).
#6: Crab and Lobster
Crab and lobster are most commonly served baked, steamed, or in bisque. A 100g serving of crab contains 11.5μg of vitamin B12 (192% of the RDA), that is 15.4μg (257%RDA) per leg (134g). Lobster will provide 4.04μg (67% RDA) per 100g serving, or 6.59μg (110% RDA) in an average whole lobster (163g).
In addition to being a vitamin B12 rich food, beef is also a good source of protein, zinc, and heme-iron. The amount of vitamin B-12 in beef depends on the cut, lean fat-trimmed chuck contains the most vitamin B12 with 6.18μg (103% RDA) per 100g serving, 11.49μg (103% RDA) in a chuck steak, and 5.25μg (88% RDA) in a 3 ounce serving. Chuck is followed by sirloin (62% RDA), rib-eye (60% RDA), and ribs (58% RDA).
#8: Lamb (Mutton)
Lamb is a common meat in the Middle East, Mediterranean, East Asia, Australia, New Zealand, and most of Europe. Lamb is a high cholesterol food so be sure to look for lean cuts which are higher in B12 anyway. Lamb also provides high amounts of protein, and zinc. The shoulder is the cut of lamb with the most vitamin B-12 providing 3.71μg (62% RDA) per 100g serving, 5.82μg (97% RDA) per pound, and 3.15μg (53% RDA) in a 3 ounce serving. The shoulder is followed by the foreshank and leg which provides 53% of the RDA per 100g serving, and lamb chops which provide 51% of the RDA for vitamin B12 per 100 gram serving.
Despite being a high cholesterol food, cheese is a good source of calcium, protein, and riboflavin (Vitamin B2). The amount of vitamin B12 in cheese depends on type and variety, Swiss cheese provides the most with 3.34μg (56% RDA) per 100g serving, followed by Gjetost (40% RDA), Mozzarella (39% RDA), Parmesan (38% RDA), Tilsit (35% RDA), and Feta (28% RDA).
When it comes to chicken eggs the raw yellow has most of the vitamin B-12 with 1.95μg per 100g serving (33%), however, this equates to 0.33μg per yolk or just 6% of the RDA. The eggs of other animals are higher with a goose egg providing 7.34μg (122% RDA) of vitamin B-12 per 100g serving, and a duck egg providing 3.78μg (63% RDA).
To your health,
The staff at Advance Health and Wellness Solutions, Inc
- Mayo Clinic
- Office of Diatary Supplements: Vitamin B12
- University of Maryland Medical Center: Vitamin B12