What Foods Contain Large Amounts of Vitamin B12?
Few foods contain large amounts of vitamin B12, but most nonplant protein sources, like meat and dairy products, contain enough B12 that most people meet their intake requirements. Vitamin B12 has long been the bane of vegan diets since there are no significant vegan sources of the nutrient, and deficiency can result in serious and permanent impairments. Fortunately, many foods are fortified with considerable amounts of B12.
Identification
Vitamin B12 is an essential, water soluble vitamin. It's also known as cobalamin because it contains the element cobalt. Vitamin B12 is important for cellular metabolism, DNA and fatty acid synthesis, and energy production. It is crucial to the health of neurons and red blood cells. B12 deficiency can cause irreparable harm to the brain and spinal cord, anemia, and dementia.
Shellfish
The best source of vitamin B12 by far is mollusks, clams and a few other species of shellfish. A cooked 3-oz. serving contains roughly 84 μg, or about 1,400 percent of the 6 μg recommended daily intake. Breaded and fried clams contain significantly less B12, with about 1.1 μg per 3/4-cup serving. A single medium sized oyster contains about 2.75 μg, almost half the recommended daily intake.
Liver
The second richest source of vitamin B12 is liver, especially beef liver. Though cows are herbivorous, they obtain B12 from bacterial fermentation that occurs inside their digestive tract. A diet of beef liver was prescribed for pernicious anemia, and proved to be the cure that wiped it from the list of deadly diseases in the 1930s.
Fish
Several species of fish are relatively high in vitamin B12 content. Wild rainbow trout tops the list with about a full day's worth of B12 in a single 3-oz. serving. Farmed trout has somewhat less vitamin B12 content. Also rich in B12 is salmon, with about 80 percent of the daily recommended intake per 3-oz. serving. Haddock and tuna contain considerably less B12, but remain significant food sources.
Vegan Sources
Vitamin B12 is simply not present in higher order plants. It is produced primarily by bacteria and fungi. Vegans have traditionally claimed that various seaweed, grains, roots and mushrooms contain B12, but none of these sources has been found to contain nutritionally available forms of the vitamin. Thus, the only reliable sources of B12 in a vegan diet is in fortified foods such as cereals, certain breads, milk substitutes, and soy-based meat analogues. A single serving of an enriched cereal, for example, contains 100 percent of the recommended daily intake.
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