Vitamin B12 Complex: What it Is and Why You Need It

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Introduction to Vitamin B12 Complex

Vitamin B12, also known as “B12 complex”, keeps your brain humming and your blood flowing. Without vitamin B12, your body can’t maintain your nervous system or create new blood cells, according to the Office of Dietary Supplements, a service of the National Institute of Health. It pays to know a little about this vitamin. However, if you have reason to believe you or someone you love may suffer from vitamin B12 deficiency, consult a physician. The information provided in this article is not intended to replace the advice of a trained medical professional.


Vitamin B12 is a water soluble vitamin with a complex crystal structure (See Reference 2). According to Medical Discoveries A-Z, its existence was first suspected in the early 1930s when scientists George Whipple, George Richards Minot, and William Perry Murphy discovered that beef liver could control pernicious anemia. This kicked off research into the “liver factor,” or curative property present in liver, which turned out to be vitamin B12. Dorothy Hodgkin received the 1964 Nobel Prize for mapping the structure of the vitamin, and Robert Burns Woodward succeeded in synthesizing it in 1971.


Vitamin B12 plays a vital role in the body. It maintains proper nervous system function, allows the body to make more red blood cells, and is vital in the formation of new DNA, according to MedLine Plus Medical Encyclopedia, a service of the National Institute of Health. Research is being conducted into whether vitamin B12 may help lower the risk of heart attack and dementia, but as yet, no strong link between adequate intake of vitamin B12 and reduced risk of either condition has been proven, according to the National Institute of Health’s Office of Dietary Supplements.

For those aged 14 years and older, the recommended daily allowance of vitamin B12 is 2.4 mg per day, with pregnant and nursing women requiring 2.6 and 2.8 mg, respectively, according to the Mayo Clinic. The clinic also recommends that older adults, who often have difficulty absorbing vitamin B12, eat foods fortified with the vitamin.

Food Sources

Vitamin B12 is naturally present in animal-based foods such as liver, clams, trout, salmon, milk, cheese, and eggs and beef, reports the Office of Dietary Supplements. Other good sources, according to the office, are fortified cereals, some of which have the 100 percent of the RDA, and some of which have 25 percent per serving.


Vitamin B12 deficiency is rare, since the body can store vitamin B12 for several years, according to the Office of Dietary Supplements. Those most at risk for deficiency, according to the office, are the elderly, those with digestive conditions such as celiac disease, and vegetarians who do not consume any animal-based foods. Symptoms of deficiency include difficulty maintaining balance, confusion, poor memory, and tremors. See your doctor if you experience any of these, as they can also be caused by other serious conditions.


Medical Discoveries A-Z: Vitamin B12

MedLine Plus Medical Encyclopedia: Vitamin B12

Office of Dietary Supplements: Vitamin B12

Mayo Clinic: Vitamin B12: Dosing.