Vitamin B12

Vitamin B₁₂ is one of the eight vitamins in the vitamin-B family that is readily available in fish, meat, liver, and dairy products. The other seven in that family are vitamins B1, B2, B3, B₅, B6, B₇, and B₉. Plant foods do not have vitamin B₁₂ unless they are strengthened with other nutrients.

Vitamin B₁₂ is also called cobalamin and B complex vitamin. It is a water-soluble vitamin, meaning that it dissolves easily in water. Once the body absorbs the vitamin, the leftover is passed out through urine. If necessary, the human body can store vitamin B₁₂ in the liver for several years. Like other members of the B family, vitamin B₁₂ is primarily important for metabolism in the body. Vitamin B₁₂ also assists in the maintenance of the central nervous system (CNS) and the production of red blood cells (RBC). It is possible to artificially produce vitamin B₁₂.

Brief History

It is said that the discovery of vitamin B12 was essentially an accident. Until the early 1920s, there was little cure for anemia, and a variation of anemia called pernicious anemia was typically considered fatal. George Hoyt Whipple was an American physician, educator, and administrator who wanted to find out if a certain kind of diet helped dogs recover from induced anemia. He would drain blood from dogs and would feed them different food to test their recovery. Whipple found that the dogs that were fed a high amount of raw liver would recover the fastest. So he hypothesized that ingesting liver would cure pernicious anemia. He published his findings in 1920.

George Richards Minot, an American medical researcher, and William Parry Murphy, an American physician wanted to find out exactly what substance in liver cured anemia in dogs. After a series of careful clinical research, Minot and Murphy isolated the substance as iron. During this research, they found another completely different substance in liver that cured pernicious anemia in humans. This substance however, had no impact on dogs. This specific finding from the liver juice was by pure coincidence. They published their findings in 1926. However, even after their publication, for several years, patients were made to eat large amounts of raw liver or drink large portions of liver juices.

For their combined work, Whipple, Minot, and Murphy received the Nobel Prize in Physiology or Medicine in 1934. In 1928, American protein scientist Edwin Joseph Cohn prepared a liver extract that was 50–100 times more potent than the natural liver products. This finding in essence addressed the anemia problem significantly, and also led to the discovery of soluble vitamin B₁₂ from bacterial broths. In 1948 pure vitamin B₁₂ was extracted by researchers Mary Shaw Shorb and Karl August Folkers. Finally, in 1956, Dorothy Crowfoot Hodgkin, a British biochemist, and her team determined the chemical structure of vitamin B₁₂ based on crystallographic data. Hodgkin won the Nobel Prize in Chemistry for developing protein crystallography. In the 1950s, new processes were invented to mass-produce B₁₂ from bacterial culture, which led to the modern treatment for anemia.

Overview

Because of its importance in the development and proper functioning of the blood cells, brain, central nervous system (CNS), nerves, and other body parts, vitamin B₁₂ is of great importance in medical science. It is used for the treatment of vitamin B₁₂ deficiency and pernicious anemia, and research has been conducted into its effect on other conditions. While it was believed that vitamin B₁₂ might prove useful in preventing heart disease due to its ability to reduce levels in homocysteine in the blood, it has not conclusively been shown to effectively reduce the risk of heart disease. Similarly, the vitamin's effect on homocysteine levels has been investigated as it relates to dementia and Alzheimer's disease, but there is not yet conclusive evidence that it works as a preventative or treatment.

Vitamin B₁₂ has also been the subject of research in the treatment of many other conditions, with little conclusive evidence. These include ALS (Lou Gehrig’s disease), diabetes, multiple sclerosis, age-related macular degeneration (AMD), liver and kidney disease, osteoporosis, Lyme disease, AIDS, inflammatory bowel disease, asthma, gum disease, allergies, vitiligo (skin disease), and some cancers. Some supplements have marketed B vitamins as helpful in treating mood, concentration, energy, and immune system problems, and as a way to help slow aging, but there is little or no evidence supporting such claims. Likewise, further research is needed before any effect of vitamin B₁₂ on conditions such as swollen tendons, male infertility, various sleep disorders and depression, ringing in the ears, skin infections, and bleeding can be established.

It is common and likely safe to take vitamin B₁₂ as oral dietary supplements or as a gel for application inside the nose. For skin ailments, it is common to apply vitamin B12 on the skin as a gel/cream and sometimes simultaneously with avocado oil. It can be taken as an injection as well. In general, vitamin B12 is often used in combination with other B vitamins. Natural sources of vitamin B₁₂ include beef liver, meat, shellfish, eggs, milk, poultry, some fortified breakfast cereals, and some fortified nutritional yeasts. Food labels provide information about the presence of B₁₂ in the item.

The absence of sufficient amounts of vitamin B₁₂ in the body is called vitamin B₁₂ deficiency. Red blood cells (RBC) in the body play a key role in carrying oxygen around the body; a deficiency of B₁₂ leads to the body producing a higher number of RBC to compensate. This situation is called megaloblastic anemia. Vitamin B₁₂ deficiency is more common in elderly people, with approximately 10 percent of the people over the age of 75 affected. A person need not have anemia to show signs of neurological symptoms of B₁₂ deficiency. In such cases, the sooner it is addressed, the better the chances of avoiding irreversible damage to the body. Some of the other symptoms of B₁₂ deficiency are being out of breath, loss of appetite and weight loss, headache, lethargy, vision problems, ringing in the ears, feeling faint, yellowing of the skin, tingling in the hand/feet, mouth ulcers, mood changes, irritability, depression, dementia, and confusion. Many of these symptoms are general to a wide variety of disorders, however, and do not necessarily point to vitamin B₁₂ deficiency.

Known causes of vitamin B₁₂ deficiency are pernicious anemia, unfortified vegan diets, stomach ulcers, and some digestive conditions such as Crohn’s disease. Some medications taken for indigestion can also result in vitamin B₁₂ deficiency. A simple blood test is sufficient to diagnose B₁₂ deficiency; further tests can pinpoint the cause. Remedies generally include vitamin B₁₂ supplements, injections, and vitamin B₁₂ rich food.

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