Vitamin B12

From WikiMD's Food, Medicine & Wellness Encyclopedia

Vitamin B12 is a vitamin that is essential to the production of DNA (the genetic material in cells) and [[red blood cells and in the functioning of the nervous system.

Cobalamin skeletal
Vitamin B12 capsule
Vitamin B12

Vitamin B12, also known as cobalamin, is a water-soluble vitamin essential for a variety of bodily functions, including the production of red blood cells, the maintenance of nervous system health, and the synthesis of DNA. It is an essential nutrient, which means that the human body cannot produce it and must obtain it through diet or supplements. This article discusses vitamin B12, including its functions, sources, deficiency, and toxicity.

Roles of Vitamin B12[edit | edit source]

Vitamin B12 serves multiple essential functions in the body, including:

  • Formation of oxygen-carrying red blood cells: Vitamin B12 is required for the production of red blood cells, which circulate oxygen throughout the body.
  • B12 is necessary for the synthesis of DNA, the genetic material of all cells.
  • Vitamin B12 promotes the maintenance of the myelin sheath, a protective coating that surrounds nerve fibers and ensures the proper transmission of nerve signals, for the sake of nervous system health.
  • B12 facilitates the conversion of homocysteine to methionine, thereby decreasing homocysteine levels in the blood. Homocysteine levels are related to an increased risk of cardiovascular disease.

Sources of Vitamin B12 in the Diet[edit | edit source]

Vitamin B12 is predominantly found in foods derived from animals, such as:

  • Beef, liver, chicken, and pork are types of meat.
  • Salmon, tuna, and sardines are fish.
  • Clams, oysters, and mussels are shellfish.
  • Milk, cheese, and yogurt are examples of dairy items.
  • Eggs
  • Some fortified foods, including breakfast cereals, plant-based milk substitutes, and nutritional yeast, may contain added vitamin B12.

Since plant-based foods are typically deficient in vitamin B12, vegans and vegetarians may require fortified foods or supplements to meet their daily needs.

Vitamin B12 Deficiency[edit | edit source]

Deficiency in vitamin B12 can result from insufficient dietary intake, malabsorption, or specific medical conditions. The following are symptoms of vitamin B12 deficiency:

  • Weakness and weariness
  • Pale skin
  • Anemia
  • Constipation or loose stools
  • loss of hunger
  • Tingling or numbness in the hands and feet
  • Problems with balance and coordination
  • Memory loss, confusion, or dementia

Elderly individuals, those with gastrointestinal disorders, those who have undergone gastrointestinal surgery, and vegans and vegetarians are at increased risk for vitamin B12 deficiency. Vitamin B12 deficiency is typically treated with oral or injectable supplements of the vitamin.

B12 Vitamin Toxicity[edit | edit source]

Due to its water-solubility and the body's capacity to excrete excess amounts through urine, vitamin B12 has an extremely low toxicity potential. No upper intake level has been established for vitamin B12, and there are no known adverse effects associated with consuming large amounts of vitamin B12 through food or supplements. Before taking high-dose supplements, however, it is always advised to consult a medical professional.

Detailed article on vitamin B12[edit | edit source]

Vitamin B12 Resources
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Contributors: Prab R. Tumpati, MD