Vitamin B12 (Cobalamin)

Vitamin B12 is a water-soluble nutrient. Water-soluble nutrients dissolve in water. After the body uses these nutrients, leftover amounts leave the body through the urine.

Typically, water-soluble nutrients can not be stored by the body. This vitamin is special, because the body can store it for years in the liver. Because of this, a vitamin B12 deficiency is very rare.

Function

This nutrient is important for metabolism. Metabolism within the body includes the processes of energy generation and use; including nutrition, digestion, absorption, elimination, respiration, circulation, and temperature regulation.

This vitamin, like the other B vitamins, is important for metabolism. It helps in the formation of red blood cells and in the maintenance of the central nervous system.

Elderly are the most at risk. However, deficiency can result from being unable to use this vitamin. Inability to absorb vitamin B12 from the intestinal tract can be caused by a disease known as pernicious anemia. Additionally, strict vegetarians or vegans who are not taking in proper amounts of B12 are also prone to a deficiency state.

Food Sources

Vitamin B12 is found in eggs, meat, poultry, shellfish, milk, and milk products.

The human body stores several years´ worth of this nutrient, so nutritional deficiency of this nutrient is extremely rare. Although, people who follow a strict vegetarian diet and do not consume eggs or dairy products may require supplements of this vitamin.

Deficiency Side Effects

Vitamin B12 deficiencies occur when the body is unable to properly use the vitamin. Pernicious anemia can make the body unable to absorb this nutrient from the intestinal tract.

Because this nutrient comes primarily from animal products, people who follow a strict vegetarian or vegan diet and do not consume eggs or dairy products may require vitamin B12 supplements. (Non-animal sources of this nutrient exist but are highly variable in their B12 content. They are considered unreliable sources of this nutrient).

Those who had surgery on specific parts of the small intestine or stomach are also prone to a deficiency if they do not take B12 supplements.

Low levels of B12 can cause anemia, numbness or tingling in the arms and legs, weakness, and loss of balance.

Recommended dietary allowances (RDAs) are defined as the levels of intake of essential nutrients that, on the basis of scientific knowledge, the Food and Nutrition Board believes meets the known nutrient needs of practically all healthy persons.

The best way to get the daily requirement of essential vitamins is to eat a balanced diet that contains a variety of foods from the food guide pyramid.

Specific recommendations for each nutrient depends on age, gender, and other factors (such as pregnancy).