Vitamin B12 Help

Vitamin B12 belongs to the class of vitamins referred to as water-soluble vitamins. Water-soluble vitamins dissolve in water when they enter the body and travel directly into the bloodstream. Excess amounts of water-soluble vitamins are usually excreted in the urine. Vitamin B12 is the only water-soluble vitamin that can be stored by the body.

Functions

Vitamin B12 is essential for maintaining the health of your red blood cells and your nerves. Vitamin B12 is also required to make DNA, which is a component of every one of your cells. The synthesis of fatty acids and amino acids, which make up fats and proteins, also relies on the presence of vitamin B12 in your body.

Daily Needs

The Food and Nutrition Board, which is a subgroup of the Institute of Medicine, set dietary recommendations for vitamin B12 based on age. From birth to the age of 6 months, infants require 0.4mcg of vitamin B12 daily. Infants between 7 months and 12 months require 0.5mcg of vitamin B12 daily. Toddlers between 1 and 3 should consume 0.9mcg of vitamin B12 every day and children between 4 and 8 should have 1.2mcg daily. Children between the ages of 9 and 13 require 1.8mcg per day. Adolescents and adults over the age of 14 should aim to consume 2.4mcg of vitamin B12 every day. Women who are pregnant should consume 2.6mcg and women who are lactating require 2.8mcg per day.

Food Sources

The natural form of vitamin B12 is found exclusively in animal foods, such as meat, poultry, fish and dairy products. Vegetarians can meet their vitamin B12 goals through sufficient intake of fortified cereals and soy milk. Fortified foods contain synthetic versions of vitamin B12, which in some cases may be more easily absorbed.

Deficiency and Toxicity

Because your body has the ability to store vitamin B12, deficiencies are rare. Most deficiencies occur because of an inability to properly absorb vitamin B12 due to underlying medical conditions. If a deficiency does develop, it can result in a number of physical symptoms, including fatigue, shortness of breath, nerve damage and difficulty walking, according to "Nutrition and You" by Joan Salge Blake.

There are no documented risks of consuming too much vitamin B12 either through dietary intake or supplementation. Because of this, no upper tolerable intake level has been set for vitamin B12.