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Vitamin B12 Vitamin B12 Definition Vitamin B12

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					Vitamin B12
Definition



Vitamin B12 is a water-soluble vitamin. Water-soluble vitamins dissolve in water.
After the body uses these vitamins, leftover amounts leave the body through the urine.
Typically, water-soluble vitamins can not be stored by the body. Vitamin B12 is
special, because the body can store it for years in the liver.


Overview & Functions

Vitamin B12, 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

.

Food Sources

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




Recommendations

The Food and Nutrition Board at the Institute of Medicine recommends the following
dietary intake for vitamin B 12:
Infants

       0 - 6 months: 0.4 micrograms per day (mcg/day)
       7 - 12 months: 0.5 mcg/day

Children

       1 - 3 years: 0.9 mcg/day
       4 - 8 years: 1.2 mcg/day
       9 - 13 years: 1.8 mcg/day


Adolescents and Adults

       Males and females age 14 and older: 2.4 mcg/day

Specific recommendations depend on age, gender, and other factors (such as
pregnancy). Women who are pregnant or producing breast milk (lactating) need
higher amounts. Ask your health care provider which amount is best for you.
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.
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 vitamin B12 from the
intestinal tract.
Because vitamin B12 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 vitamin B12 exist but are highly
variable in their B12 content. They are considered unreliable sources of the vitamin.)


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.



References

Rakel D, ed. Integrative Medicine. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2007.
Hamrick I, Counts SH. Vitamin and mineral supplements. Wellness and Prevention.
December 2008:35(4);729-747.
Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L,
Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;
2007:chap 237.




                              Vitamin B12 benefits
Vitamin B12 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.


                              Vitamin B12 source




                                                       The human body
 stores several years' worth of vitamin B12, so nutritional deficiency of
   this vitamin is extremely rare. Although, people who follow a strict
vegetarian diet and do not consume eggs or dairy products may require
                        vitamin B12 supplements.

				
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Description: Definition Vitamin B12 is a water-soluble vitamin. Water-soluble vitamins dissolve in water. After the body uses these vitamins, leftover amounts leave the body through the urine. Typically, water-soluble vitamins can not be stored by the body. Vitamin B12 is special, because the body can store it for years in the liver.