Vitamin B-12, also known as cobalamin, is important for maintaining a healthy metabolism and central nervous system. This vitamin is present in many foods, including eggs, meat, poultry, shellfish, milk and fortified cereals. Unlike other vitamins in the B family that are water soluble and pass through your body quickly, vitamin B-12 can be stored in your liver for years.
Vitamin B-12's primary function is to aid in metabolism, the process by which your body creates and uses energy. B-12 helps regulate digestion, absorption, respiration, circulation and body temperature, according to the University of Maryland Medical Center, or UMMC. When combined with folate and vitamin B-6, vitamin B-12 might help reduce your risk of breast cancer, states the Memorial Sloan-Kettering Cancer Center. The vitamin is also beneficial for certain cardiovascular disorders, fatigue and restless leg syndrome. Your doctor may prescribe B-12 injections If you have pernicious anemia.
Food Sources of B-12
Animal foods such as meat, eggs and diary are good sources of cobalamin, states the National Institutes of Health. Seafood scores particularly high in vitamin B-12, with clams, oysters, crab, salmon and sardines topping the list. Turkey, beef and chicken, including organ meat, are rich in B-12. Vegans are at risk for a vitamin B-12 deficiency, as they avoid animal foods.
If you regularly consume meat and dairy products, you probably don't need to take B-12 supplements, says the UMMC. If you are an older adult, however, you may need to supplement the vitamin, as your ability to absorb B-12 decreases as you age and when you take antacid medications. Consider taking a B-complex supplement, as taking individual B-vitamins may result in an imbalance of the others in the B family, cautions the UMMC. Vitamin B-12 supplements may interact with certain medications, such as tetracycline. Consult your doctor before supplementing B-12.
Vitamin B-12 Deficiency
In addition to vegans and the elderly, other populations are at risk for vitamin B-12 deficiency, says the UMMC. People with eating disorders, HIV, and conditions such as a tapeworm infection or small intestine or stomach surgery, which make it difficult for the body to absorb vitamin B12. When your stomach cannot manufacture enough intrinsic factor, you cannot absorb vitamin B12, which results in a condition called pernicious anemia. Vitamin B12 deficiency is characterized by tiredness, shortness of breath, nervousness, diarrhea and numbness or tingling in the extremities.
Daily B-12 Requirements
Your daily B-12 requirement is set by the Food and Nutrition Board of the Institutes of Medicine. Male and female adults need 2.4 micrograms of vitamin B-12 daily. Talk to your doctor if you suspect that your diet does not meet your B-12 needs.