The Benefits & Sources Of Vitamin B12

Vitamin B12 is a water-soluble vitamin, meaning that your body cannot store it; B12 needs to be replenished daily. It is naturally present in some animal products such as fish, meat, eggs and milk. You can also get B12 as a dietary supplement and a prescription medication, according to the Office of Dietary Supplements. The recommended daily allowance, or RDA, of vitamin B12 for adults is about 2.4 mcg.

Dietary

The best dietary sources for vitamin B12 are red meats such as braised beef liver, which offers 800 percent of the RDA of B12, according to the ODS, and sirloin beef; a variety of seafood such as trout, salmon and clams, each of which offers between 50 and 570 percent of the RDA of B12; dairy, including yogurt, milk, cheese and eggs; and chicken and ham. Generally, B12 is not present in plant foods. Therefore, vegetarians are encouraged to eat nonmeat, fortified foods or take a daily supplement to get the RDA of vitamin B12.

Fortified Foods

For those who do not eat foods with high concentrations of naturally occurring vitamin B12, and for those who do not eat animal products, foods fortified with B12 can provide your RDA of this B vitamin. The ODS reports that some breakfast cereals are fortified with between 25 and 100 percent of the RDA of B12. You can also consume energy bars, lunch meats, soy milk, tofu and bread fortified with the vitamin.

Prescription

Vitamin B12 injections are available by prescription. This type of B-vitamin supplementation is usually required for the treatment of B12 deficiency, and not for getting the recommended daily allowance.

Brain

Taking certain B vitamins, including B12, can reduce the rate of brain shrinkage in older folks by about half, according to a 2010 study by researchers at Oxford University. The two-year clinical trial found that about one in six elderly people older than 70 have some mild cognitive impairment, which manifests itself by problems with memory, language and other mental functions. Vitamin B12 is one of the B-vitamins that can control amino acid levels in the brain, which, when too high, can lead to an increased risk of Alzheimer's disease.

Blood

Pernicious anemia is a condition caused by a vitamin B12 deficiency. Anemia is a blood condition characterized by an insufficient number of red blood cells, which are responsible for carrying oxygen to all of the tissues in the body. Prior to the realization that B12 supplements help thwart this condition, a severe B12 deficiency was typically fatal, reports the National Heart, Lung and Blood Institute.