Vitamin B12 is a naturally occurring substance found in some foods that is also available as a dietary supplement. Your body uses vitamin B12 to help form red blood cells, synthesize DNA, and promote neurological function.1
This water-soluble vitamin is found in animal products like organ meats, shellfish, eggs, and milk. You can also find it in fortified cereals and plant products, though it is not naturally occurring in plants. Non-animal sources of vitamin B12 are not considered a reliable source of this vitamin, which means that vegetarians and vegans may have to supplement with multivitamins or other sources to get enough vitamin B12 in their diet. Individuals over the age of 50, people who have digestive disorders, and people who have had gastrointestinal surgery may have a difficult time absorbing vitamin B12 and may benefit from a supplement.2
Vitamin B12 deficiencies can lead to a form of anemia called vitamin B12 deficiency anemia. This occurs when vitamin B12 levels are low in the body and can’t make as much red blood cells as the body needs. This can make you feel tired and weak as well as affect memory and nerve function. Vitamin B12 deficiencies can also cause numbness in the extremities, weakness and loss of balance.2,3
Vitamin B12 Uses and Health Benefits
Vitamin B12 benefits many body processes. Among vitamin B12 uses as a supplement, it can help with:
- Canker Sores - Vitamin B12 deficiencies are thought to be one cause for canker sores. One study found that individuals taking B vitamin supplements twice daily for six months saw fewer canker sores even when they weren’t deficient in B vitamins. Other vitamin B supplements like vitamin B1, B2, and B6 pair well with a vitamin B12 supplement for preventing canker sores.
- Asthma - Vitamin B12 deficiencies may be related to mystery coughs, and supplements can help cure the cough. It’s believed that this type of cough may be related to asthma, so a vitamin B12 diet supplement may help reduce asthma symptoms.
- Restless Leg Syndrome - Vitamin B12 deficiencies are thought to be linked to restless leg syndrome. Taking oral supplements may help individuals with this condition.
- Age-Related Macular Degeneration (ARMD) - Age-related macular degeneration is a condition of the eye that commonly causes vision loss in older adults. One double-blind study found that daily supplements of vitamin B12, vitamin B6, and folic acid helped decrease this problem in females with high risk for ARMD.
Vitamin B12 Side Effects and Precautions
Vitamin B12 is considered safe.8 When you intake more than your body needs, it simply expels the rest through urine. Individuals who take antibiotics, drink an excessive amount of alcohol, or use stomach-acid controlling drugs may have problems with vitamin B12 absorption. Potassium and vitamin C supplements may also affect absorption. Talk to your doctor if you’re taking other medications, are pregnant or breastfeeding, or if you feel you’re not getting enough vitamin B12 in your diet.