Some people claim that vitamin B-12 will boost your:

  • energy
  • concentration
  • memory
  • mood

However, when speaking before Congress in 2008, Susan B. Shurin, M.D., deputy director of the National Heart, Lung, and Blood Institute, countered these claims. She testified that vitamin B-12 could do all of these things for people who are deficient in the vitamin. However, no clinical evidence suggests that it can boost energy in people who already have ample stores of it.

Vitamin B-12, or cobalamin, is a nutrient you need for good health. It’s one of eight B vitamins that help the body convert the food you eat into glucose, which gives you energy. Vitamin B-12 has a number of additional functions. You need it for the:

  • production of elements of DNA
  • production of red blood cells
  • regeneration of bone marrow and the lining of the gastrointestinal and respiratory tracts
  • health of your nervous system, which includes your spinal cord
  • prevention of megaloblastic anemia

The amount of vitamin B-12 you need is primarily based on your age. The average recommended daily amounts of vitamin B-12 are:

  • birth to 6 months old: 0.4 micrograms (mcg)
  • 7-12 months: 0.5 mcg
  • 1-3 years: 0.9 mcg
  • 4-8 years: 1.2 mcg
  • 9-13 years: 1.8 mcg
  • 14-18 years: 2.4 mcg
  • 19 and older: 2.4 mcg
  • pregnant teens and women: 2.6 mcg
  • breast-feeding teens and women: 2.8 mcg

Vitamin B-12 is naturally in foods that come from animals, including:

  • meat
  • fish
  • eggs
  • dairy products

It also may be in some fortified cereals and nutritional yeast.

Although most Americans get enough vitamin B-12, some people are at an increased risk of vitamin B-12 deficiency, particularly those who:

The symptoms of vitamin B-12 deficiency include:

The most serious condition associated with vitamin B-12 deficiency is megaloblastic anemia. This is a chronic blood disorder in which the bone marrow produces overly large, immature blood cells. As a result, the body doesn’t have enough healthy red blood cells to carry oxygen around the body.

Older adults are in the age group that’s most likely to be deficient in vitamin B-12. As you age, your digestive system doesn’t produce as much acid. This reduces your body’s ability to absorb vitamin B-12.

The National Health and Nutrition Examination Survey found that more than 3 percent of adults over age 50 have seriously low levels of vitamin B-12. The survey also says that up to 20 percent of older adults may have borderline levels of vitamin B-12.

Evidence indicates that vitamin B-12 has many benefits for people as they age. It can:

You should be aware of vitamin B-12 in your diet, but you don’t need to be overly concerned about if you’re not in an at-risk group. As with most nutrients, it’s best if you can get the vitamin B-12 you need from the food you eat. For ample stores of vitamin B-12, eat a well-rounded diet that includes:

A simple blood test can determine the B-12 levels in your body. If your stores are low, your doctor may prescribe a supplement. Supplemental vitamin B-12 is available in pill form, in tablets that dissolve under the tongue, and in a gel that you apply to the inside of your nostrils. In some cases, your doctor may recommend using injections to increase your vitamin B-12 levels.