Vitamin B12

This information has been reviewed and adapted for use in South Carolina by Janis G. Hunter, HGIC Nutrition Specialist, and Katherine L. Cason, Professor, State Program Leader for Food Safety and Nutrition, Clemson University. (New 07/07.)

HGIC 4078

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Why We Need It

Vitamin B12 works with folate, another B vitamin, to make DNA, which is the body's genetic material. Vitamin B12, a water-soluble vitamin, also protects nerve cells from damage and helps keep blood levels of the amino acid homocysteine low. This may help to decrease heart disease risk in some people.

Amounts Needed

Everyone needs vitamin B12. Older adults and strict vegetarians (vegans) should use fortified foods or supplements to ensure that they get enough.

Recommended Daily Intakes of Vitamin B12

Age Vitamin B12 (μg/day)

μg = micrograms

Source: adapted from the Dietary Reference Intakes series, National Academies Press. Copyright 1997, 1998, 2000, 2001, 2002, 2004, by the National Academies of Sciences.

birth-6 months
6 months-1 year
1-3 years
4-8 years
9-13 years
14 years and over
9-13 years
14 years and over




Vitamin B12 is found naturally only in foods of animal origin like meats, fish, poultry, eggs, and dairy foods. Older people often can not absorb vitamin B12from these foods. However, fortified breads and cereals contain vitamin B12 in a form that is easily absorbed. Check the ingredient list on food labels to see if vitamin B12 has been added. Here is a sample ingredient list from a fortified cereal:

INGREDIENTS: Wheat bran with other parts of wheat, sugar, raisins, whole wheat, partially hydrogenated soybean oil, corn syrup, brown sugar syrup, nonfat milk, salt, honey, vitamin C (sodium ascorbate), vitamin B2 (riboflavin), vitamin B1 (thiamin mononitrate), folic acid, vitamin B12

Sources of Vitamin B12
Food Vitamin B12
(μg per serving)

μg = micrograms
oz = ounces

oysters, cooked, 3 oz 30
beef, ground, extra lean, cooked, 3 oz 1.8
tuna, canned, 2 oz 1.6
fortified cereal, 1 serving 1.5
yogurt, plain, 8 oz 1.3
chicken, roasted, 3 oz 0.3

Ways to Retain It

Vitamin B12 is not easily destroyed by cooking. This is good to know, since the main food sources of vitamin B 12 (e.g. meat, fish, and poultry) need to be well cooked. Other sources, like fortified cereals, may not need cooking.

If We Don't Get Enough

Vitamin B12 deficiency causes pernicious anemia. This affects blood and nerves. With pernicious anemia, the body can't make normal red blood cells to carry oxygen in the blood. Lack of oxygen makes people weak and tired. Nerve damage can lead to paralysis and death.


If you don't get enough vitamin B12 from foods, you can take a multivitamin supplement. Strict vegetarians who do not eat fortified cereals or fortified soy foods need to take vitamin B12 in a supplement. In addition, older adults often do not absorb vitamin B12 very well. If they don't get adequate B12 from fortified foods, they need a supplement, also.

For More Information

The Family and Consumer Sciences (FCS) agent at your county Extension office may have more written information and nutrition classes for you to attend. Also, your doctor, health care provider, or a registered dietitian (RD) can provide reliable information.

Reliable nutrition information may be found on the Internet at the following sites:


  1. Bobroff, Linda B. University of Florida Extension. Facts About Vitamin B12 . FCS8701. April 2006.
  2. National Academies of Sciences. National Academies Press. Dietary Reference Intakes series. 2004.
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