Gold Member Badge


  • You're all caught up!

Is 500 mg of B12 Too Much to Take?

author image Amanda Lynch
Amanda Lynch has been writing professionally for print and online publications since 2000. With a master's degree in health communication, her background includes patient counseling, community health and script development. Lynch specializes in covering topics related to health and wellness, women's issues and parenting.
Is 500 mg of B12 Too Much to Take?
Oysters are rich in vitamin B12.

Vitamin B12 is a water-soluble vitamin in the B-complex of vitamins. Most people obtain adequate vitamin B12 from the foods they eat, but some people still choose to supplement, or your doctor may recommend a supplement. Unlike some vitamins, vitamin B12 is measured in micrograms, not milligrams. A micrograms is a thousandth of a milligram, so 500 mg of vitamin B12 is 500,000 micrograms; the recommended daily intake is between 2 and 2.8 micrograms.

Video of the Day

Overview of Vitamin B12

The body uses vitamin B12, along with the B-complex vitamin folate, to help produce DNA. B12 also helps to keep levels of some amino acids stable and to prevent damage to your nerve cells. Found primarily in animal products such as fish, poultry, eggs, milk and other dairy products, B12 is also used to enrich some grain products. According to the University of Florida, adults who are not pregnant or breastfeeding require 2.4 micrograms of B12 a day, while pregnant women should get 2.6 micrograms and women who are breastfeeding should get 2.8 micrograms. You usually can get these amounts in your daily diet.

Vitamin B12 Deficiency

While vitamin B12 deficiency is generally rare in healthy adults, occasionally strict vegetarians, older adults or people whose bodies do not properly process vitamin B12 may suffer from a deficiency. According to the National Institutes of Health, situations in which your physician may check to see if you have a vitamin B12 deficiency include when another condition called megaloblastic anemia is suspected, if you have been suffering from delirium or dementia, if you suffer from a disorder like celiac or Crohn's disease, or sometimes if you are pregnant. Vitamin B12 deficiency is usually treated by supplements of B12, either in pill form or as injections.

Vitamin B12 and Anemia

A deficiency of vitamin B12 can contribute to your developing a type of anemia called megaloblastic or pernicious anemia. Because vitamin B12 is used in the production of red blood cells and the maintenance of the nervous system, a lack of B12 can cause your body to manufacture inadequate red blood cells. Pernicious anemia may have no symptoms and occurs most frequently in people who suffer either from an autoimmune disorder or who have a disease of malabsorption that prevents their bodies from absorbing enough vitamin B12. Treatment for this type of anemia depends on its severity, but usually involves B12 supplements.

Contraindications of Vitamin B12

While vitamin B12 is naturally found in many foods, there are some situations in which you should not take supplements or high doses of vitamin B12. If you have Leber's disease, large doses of vitamin B12 could lead to damage in your optic nerve and even blindness. If you have an allergy to cobalt, you should avoid vitamin B12 supplements until you have discussed it with your physician. Let your doctor know if you are pregnant or breastfeeding, and discuss any other medications or supplements you are taking.

LiveStrong Calorie Tracker
Lose Weight. Feel Great! Change your life with MyPlate by LIVESTRONG.COM
  • Gain 2 pounds per week
  • Gain 1.5 pounds per week
  • Gain 1 pound per week
  • Gain 0.5 pound per week
  • Maintain my current weight
  • Lose 0.5 pound per week
  • Lose 1 pound per week
  • Lose 1.5 pounds per week
  • Lose 2 pounds per week
  • Female
  • Male
ft. in.



Demand Media