What foods contain B12?
Vitamin B12 is found in foods from animals, such as meat, seafood, milk products, poultry, and eggs. It is not in foods from plants unless it has been added to the food (fortified). Some foods, like cereals, are fortified with vitamin B12.
Supplements containing only B12, or B12 along with other B vitamins and/or folate, are readily available. Also, B12 is usually in multivitamins. Check the label to find out how much B12 is in a supplement.
Estimates of B12 in certain foods2
| Food|| Serving size|| B12 amount (microgram)|
|Beef liver||3 ounces||71 mcg|
|Clams||3 ounces||84 mcg|
|Cereal fortified with 100% daily value for B12 ||1 serving||6 mcg|
|Rainbow trout||3 ounces||3 mcg|
|Nonfat plain yogurt||8 ounces||1 mcg|
|Large egg||1 egg||½ mcg|
|Chicken breast||½ breast||½ mcg|
What are the symptoms?
If your vitamin B12
deficiency is mild, you may not have symptoms or you may not notice them. Some
people may think they are just the result of growing older. As the anemia gets
worse, you may:
- Feel weak, tired, and lightheaded.
- Have pale skin.
- Have a sore, red tongue or bleeding
- Feel sick to your stomach and lose weight.
Have diarrhea or constipation.
If the level of vitamin B12 stays low for a long time, it
can damage your nerve cells. If this happens, you may have:
- Numbness or tingling in your fingers and
- A poor sense of balance.
- Dementia, a loss of mental abilities.
How is vitamin B12 deficiency anemia diagnosed?
Your doctor will examine you and ask questions about your past health and
how you are feeling now. You will also have blood tests to check the number of
red blood cells and to see if your body has enough vitamin B12.
The level of
folic acid, another B vitamin, will be checked too.
Some people whose vitamin B12 levels are too low also have low levels of folic
acid. The two problems can cause similar symptoms. But they are treated differently.