Vitamin B-12

What is vitamin B-12?

Vitamin B-12 is an important vitamin that you usually get from your food. It is mainly found in meat and dairy products. Vitamin B-12 helps make red blood cells and keeps your nervous system working properly.

Vegetarians who do not eat meat or dairy products are at risk for low vitamin B-12 usually about 2 years after they become vegetarians. However, most people who have low vitamin B-12 are not strict vegetarians. Most people with low vitamin B-12 levels have trouble absorbing vitamin B-12 from their stomach or small intestines.

What happens if my vitamin B-12 level is low?

You might not have any symptoms if your vitamin B-12 level is just a little bit low. However, a very low vitamin B-12 level can cause anemia, depression, dementia or a serious problem with your nervous system.

Some people with low vitamin B-12 also have high levels of homocysteine (say: "ho-mo-sis-teen"), an amino acid (a building block of protein) in the blood. If you have both of these problems, you may have a higher risk of heart disease and stroke.

What can cause problems with absorbing vitamin B-12?

The following are some things that can cause problems with absorbing vitamin B-12:

• If you have a disease called pernicious anemia (say: "per-nish-us ah-nee-mee-ah"), it can destroy the cells in your stomach that help you absorb vitamin B-12.
• If you use medicine for heartburn and ulcers for a long time, you may have trouble absorbing vitamin B-12. 
• If you have had surgery on your stomach or your intestines, you may have trouble absorbing vitamin B-12.

Your doctor will find out why you have a low vitamin B-12 level by asking questions about your health, giving you a physical exam and checking your blood, if necessary.

Can I just take one multivitamin pill every day to raise a low vitamin B-12 level?

No. Over-the-counter multivitamins do not contain enough vitamin B-12 to raise a low level. To get enough vitamin B-12, you will need to take special vitamin B-12 pills.

You can also get shots of vitamin B-12. Usually, these shots are given every 1 to 2 days for about 2 weeks. After this, a shot is given once every month. Your doctor can help decide whether pills or shots are right for you.

How long will I have to take Vitamin B-12 pills or get the shots?

Most people with low vitamin B-12 take the pills or get the shots for the rest of their lives.

Other Organizations

National Institutes of Health Facts About Dietary Supplements
http://ods.od.nih.gov/factsheets/cc/vitb12.html

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