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HealthInfo Canterbury

Eating well to prevent vitamin B12 deficiency

Vitamin B12 helps keep your body's nerve and blood cells healthy. It helps make DNA, the genetic material in your cells. It also helps prevent a type of anaemia that can make you feel tired and weak.

What causes vitamin B12 deficiency?

Normally, your stomach and intestines digest and absorb vitamin B12 from your food. Vitamin B12 deficiency happens when your stomach and intestines can't absorb the vitamin. This can happen if any of the following apply.

Vitamin B12 deficiency can also happen if you don't eat enough foods with vitamin B12. Most people in New Zealand get plenty of vitamin B12 from food. But some people might not get enough. These people include:

Treating vitamin B12 deficiency

Vitamin B12 deficiency is diagnosed through a blood test. You can't treat vitamin B12 deficiency by diet alone. So if you are low in vitamin B12, your doctor will recommend vitamin B12 treatment.

How you replace your stores of vitamin B12 will depend on why your vitamin B12 level is low. If you are low in vitamin B12 because your body can't absorb it from food, you may need vitamin B12 injections. High-dose vitamin B12 tablets are an option for some people, although they are not publicly funded. These tablets provide a much higher dose of vitamin B12 than the standard vitamin supplements you can buy from a pharmacy or health food store.

When your vitamin B12 level is back to normal you may be able to stop the treatment. Although some people need ongoing vitamin B12 treatment. Discuss this with your doctor.

What foods contain vitamin B12?

Other plant foods including grains, fruit and vegetables do not contain vitamin B12. Some people claim that seaweed, algae and fermented food such as tempeh contain vitamin B12. But these foods usually contain a form of vitamin B12 that our bodies can't absorb.

If you are 65 or older, your body will absorb the vitamin B12 added to fortified foods more easily than the vitamin B12 found in foods naturally.

How to get your daily vitamin B12 from food

What kinds of vitamin B12 dietary supplements are available?

These supplements are only suitable for maintaining vitamin B12 levels in people who can't get enough vitamin B12 from food. They are not suitable for treating vitamin B12 deficiency.

Your doctor or pharmacist can tell you what the most appropriate supplement is for you.

Written by HealthInfo clinical advisers. Last reviewed October 2018.


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