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HealthInfo Waitaha Canterbury

Eating well to prevent vitamin B12 deficiency

Te kainga pai e ārai ai i te korenga huaora B12

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.

Causes of 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 cannot absorb the vitamin. This can happen if any of the following apply.

Vitamin B12 deficiency can also happen if you do not 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 cannot treat vitamin B12 deficiency by diet alone. So, if you're low in vitamin B12, your general practice team will recommend vitamin B12 treatment.

How you replace your stores of vitamin B12 depend on why your vitamin B12 level is low. If you're low in vitamin B12 because your body cannot absorb it from food, you may need vitamin B12 injections. High-dose vitamin B12 tablets are an option for some people, although they aren't 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. But some people need ongoing vitamin B12 treatment. Discuss this with your general practice team.

Foods that 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 cannot absorb.

If you're 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

Vitamin B12 dietary supplements

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

Some people claim that Spirulina is a good source of vitamin B12. But it's in a form that is inactive or your body cannot absorb.

Your general practice team, dietitian or pharmacist can tell you what the most appropriate supplement is for you.

Written by HealthInfo clinical advisers. Last reviewed February 2023.


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