Vitamin B12 is essential for the blood, brain and nervous system. Not having enough in the body can cause people to feel tired and sick. Eating more meat and animal products can boost levels of vitamin B12. If you don’t eat meat, however, taking vitamin B12 supplements may be an option.

Why is vitamin B12 important for health?

The body uses vitamin B12 to make red blood cells and to repair body tissue. It's also important for the health of nerves.

If you don't have sufficient vitamin B12, this can lead to a type of anaemia, meaning you don't have enough red blood cells in your blood. You might also be at risk of neuropathy, meaning you have nerve damage that causes tingling and numbness in your hands and feet.

Symptoms of vitamin B12 deficiency include tiredness, light-headedness, a rapid heart rate, bruising easily and bleeding, weight loss, bowel upsets and a sore tongue. If you have B12 deficiency, you may need to change your diet, or you may need supplements, taken either as tablets or by injection.

What are the best sources of vitamin B12?

The best source of vitamin B12 is animal products, including meat and dairy.

Australian Dietary Guidelines recommend you eat 1 to 3 serves a day of lean meat, poultry, fish or eggs, depending on your age and gender. The guidelines also recommend 1 to 4 serves of dairy a day, depending on your age and gender.

You can get vitamin B12 from the following foods:

• clams
• mussels
• crab
• salmon
• beef
• chicken
• eggs (whole)
• milk

Most Australians get more than enough vitamin B12 in their normal diets. If you eat more than you need, it's stored in your liver and can be used later.

Vegetarians can get enough vitamin B12 from dairy foods and eggs. It used to be thought that plant foods such as mushrooms, spirulina, tempeh and miso contained vitamin B12, but this is not correct.

The only way for vegans to get enough is by eating foods fortified with vitamin B12 or by taking a supplement. Foods in Australia that are fortified with vitamin B12 include some soy milks, yeast spread, and vegetarian meat substitutes such as soy-based burgers and sausages.

Should I take vitamin B12 supplements?

You should talk to your doctor about taking a vitamin B12 supplement if you don't have enough B12 in your diet — for example, if you are vegan or avoiding animal foods. It is very important for pregnant or breastfeeding vegan and vegetarian women to have enough vitamin B12 to reduce the risk of their baby developing a vitamin B12 deficiency.

You might also need a supplement if you can't absorb enough vitamin B12 from food if, for example, you have a problem with your gut or an autoimmune condition. Your doctor can order a blood test to see if you have enough B12 in your body.