What to Eat When You Have Vitamin B12 Deficiency?

Written by Vicki Ma (Accredited Practising Dietitian and Sports Dietitian)

Vitamin B12 is one of the most important B vitamins. It plays a crucial role in the formation of red blood cells & maintaining normal brain function. B12 also works in conjunction with folate to produce DNA and is involved in the metabolism of body cells.  Who knew this vitamin could have such a BIG impact!

B12 is classified as an “essential” vitamin, which means it cannot be generated by our body and needs to be obtained from food sources or supplementation.

Symptoms of B12 deficiency 

As B12 can be stored in the liver for several years, the onset of a B12 deficiency is quite gradual and may take several years for symptoms to develop. As B12 is predominately found in animal based products, vegans are at risk of developing vitamin B12 deficiency.

Low levels of B12 in our blood can lead to megaloblastic anaemia. This is a condition where the red blood cells are larger than normal and are unable to carry oxygen around the body. Symptoms include pale skin, lethargy, shortness of breath, palpitations and weight loss. Long-term B12 deficiency can lead to irreversible nerve and brain damage.

How much B12 do we need? 

 Amount of Vitamin B12 (mcg)
Infant0.4 – 0.5 mcg
Children0.9 – 2.4 mcg
Men2.4 mcg
Female2.4 mcg
Pregnancy2.6 mcg
Lactation2.8 mcg

*source: NHMRC Nutrient Reference Values for Australia & New Zealand 2005. 

What foods have B12? 

Vitamin B12 is naturally found in animal products and is generally not present in plant-based foods, but can be found in fortified cereals, grains, soy milk as well as nutritional yeast. Foods such as mushrooms and fermentable soy products may have traces of B12 but this is not enough to meet the requirements.

Food SourcesVitamin B12 
Liver (Beef) – 100g83.1 mcg
Kidney (Lamb) – 100g52.2 mcg
Oysters – 100g17.6 mcg
Sardines – 100g8.9 mcg
Salmon – drained (100g)4.3 mcg
Lamb – 100g2.6 mcg
Beef – 100g1.8 mcg
Chicken – 100g0.4 mcg
Milk – 250 ml ( 1 cup)1.4 mcg
Yoghurt – 200g1.2 mcg
Fortified soy milk  – 250 ml ( 1 cup)1.0 mcg
Egg – 1 large0.8 mcg
Mushrooms – 100g0.04 mcg

*Source: Food Standards Australia New Zealand, NUTTAB 2010 online searchable database and Nutrition information Panels on Food Products


As you can see, having adequate levels of vitamin B12 is important not only for our physical health but also our mental health.

For more information regarding how to maintain your B12 levels, make sure to contact one of our Dietitians’ today!