The Importance of Vitamin B12

Written by
Alannah Mezzatesta, BSc
Nutrition Scientist (ANutr)
last updated  27th July 2022

 

Vitamin B12 is an essential vitamin as we lack the ability to produce it ourselves and therefore must obtain it from our diet. It plays a very important role in the body as it required for proper brain function, nerve tissue health and production of red blood cells [3257642] [9930567] [23193625].

Vitamin B12 deficiency* is a common global health concern with the potential to cause severe health complications including cardiovascular disease [9509248], neural tube defects [7564788], and dementia and Alzheimer?s disease [11844848]. Symptoms are widespread and can include: fatigue, depression, weakness, weight loss, loss of appetite, numbness and tingling in the hands and feet, confusion, poor memory, and trouble maintaining balance [9155210].

Furthermore, a recent preliminary study [26960786] has established a link between vitamin B12 deficiency and chronic tinnitus which is described as a persistent ringing, or buzzing in the ears. Severity of symptoms improved significantly after 6 weeks of treatment with vitamin B12 supplements suggesting that vitamin B12 may play a therapeutic role in deficient patients suffering from chronic tinnitus.

Preventing deficiency is therefore crucial to help maintain optimum health and can be done through consumption of a healthy, well balanced diet.

 

Where can I get vitamin B12 from?

The majority of vitamin B12 is sourced from animal-based foods** such as meat, dairy and eggs, however, several plant-based foods naturally containing substantial amounts of vitamin B12 provide a suitable alternative for vegans and vegetarians. These foods include: tempeh (0.7?8.0 ?g/100 g); certain types of mushrooms such as dried shiitake (5.61 ?g/100 g) and certain types of edible dried seaweed such as green laver and purple laver (63.6 ?g/100 g and 32.3 ?g /100g, respectively). Additionally, there is evidence to suggest that plants grown using organic fertilisers (i.e. cow manure) instead of chemical fertilisers contained a higher amount of vitamin B12 [24803097].

As these foods are relatively limited, fortified foods such as nutritional yeast, soy milk, yeast spreads, or soy-based meat products are highly recommended in order to obtain enough vitamin B12. Vitamin B12 supplements are often not the ideal choice as many supplements on the market contain excipients which may have adverse effects on your health [32327401] [33153099].

 

Storage is important

If you do decide to go down the supplements pathway, take care to store them correctly as vitamin B12 is water-soluble and is sensitive to light and oxygen, and will begin to degrade if stored for a long time. This applies to cooking methods too; meats cooked for a long time and/or at high temperatures show a lower vitamin B12 content than slow/low temperature cooking [22062483]. However, this may in part be due to the water loss associated with cooking rather than the temperature itself.

It's always worth asking your healthcare professional for a blood test to check your vitamin B12 levels.

*The cut off level for determining vitamin B12 deficiency is usually <220pmol/L [25369926]. In Australia, the recommended dietary intake for men and women over 14 years old is 2.4 Êg per day, as set by the NHMRC.

**Vitamin B12 content can vary depending on the source of these foods as cobalt deficiency in the soil of certain grazing areas in Australia and other parts of the world can cause vitamin B12 deficiency in cattle and sheep flocks. In these circumstances, animals are given vitamin B12 supplements.