B12's been getting a lot of attention of late, particularly due to the growing movement of people following a plant based diet. However, there's some misunderstanding around sourcing and absorbing this essential vitamin.

WHAT'S THE BIG DEAL ABOUT B12?

A combination of B12 and folate are vital for synthesis of DNA and red blood cells. B12 is also essential in both the production of myelin sheaths which surround nerves and in the conduction of nerve impulses themselves. 

Pretty damn important right?!

What's more, the body cannot synthesise B12 so it's essential that we obtain it either from food or supplementation. 

WHICH FOOD CONTAINS B12?

Bioavailable B12 can only be sourced from animal protein. There is a common misconception that you can obtain B12 from seaweed, spirulina and fermented soy, but these only contain B12 analogs called 'cobamides' which actually block intake of B12.  

B12 contains the trace element cobalt (hence B12 is known as a cobalamin) which is produced in the guts of animals, it's the only vitamin that we can't obtain from plants or sunlight. So if you're on a plant based diet.... B12 supplementation is crucial, methylcobalamin being the most effective as it bypasses several potential issues in the absorption cycle.

The most nutrient dense sources of B12 are organ meat, liver in particular, and shell fish (eg clams and oysters), these offer the biggest bang for your buck. You will also find it in fish eggs, crab, beef, lamb, octopus, lobster, eggs and cheese.   

CAN YOU BE DEFICIENT IN B12 EVEN ON A HEALTHY DIET?

Yes, unfortunately consuming nutrient dense animal protein or supplementing with B12 does not guarantee optimal levels. Digestive disorders such as coeliac, crohns or ulcerative colitis impair absorption, as can:

- Pernicious anaemia

- Intestinal dysbiosis or leaky gut

- Low levels of stomach acid

- Alcohol

- Medications such as antibiotics, metformin, proton-pump inhibitors 

- Exposure to nitrous oxide (surgical or recreational)

To avoid malabsorption, B12 injections (which would have to be prescribed by your GP) or oral/nasal administration are recommended. 

SO WHAT SYMPTOMS MIGHT BE EXPERIENCED WITH B12 DEFICIENCY?:

- Fatigue

- Legarthy

- Weakness

- Memory loss

- Neurological problems

- Disturbed vision

- Mouth ulcers

- Breathlessness

- Headaches

- Pale skin

- Tinnitus

- Palpitations

To name but a few....

WHAT CAN WE DO TO ENSURE ADEQUATE LEVELS OF B12?

Given how nutrient deprived our diets tend to be in the Western world, it's crucial to make sure you are including either a good source of nutrient dense animal protein if your diet, or supplementing accordingly. It may also be worth getting your B12 levels checked. 

Hope this has helped shed some light on the issues around sourcing and absorbing this elusive vitamin. 

The content in this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding your health.