Tired all the time? Superstar vitamin B12 can help

This year, for the first time, the National Institute for Health and Care Excellence (Nice) has issued draft guidelines on vitamin B12 deficiency. As many as one in 10 over-75s (and one in 20 people aged between 60 and 74) could be experiencing fatigue, cognitive impairment and mental health issues, such as anxiety. 

There is a fair chance that these could be a result of not consuming enough B12-rich foods, which are primarily found in animal products such as meat, fish and eggs. Those with vegan diets are also at risk.

Nice suggests that those with one symptom and one risk factor – such as a plant-only diet – should be offered a blood test by their GP, in order to diagnose whether they are vitamin B12-deficient. They believe that the guidelines, which are now subject to a six-week consultation, will “improve diagnosis and management, reduce complications and improve quality of life for patients with suspected and confirmed deficiency”. 

Here’s what you need to know.

What is vitamin B12?

Vitamin B12 is required to form red blood cells and DNA, as well as assisting in the development and function of brain and nerve cells. “To get enough vitamin B12, your body needs a protein called intrinsic factor,” explains Karina Antram, a nutritionist and the author of Fix Your Fatigue. “This protein is made by your stomach lining [and] it allows you to absorb vitamin B12 from the food you eat.”

Where is it found?

Fish, meat, dairy products and eggs are all vitamin B12-rich, as are some fortified cereals and Marmite.

What are the signs of deficiency?

Symptoms include brain fog and tiredness, headaches, diarrhoea, blurred vision, mouth ulcers, muscle weakness; psychological problems range from mild depression to severe confusion. 

Heidi Seage, the principal lecturer in health psychology at Cardiff Metropolitan University, recently held a workshop, which revealed that very few of the older adults involved had thought about their own risk of vitamin B12 deficiency. “I don’t think it’s understood as a condition that adults might be more at risk of getting as they age,” she says.

Seage believes that the likes of brain fog and fatigue in particular, which “come on gradually and are quite insidious”, are wrongly put down to natural ageing, rather than signs of fast-diminishing B12 levels (which should be around 3mg for a healthy person). This prevents people from seeking guidance from their GP as they should.

Who else can be affected? 

“Limited dietary intake, malabsorption of vitamin B12 in the bloodstream, medical conditions, or the use of B12-depleting medications can result in deficiencies among the general population,” says Antram. 

Pernicious anaemia, an autoimmune condition affecting the stomach, is the most common cause of vitamin B12 deficiency in the UK. Other stomach and small intestine disorders such as Crohn’s disease, which causes inflammation of the digestive system’s lining, may limit the required absorption of vitamin B12 from food.

What’s the next step?

Discuss your symptoms with your GP. If they suspect it’s vitamin B12 deficiency, they can order a serum test to assess the levels of B12 in your bloodstream (though the accuracy of these has been subject to debate). Nice advises that high levels of methylmalonic acid in the blood, which the body produces when it is low on B12, “should be used to confirm diagnosis, if initial testing is inconclusive”.

How can you boost your levels?

If you’re non-vegetarian, the first thing to do is try and up your meat intake. Vitamin B12 is also available in multivitamin and mineral supplements at pharmacies. For the severely deficient, injections – which are typically 1,000 micrograms and can be obtained via the NHS, or at a private clinic – are more effective.

How long does it take to restore levels after deficiency?

This depends on “various factors”, according to Antram. “Most people find that they have adequate levels after a few months to a year of B12 treatment. It’s worth retesting your levels again after three months.”

Can you have too much B12?

“The B12 that isn’t being used within your body’s systems gets flushed out in urine,” says Seage. “So the body absorbing too high a level is unlikely.”