Struggling to stay awake? You could need more vitamin B12!

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Qualified Nutritionist (BSc, MSc, RNutr)
Ask Emma

28 November 2017

What does vitamin B12 do for your body?

Vitamin B12, sometimes known as cobalamin, serves a number of functions within the body, helping with everything from maintaining healthy nerve cells to supporting your formation of red blood cells. As with all B vitamins, vitamin B12 is involved with converting carbohydrates into glucose, one of your body’s primary energy sources.

Vitamin B12 also has a close relationship with vitamin B9, also known as folate, and the two are often linked to metabolism, helping to convert dangerous homocysteine, a naturally occurring amino acid, into methionine. B12 is also responsible for reactivating folic acid and converting it into a form which can then be used by the body – this is why low levels of vitamin B12 are often associated with low levels of folic acid.1

Here are just a few of the other functions vitamin B12 is involved in:

  • Supports your cardiovascular system
  • Boosts your mood
  • Helps to maintain healthy cognitive function
  • Essential for healthy DNA

So how much vitamin B12 should you be getting?

Although the daily recommendation for B12 is lower than other B vitamins, your body cannot synthesise vitamin B12 so you intake it from food sources. The general recommendation for adults is around 1.5-2.4mcg.


What happens when you’re not getting enough

Okay, so vitamin B12 is pretty essential for a variety of bodily functions, however, it’s estimated that around 6 million in the UK alone are deficient, including 20% of those over the age of 60!2 So what happens if you’re not getting enough?

Low levels of vitamin B12 are associated with a number of symptoms so below, I’ll just cover a few of the more common ones to give you an idea of what you should be looking out for.

  • Fatigue
  • Dizziness
  • Breathlessness
  • Memory fog
  • Mood swings
  • Pins and needles
  • Sore muscles
  • Lack of appetite

A few of these symptoms, such as fatigue and dizziness, are connected to vitamin B12’s role in the formation of red blood cells. If an insufficient amount of red blood cells are produced then oxygen won’t be transported around your body as efficiently, meaning areas such as your muscles will feel weaker and you’ll generally feel tired and lethargic.

When it comes to symptoms like mood swings, vitamins B12’s role in synthesising certain brain chemicals comes to the forefront, particularly serotonin and dopamine, which are important for maintaining your mood. Without vitamin B12, your body’s production of myelin, a fatty substance that insulates your nerves, is different which can result in the sensation of pins and needles.


Who's at risk of developing a deficiency?

Vitamin B12, as I mentioned earlier, is only needed in small quantities by the body so for most people, a deficiency in B12 is unlikely, however, there are certain groups of people that can be more vulnerable to low levels of vitamin B12 than others, either because they aren’t getting enough in their diet or they struggle to absorb it in their body.

Over 50’s

Unfortunately, if you are over 50, you may be more predisposed to low levels of vitamin B12 for a number of reasons. As you age, your levels of stomach acid gradually decrease; making it more difficult for you break down food meaning that vitamin B12 is not as efficiently absorbed. It’s estimated that around 10-15% of over 60s are deficient in vitamin B12.

Vegans and vegetarians

In most instances, getting enough vitamin B12 from your diet isn’t a problem but if you’re vegan or vegetarian you may find it a bit tricky. This is because vitamin B12 is normally found in animal- derived products such as meat, dairy and eggs.

Those on certain medications

Certain medications for diabetes or acid reflux can prevent you from properly absorbing vitamin B12 from your food. Metformin, PPIs, long-term antibiotics or antacids can all inhibit your ability to absorb vitamin B12.


If you’ve had weight-loss surgery or any procedure to remove part of the stomach it can result in a vitamin B12 deficiency.

Bacterial overgrowth
An overgrowth of unfriendly intestinal bacteria can prevent vitamin B12 from being properly absorbed by the body, as is the case in some illnesses such as diabetes or diverticula.


If you suffer from hypothyroidism you may be more vulnerable to low levels of vitamin B12. According to one study, which monitored the vitamin B12 levels of 116 hypothyroid patients, approximately 40% were found to be deficient in vitamin B12,4  implying that there is a connection between the two conditions.

Digestive disorders

Digestive disorders such as coeliac disease or Crohn’s syndrome can make it more difficult for your body to absorb vitamin B12, and over a long period of time, this may eventually lead to a deficiency.



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What about pernicious anaemia?

You may have heard of pernicious anaemia, arguably the most common cause of vitamin B12 deficiency. Pernicious anaemia occurs when the immune system starts to attack stomach cells, lowering your levels of a substance known as IF (Intrinsic Factor) which is produced in the lining of your stomach. IF helps the body to absorb vitamin B12 so without it, you can very easily become deficient, no matter how much of the vitamin you consume from your diet.

There is no known way to prevent pernicious anaemia, but it is treatable. Often sufferers are prescribed B12 supplements and advised to make certain changes to their diet.

How can you increase your intake of vitamin B12 naturally?

Can you increase your intake of vitamin B12 naturally? Yes, if you know where to find it in your diet. As I’ve previously mentioned, vegans and vegetarians in particular can struggle to get enough vitamin B12 in their diets since the vitamin is mostly found in animal derive products like meat, fish, eggs and milk.

However, silken tofu can provide an impressive amount of vitamin B12, offering 2.4mcg per 100g, so it’s a worthwhile dietary source. Many vegan foods are also fortified with B12, such as almond milk, coconut milk and cereals, which can count towards your daily intake.

If you are really struggling though, the best option may be to consider a natural B12 supplement. Our friends over at Jan de Vries offer a range of natural B12 supplements, but my favourite is definitely BetterYou’s Boost B12 Oral Spray. Rather than passing through your digestive system, this spray is absorbed directly through your cheek tissues which is great if you do suffer from digestive problems! It’s also 100% suitable for vegans and just 4 sprays provide an incredible 1200mcg of B12!

What happens if you get too much?

Can you get too much vitamin B12? Well, technically yes, because strictly speaking you can get too much of anything. The vitamin isn’t toxic and taking around 2mg (2000mcg) a day is unlikely to cause any harm according to NHS guidelines.5 However, remembering to take supplements in moderation is important so I definitely wouldn’t exceed 2mg a day – remember, the recommended daily amount is only 2.4mcg!


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