Six signs of a vitamin B12 deficiency – expert advises when to take a supplement

With people needing “50 micrograms a day” of vitamin B12, if a person is deficient in the nutrient, symptoms can appear.

“Extreme tiredness, lack of energy, pins and needles, muscle weakness, depression and cognitive problems such as impaired memory, understanding and judgement can all be a sign of vitamin B12 deficiency,” said Dr Butler.

So where does vitamin B12 come from?

“B12 is produced by bacteria found in the soil,” revealed Dr Butler. “Traditionally, we would have got it from eating unwashed food.”

Dr Butler added: “But food is now so sanitised we need to get it from fortified foods or supplements.

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“Meat and dairy do contain it, but only because farmed animals are given a supplement for the same reason.”

Dr Butler stated: “You are better off cutting out the middleman and taking your own.”

The health advocate for the Vegetarian and Vegan Foundation reckons B12 is “more easily absorbed from supplements than from animal foods”.

She added: “This is important as absorption declines with age and everyone over 50, regardless of diet, which is why people should consider a supplement.”

Vitamin B12 helps the body maintain healthy nerve cells and helps in the production of DNA.

Dr Butler noted: “It also works closely with folic acid, to make red blood cells, to help iron work better in the body and to produce a compound involved in immune function and mood.”

A fan of plant-based food sources of vitamin B12, people wanting to top up their vitamin B12 levels are recommended to eat:

• Yeast extract (Marmite)
• B12-fortified yeast flakes, plant-based milk, vegan yoghurts and desserts.

“Make sure the ones you buy are fortified with B12, but remember to take a supplement too to ensure a reliable intake,” said Dr Butler.

There are consequences of having sustained low vitamin B12 levels, such as raised levels of the amino acid homocysteine in the blood.

Raised levels of homocysteine in the blood has been linked to heart disease, said Dr Butler.

“If you are concerned, B12 levels can be checked by a doctor and any deficiency can be treated with supplements or a course of injections,” she concluded.

Dr Justine Butler is the head of research at Viva!.