Exhaustion, bad mood and shortness of breath are symptoms of vitamin B12 deficiency

Motivated by the health benefits of a plant-based diet, Carly Minsky, then in her mid-20s, saw cutting out meat and fish as a natural and desirable step.

At first, she “felt great,” she says, as she enthusiastically committed herself to her new regimen. However, after a year, it was a completely different story.

“I started feeling really tired,” Carly recalls. ‘It wasn’t just fatigue, it was extreme fatigue.’ She also gained weight.

“I walked like this for six years, I didn’t know what was wrong, and by 2020 I could barely walk because I was so exhausted,” says the 33-year-old journalist from London.

Finally, worried that it might be a problem with the thyroid gland (which produces hormones to regulate metabolism), she visited her general practitioner in 2021, who sent her for blood tests.

Within days, Carly was called back to the doctor’s office and told that her vitamin B12 levels had dropped so dramatically that she would need emergency vitamin injections every other day for the next six weeks, and then high-potency vitamin B12 pills every day for life. Cause? Her diet.

Vitamin B12 is mainly found in animal and dairy products — meat, fish, eggs, milk and cheese, for example — and is vital for a number of key body functions, including brain health and red blood cell production.

A deficiency can lead to health problems including anemia (low iron levels in the blood), fatigue, palpitations, shortness of breath, nerve problems and mental health problems.

People over 60, who are more likely to have nutritional deficiencies, and people with pernicious anemia, an autoimmune condition that means the body can’t absorb B12 properly, are at risk. So are vegans.

Earlier this year, the National Institute for Health and Care Excellence (NICE) reported that 6 per cent of the under-60 population is B12 deficient, rising to 11 per cent among vegans.

Although Carly still ate cheese and eggs, and drank milk, her intake during those vegetarian years was insufficient and her vitamin B12 levels dropped.

‘My GP said I was dangerously low on the scale and needed urgent B12 shots,’ she says. ‘It was a huge shock. I had no idea it would get so bad.

‘It took two months of injections before I started to feel better, and apparently I still take vitamin B12 tablets every day.’

Most people get enough B12 through their diet — the recommended intake is 1.5 micrograms per day (an average diet of chicken, fish, beef and eggs will give you enough).

‘But some people – including those on restrictive diets that do not consume animal products or who eat a poor diet high in processed foods – do not get enough vitamin B12,’ says Sue Pavord, consultant haematologist at Oxford University Hospitals and vice-president of the British Society of Haematology .

She says B12 deficiency is a seriously neglected area of ​​public health, affecting 10 percent of people over the age of 60.

‘The human body is unable to produce B12 and therefore needs it from food,’ she explains. ‘Early symptoms of deficiency can be vague, such as fatigue or symptoms of anemia — palpitations, shortness of breath and exhaustion.

‘But as the deficiency progresses, neurological symptoms may develop — such as tingling in the fingers and toes or loss of balance.’

This is because B12 is vital for maintaining and forming the protective sheaths that cover nerves, ensuring that messages are transmitted quickly and efficiently, explains Dr Moez Dungarwalla, consultant haematologist at Milton Keynes University Hospital.

“A fatty substance called myelin is necessary for the formation of these sheaths, and vitamin B12 plays a significant role in the synthesis and maintenance of myelin,” he explains. ‘Neurological problems caused by B12 deficiency are partly due to damage to the myelin sheath.’

In extreme cases, vitamin B12 deficiency is associated with macular degeneration (which can lead to vision loss), heart disease, cognitive impairment, dementia, stroke, and psychosis.

However, vague — or lack of — early symptoms can mean some people are unaware they suffer from a potentially serious deficiency, as former counselor Stephen Wright has discovered.

The 70-year-old from Dorset only found out he had a B12 deficiency at a GP appointment two years ago. Routine blood tests showed he was seriously deficient in vitamins and would need injections every six weeks for life to prevent the development of neurological disorders.

Doctors believe that his deficiency is due to his age and his unhealthy diet.

Some pre-existing conditions can also lead to a deficiency — the most common being pernicious anemia, says David Smith, emeritus professor of pharmacology at the University of Oxford.

“Penic anemia affects one in 1,000, and up to one in 500 in the over-60s,” he says. ‘It is an autoimmune disease with family ties. It is not known what triggers it, but it prevents the absorption of vitamin B12 in the intestines.’

Other diseases that impair B12 absorption include decreased gastric acid secretion (again, common with age) and Crohn’s disease and celiac disease.

Some medicines interfere with the absorption of vitamin B12, including metformin (used to treat diabetes) and proton pump inhibitors such as omeprazole (for acid reflux).

The good news is that in most patients the symptoms can be reversed.

As Professor Smith explains: ‘Most people will be able to correct their low vitamin B12 status by taking tablets, and a good starting dose is 1 microgram a day. Many patients with pernicious anemia require injections.’

But people often don’t find out they have a deficiency until the damage is done.

‘If someone is not treated, there can be irreversible changes in the neurological system,’ says Dr. Pavord. ‘These include difficulty walking, due to weakness; loss of balance and sensation; and impaired vision.’

Along with B12 injections, Stephen has adopted a low-carb diet, lost three pounds and feels much more energetic. “I had no idea how important vitamin B12 was until I went through it,” he says.

Carly’s symptoms disappeared within two months of starting vitamin B12 treatment. ‘It was like my energy was switched on again,’ she says.