Tired? Forgetful? It could be down to a lack of vitamin B12
It’s a problem that’s easy to treat but too often patients are misdiagnosed and left to suffer for years
SAMANtHA NASH had seemingly endless supplies of energy. As well as working as a community midwife, the mother of two would run at least nine miles a week, walk her dog daily and enjoy weekend hiking in the Peak District with her husband, John.
these days Samantha, 42, often barely has the energy to make a cup of tea.
As well as suffering crippling fatigue, her legs can feel so leaden she can hardly lift them; her concentration can be poor and she’s had to quit the job she loved and no longer feels safe to drive.
Yet Samantha’s problems were not caused by some terrible disease but by an easily treatable yet frequently overlooked health problem: vitamin B12 deficiency.
Vitamin B12 plays an important role in health — for example, it helps brain and nervous system function, and is important for the formation of blood cells. It is also needed for the manufacture of myelin, the material that surrounds certain nerve cells.
A lack of vitamin B12 typically causes extreme fatigue, muscle weakness and problems with memory and concentration. It can also lead to temporary infertility in women, while a lack of it during pregnancy can result in foetal abnormalities.
the nutrient is found in red meat, fish and dairy products and most people can get enough from diet. However up to 18 per cent of the population are deficient in it, 80 per cent of these are women, according to anecdotal evidence from retired GP Dr Joseph Chandy, president of the B12 Deficiency Support Group.
Deficiency is linked to ageing and in the elderly, it may be linked to dementia, adds David Smith, a professor emeritus of pharmacology at Oxford University. ‘Once levels fall below 500 pg/ml (picograms per millilitre — the normal range being 500 to 1,000), the brain starts to deteriorate at twice the usual rate, making memory loss six times more likely.’
Yet if diagnosed early, a deficiency can be easily treated with injections of the vitamin that cost just 60p per dose. Under NICe guidelines, these jabs should be given on alternate days for two weeks. then typically a maintenance dose is given every three months for life.
However the jabs can be continued on alternate days if there are neurological symptoms — NICe says this should be until symptoms improve.
the problem is that treatment can be delayed because the symptoms of B12 deficiency are so diverse, clinicians may overlook the problem, or confuse it with other conditions, including depression and even multiple sclerosis, says Professor Smith.
Left untreated, a vitamin B12 deficiency can cause serious and sometimes permanent neurological damage.
Samantha experienced pins and needles and numbness in her right hand for several months before she finally went to see her GP in 2014 when one morning she had no feeling at all in her right hand for two hours.
‘It was absolutely terrifying. I thought it could be multiple sclerosis or something equally awful,’ she says.
Her GP initially said she had carpal tunnel syndrome, caused by compression of the nerves in the hand, but also decided to do some blood tests to rule out other causes such as thyroid problems.
It was only by chance that the laboratory added a check of her vitamin B12 levels to the list of tests. Her levels were extremely low.
Her GP immediately put her on a course of injections — six over a course of two weeks and then a further injection three months later.
‘I was astonished to be told I had a dietary deficiency,’ says Samantha. ‘Working in health, and being very keen on fitness, I’ve always had a good diet, so it didn’t make any sense.’
In fact diet is rarely a cause of a deficiency, explains Dr Premini Mahendra, a consultant haematologist at the Queen elizabeth Hospital in Birmingham.
that’s because the vitamin can be easily obtained from food sources — for instance 3oz (85)g of canned tuna provides around 2.4mcg. ‘Since it is found in red meat and dairy products, it tends to be vegetarians and vegans who are prone to dietary deficiency,’ she explains.
More common is for a deficiency to arise from an inability to absorb the vitamin correctly. Simply getting older increases this risk because as we age, the stomach shrinks and produces less of the acid needed for B12 to be absorbed.
It can also result from pernicious anaemia, a condition where the immune system attacks cells in the stomach that produce a protein called instrinsic factor — the body needs this to help it absorb B12.
Conditions such as Crohn’s disease — inflammation of the lining of the digestive system — can also mean the body doesn’t get enough vitamin B12.
early diagnosis and treatment is critical. Yet Professor Smith says diagnosis can be delayed as blood tests are not a foolproof way to detect a deficiency. He points out that under NHS guidelines B12 deficiency has to be identified by one of two possible blood tests — ‘both of which are unreliable,’ he says.
One of these tests looks for macrocytic (enlarged) blood cells; the other measures the total amount of B12 in the blood. ‘But you can be B12 deficient and sail through these tests.’
the definition of deficiency in the UK is a reading below 200 pg/ml — but Professor Smith says harm to the brain ‘can begin at anything below 500’.
He says GPs should not rely on one of these tests but should look for symptoms that suggest B12 deficiency — including pins and needles, and see if these improve with B12 treatment.
After finishing her course of injections in July 2015, Samantha’s symptoms improved initially but a month afterwards, she began to experience problems with her legs.
‘My left foot felt heavy when I was walking and I had to concentrate when going up stairs or a kerb,’ she says.
‘I was also extremely apathetic and became easily overwhelmed.’
Her GP was not convinced her new symptoms were due to low B12 and referred Samantha to a neurologist who diagnosed chronic fatigue and repeatedly asked Samantha if she was depressed. ‘I kept telling him I wasn’t — it was just so frustrating.
‘Meanwhile my family were getting more and more worried about me. I just knew it had to be my B12 again.’
By December 2015, still on threemonthly maintenance doses of B12 injections, Samantha’s mobility continued to decline and her concentration ‘was terrible’.
‘On the rare occasion I would go into a shop, I couldn’t remember what to buy.’
ReSeArCHING on the internet Samantha discovered that for someone with so many neurological sideeffects, having B12 injections every other day could help.
there is however no clinical data to support this approach, says Shankara Paneesha, a consultant haematologist at Spire Parkway Hospital in Solihull and Heart of england NHS Foundation trust.
‘Anecdotally, patients have told me how their neurological symptoms have improved after taking more than the recommended amounts of B12,’ he says.
‘that is their choice, but they have had to source this for themselves.’
Samantha’s GP agreed to prescribe alternate day injections, for six months, which brought some improvement but by May 2016, the doctor felt the treatment had been going on for too long.
She now sources her own vitamin B12 injections from an online pharmacy in Germany.
As well as the daily jabs she takes 5mg of folic acid as this helps absorption of vitamin B12.
this, she claims, has stopped her symptoms getting any worse.
Yet she is left with the neurological damage she believes is down to her initial undiagnosed deficiency.
‘I get tired and sometimes my speech gets a little confused.’ Her arms and legs also often feel drained of strength.
‘I firmly believe that if I’d received vitamin B12 on alternate days until my symptoms were much improved I would still be working in a job I love and enjoying the life I had.
‘My world has shrunk because of my deficiency.’