During Covid, my sister’s vitamin B12 injections for pernicious anaemia were changed to tablets, which her body was unable to absorb. A blood test showed she now has severe iron deficiency anaemia, too. Has her lack of B12 contributed to this new diagnosis?

Linda Pearsall, Burton on Trent.

Pernicious anaemia means you cannot properly absorb vitamin B12. As well as being key to making red blood cells, B12 is important for healthy nerve cells, and a shortfall can lead to symptoms including pale skin, muscle weakness or bleeding gums. 

As many as 20 per cent of over-60s and 6 per cent of under-60s have pernicious anaemia.

It’s actually an autoimmune condition, where our antibodies attack cells lining the stomach which create a protein called intrinsic factor. 

The only treatment is a regular injection of B12: this gets the vitamin straight into the bloodstream (file image) 

Taking it orally is pointless, as it can’t be absorbed due to the lack of intrinsic factor, says Dr Martin Scurr

This substance combines with vitamin B12 to aid its absorption in the small intestine, so the damage caused to the cells leads to a lack of the vitamin.

(Quite why this condition becomes more common with age isn’t clear, but it could be that after a lifetime’s worth of exposure to infections, the body is more likely to make antibodies similar to those that damage the cells.)

The only treatment is a regular injection of B12: this gets the vitamin straight into the bloodstream. Taking it orally is pointless, as it can’t be absorbed due to the lack of intrinsic factor.

Normally, a patient with pernicious anaemia should receive a B12 injection every three months. It can also be given monthly.

But during the pandemic many patients had their injections stopped and were put on ineffective pills instead — a bad decision, made without a clear understanding of the condition. Your sister should not have had her injections stopped. To do so is tantamount to stopping the insulin injections required by someone with type 1 diabetes and is reprehensible.

It may be that the iron deficiency anaemia she’s since developed is linked to her pernicious anaemia, as you suggest.

Iron deficiency anaemia can be caused by chronic blood loss in the intestine.

Patients with pernicious anaemia sometimes develop gastric polyps — abnormal growths on the lining of the stomach — which can lead to microscopic but persistent blood loss. These growths are a consequence of the inflammation caused by our antibodies attacking the stomach lining.

It’s essential to get a referral to a gastroenterologist for an endoscopy and a biopsy of the stomach lining.

My 59-year-old daughter is an anxious person who catastrophises everything. She’s done her best to control her panic, but it would be a great help if she knew it wasn’t harmful, and a time scale for asking for medical help.

Name and address supplied.

I’m so sorry to hear about your daughter’s anxiety. Catastrophising is a tendency to see the worst-case scenario in any anxiety-provoking situation, causing an overwhelming sense of fear, along with racing thoughts and profound pessimism.

You say in your longer letter that when your daughter developed migraines, for example, she decided it meant she had a brain tumour. This is a classic type of reaction.

Catastrophising is a symptom of anxiety disorders. Anxiety has its uses — it evolved in mankind as a way to improve our survival. But when amplified and out of control it creates ill health, and it’s not unusual for it to lead to headaches or a racing heart, for example (largely due to an excess of stress hormones).

The answer is not medication but rather psychological help — specifically, cognitive behavioural therapy, a talking therapy that can alter someone’s understanding of everyday events and their reaction to them.

I would urge your daughter to see a GP for a referral — I’m afraid there is a wait for this treatment on the NHS, but another option is to pay for it privately.

I sincerely hope your daughter is able to get the help she needs.

• Write to Dr Scurr at Good Health, Daily Mail, 9 Derry Street, London, W8 5HY or email: drmartin@dailymail.co.uk. Dr Scurr cannot enter into personal correspondence. Replies should be taken in a general context. Consult your own GP with any health worries. 

In my view: We need honesty on food products 

Do you know what constitutes a processed or ultra-processed food (UPF)? There has been a lot of talk about UPFs recently, but I suspect quite a few people are confused about what makes it different from the former.

A processed food is one that has been altered in some way (which may include something as basic as being put into a can or a jar).

The evidence that UPFs are a major factor in the escalating obesity crisis is mounting and yet the options to change this are limited (file image) 

In contrast, by definition (and I refer to the work of the Brazilian researchers who first identified them), UPFs are mostly or entirely made with ingredients that sound as if they belong in a chemistry lab rather than on our plates. A multitude of processes are used to make these long-lasting, highly profitable, highly palatable products.

The evidence that UPFs are a major factor in the escalating obesity crisis is mounting and yet the options to change this are limited. What’s more, we have little idea about what it is in UPFs — chemicals and additives, or something else — that’s actually causing the harm.

The time has come for food producers and governments to commit more time and energy to exploring the potential pitfalls of UPFs. I acknowledge that food production is a business and people want to eat well for less, but we must prioritise the health of the nation.