“I have been tortured by a weird dizziness, unbalance and loss of appetite for about a month. Brain fog and tendency to sleep/weakness for much longer.

“My neurologist suggested a series of tests (MRI scans, blood tests, inner ear etc) which all came back clean except B12 levels.”

The patient was prescribed a course of B12 supplements – one of the main forms of treatment. This improved her condition for about a week and then her symptoms came roaring back.

“My anxiety has increased due to my persisting symptoms and mostly because everyone is telling me that everything is in my head and my anxiety causes the dizziness,” they lamented.

“I know that everybody with B12 has a range of symptoms and retreat times, however is it normal to still feel bad after three weeks of supplements?”

Sadly, many patients are asking the same question. B12 deficiency can be fiendishly difficult to diagnose and treat.

This owes in part to the role that B12 plays in the body: the nutrient helps keep your body’s blood and nerve cells healthy and helps make DNA, the genetic material in all of your cells.

It naturally follows that B12 deficiency causes the body to malfunction in diverse and surprising ways. And the symptoms non-specific, which means a diagnosis is often delayed.

The treatment for vitamin B12 deficiency depends on what’s causing the condition. Most people can be easily treated with injections or tablets to replace the missing vitamins.

There are growing reports that some B12 sufferers are having their injections stopped and are been put on tablets, which have actually reversed some of the progress they have made.

If your vitamin B12 deficiency is not caused by a lack of vitamin B12 in your diet, you’ll usually need to have an injection of hydroxocobalamin every two to three months for the rest of your life, says the NHS.