GPs should offer patients a blood test for vitamin B12 deficiency if they have one symptom and at least one risk factor, NICE has said.
The advice forms part of the first-ever draft guideline on B12 deficiency diagnosis and management, published today and open to a six-week consultation.
It offers guidance on how to diagnose the condition in primary care, and which treatment option to use depending on the cause of the deficiency.
B12 deficiency can lead to a wide range of symptoms and complications, including mental health problems and neurological problems such as cognitive impairment, NICE said.
Its guideline aims to improve diagnosis and management, reduce complications and ‘improve quality of life for patients with suspected and confirmed deficiency’.
Vitamin B12 deficiency is more common in older people and is thought to affect around 5% of 65-74-year-olds and over 10% of over-75s. It can be caused by a diet lacking in B12; problems with absorption from the gastrointestinal tract; as well as recreational nitrous oxide use.
- If one sign or symptom and one or more risk factors are present, a blood test should be offered. Risk include age, previous surgery of the digestive system and autoimmune conditions.
- A methylmalonic acid (MMA) should be used to confirm diagnosis, if initial testing is inconclusive.
- Treatment should be considered if their test is indeterminate and vitamin B12 deficiency is suspected, with or without doing an MMA test.
- Recommended treatments include intramuscular injections of vitamin B12 or oral replacement for the treatment of deficiency, depending on the cause.
- In cases where diet is the cause, GPs should offer advice on changes to diet and advice on OTC supplements.
Untreated vitamin B12 deficiency can lead to health complications including anaemia and tiredness, eyesight problems such as blurred vision, mobility problems such as impaired balance, and delirium.
The consultation closes at 5pm on Tuesday 22 August.
Last year, the MHRA said GPs should consider periodic vitamin B12 testing of higher-risk patients who take metformin, even if they don’t display symptoms of deficiency
When to test for B12 deficiency
1.2.1 Offer an initial diagnostic test for vitamin B12 deficiency to people who have:
• at least 1 symptom or sign (see the section on symptoms and signs)
• 1 or more risk factors for the condition (see the section on risk factors).
1.2.2 Use clinical judgement when deciding whether to test people who have at least 1 symptom or sign but no risk factors (see the section on symptoms and signs).
1.2.3 Do not rule out a diagnosis of vitamin B12 deficiency based solely on the absence of anaemia or macrocytosis. See the recommendations on initial tests.