New vitamin B12 guidance for UK doctors

By Nikki Hancocks

- Last updated on GMT

Getty | jarun011
Getty | jarun011

Related tags Vitamin b12 guidance B vitamins Vitamin b12 deficiency

General Practitioners (GPs) in the UK are advised to offer patients a blood test for vitamin B12 deficiency if they see one symptom and one risk factor, in new guidance currently under consultation.

Newly published advice from NICE (The National Institute for Health and Care Excellence) forms part of the first-ever draft guideline on B12 deficiency diagnosis and management, which is open to a six-week consultation​ (closing on 22 August).

The guidance aims to raise awareness of the condition, leading to better diagnosis, treatment and ongoing care. It also aims to improve diagnosis and management, reduce complications and ‘improve quality of life for patients with suspected and confirmed deficiency’.

The report comes hot on the heels of a presentation on vitamin B deficiency during pregnancy at the Nutrition Society conference​, in which an expert argued there is a need for better detection and reduction of deficiencies in order to support cognitive health outcomes in offspring.

Previously there has been no UK guidelines regarding the treatment of vitamin B12 deficiency during pregnancy, and no specific dosing recommendations.

The new NICE report provides specific advice for pregnant and breastfeeding patients: "Oral vitamin B12 replacement prescribed during pregnancy or breastfeeding should be given at a dosage of at least 1,000 micrograms a day. This is because the body can need more vitamin B12 in pregnancy and during breastfeeding, so setting a minimum dose will ensure that enough vitamin is being absorbed. This should help ensure the health of anyone who is pregnant or breastfeeding, and of their child."

The report notes that, in the general population, B12 deficiency can lead to a wide range of symptoms and complications, including mental health problems and neurological problems such as cognitive impairment.

It outlines circumstances in which vitamin B12 deficiency is more more common, such as in older people. In fact, it is thought to affect around 5% of 65-74-year-olds and over 10% of over-75s. It can also be caused by a diet lacking in B12, problems with absorption from the gastrointestinal tract, as well as recreational nitrous oxide use.

The draft guidelines recommend​ that if one sign or symptom and one or more risk factors are present, a blood test should be offered. Risks 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, and treatment should also be considered if their test is indeterminate.

Recommended treatments include intramuscular injections of vitamin B12 or oral replacement, depending on the cause.

The guidance states that injections could be the best option for people in whom treatment needs to work quickly because they are at risk of rapid deterioration that could significantly affect their quality of life.

The new guidelines also recommend that injections could also be a better option than supplementation if there are concerns about adherence to oral replacement.

In cases where diet is the cause, GPs should offer advice on changes to diet and advice on OTC supplements.

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

The guidance warns not to rule out a diagnosis of vitamin B12 deficiency based solely on the absence of anaemia or macrocytosis. See the recommendations on initial tests.


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