Vitamin B12 Injections – Who Are They For and How Do They Work?
What is Vitamin B12 and why is it important?
Vitamin B12 (cobalamin) is an essential water-soluble vitamin that plays a key role in:
Red blood cell formation
Normal neurological function
DNA synthesis
Energy metabolism
Low vitamin B12 levels can lead to symptoms such as fatigue, brain fog, pins and needles, low mood, and in more severe cases, anaemia or nerve damage.
What causes low Vitamin B12 levels?
Vitamin B12 deficiency can occur for a number of reasons, including:
Malabsorption conditions (e.g. pernicious anaemia, coeliac disease, Crohn’s disease)
Gastrointestinal surgery, such as gastric bypass
Long-term use of certain medicines, including metformin or proton pump inhibitors (PPIs)
Dietary deficiency, particularly in people following a vegan or very restrictive diet
Because B12 absorption is complex and relies on intrinsic factor in the stomach, oral supplements are not always effective for everyone.
What are Vitamin B12 injections?
Vitamin B12 injections contain hydroxocobalamin, a prescription-only form of vitamin B12 administered by intramuscular injection.
They are commonly used when:
A confirmed B12 deficiency is present
Absorption from the gut is impaired
Rapid correction of low levels is clinically appropriate
In the UK, hydroxocobalamin injections are Prescription Only Medicines (POM) and must be prescribed following an appropriate clinical assessment.
How do B12 injections work?
When injected into muscle, vitamin B12 is absorbed directly into the bloodstream, bypassing the digestive system.
This makes injections particularly effective for people who cannot absorb B12 adequately through food or oral supplements.
Treatment schedules vary depending on the underlying cause and severity of deficiency and should always be guided by a clinician.
Can everyone have B12 injections?
Not necessarily. Vitamin B12 injections are not suitable for everyone, and they are not a general wellness treatment.
A proper assessment is essential to determine:
Whether symptoms are likely to be related to B12 deficiency
Whether blood tests are required
Whether injectable treatment is clinically appropriate
Unnecessary B12 injections should be avoided.
How can a pharmacy help?
At Pharmacy Clinic Edinburgh, vitamin B12 injections are offered only following a pharmacist-led consultation and, where appropriate, prescribing.
This ensures treatment is safe, clinically justified, and compliant with UK medicines regulations.
