Superdrug pharmacist Niamh McMillan has shared key symptoms to look out for
Howard Lloyd Regional content editor, Neil Shaw Assistant Editor (Money and Lifestyle) and Neil Shaw
11:33, 21 Jan 2026
The expert warned that the ‘symptoms are easy to miss'(Image: Getty Images)
A pharmacist has urged people to watch for a range of symptoms associated with a vitamin deficiency. Superdrug pharmacy superintendent Niamh McMillan warned that the signs can be easily overlooked and may be linked to certain medications.
She said: “Vitamin B12 is essential for keeping our nerves and blood cells healthy, and a deficiency can sometimes develop slowly, meaning symptoms are easy to miss at first. Common signs to look out for include ongoing tiredness or weakness, shortness of breath, headaches, dizziness, pale skin, and a sore or red tongue. Some people may also experience pins and needles, numbness in the hands or feet, memory problems, difficulty concentrating, or low mood.
“B12 deficiency occurs when the body doesn’t get enough of the vitamin or can’t absorb it properly. This can be more common in people who follow a vegan or vegetarian diet, as B12 is mainly found in animal products. It can also affect older adults, people with digestive conditions such as coeliac disease or Crohn’s disease, and those taking certain medications, including long-term acid-reducing treatments like proton pump inhibitors or metformin.
“To help prevent B12 deficiency, it’s important to include good dietary sources where possible. Foods rich in vitamin B12 include meat, fish, eggs, milk, cheese and yoghurt. Fortified foods such as some breakfast cereals and plant-based milks can also help, particularly for those avoiding animal products. In some cases, supplements may be beneficial, especially if dietary intake is limited or absorption is an issue.”
Niamh further advised: ” If someone is experiencing symptoms or is at higher risk of deficiency, they should speak to a healthcare professional. A simple blood test can check B12 levels, and early treatment can help prevent longer-term complications. Superdrug Health Clinics offer a Vitamin B12 Injection Service at selected locations across the UK, following clinical assessment or evidence of deficiency.”, reports Bristol Live.
Certain types of medication can disrupt how your body absorbs or processes vitamin B12. This typically occurs because the drug alters the environment in your stomach or gut, making it more difficult for the vitamin to be released from food or transported into your bloodstream.
The most common medications associated with B12 deficiency include:
Proton Pump Inhibitors (PPIs): Examples include omeprazole, esomeprazole, and lansoprazole.H2 Blockers: Examples include famotidine and cimetidine.MetforminOral Contraceptives – some experts debate whether it leads to a “true” deficiency.Colchicine: A medication used for gout that can damage the lining of the intestine, affecting B12 absorption.Anticonvulsants: Certain drugs used for seizures, such as phenytoin or phenobarbital, can interfere with B vitamin metabolism.Nitrous Oxide: Also known as “laughing gas”, it can rapidly inactivate the B12 already in your body.Antibiotics: Long-term use of antibiotics like chloramphenicol or neomycin can disrupt gut bacteria that assist in B12 processing.
If you are taking any of these medications long-term:
Do not stop taking them without consulting your doctor.Watch for symptoms: Fatigue, “pins and needles” in hands or feet, brain fog, or a sore, red tongue.Get tested: A simple blood test can check your B12 levels. Many doctors now recommend periodic screening for patients on long-term metformin or PPIs.