Millions of people taking common medications such as omeprazole or metformin are being urged to watch for signs of vitamin B12 deficiency, which can cause serious health issues if left untreated. Superdrug Pharmacy Superintendent Niamh McMillan warned that symptoms can develop slowly and are often overlooked.
Key Symptoms of B12 Deficiency
According to McMillan, “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.”
Who Is at Risk?
B12 deficiency occurs when the body does not get enough of the vitamin or cannot absorb it properly. It is more common in vegans and vegetarians, older adults, people with digestive conditions like coeliac disease or Crohn’s disease, and those taking certain long-term medications. McMillan highlighted that proton pump inhibitors (PPIs) such as omeprazole, esomeprazole, and lansoprazole, as well as metformin, are frequently linked to impaired B12 absorption.
Medications That Interfere with B12
Several types of drugs can affect B12 levels. These include PPIs, H2 blockers like famotidine and cimetidine, metformin, oral contraceptives (though some debate exists), colchicine for gout, anticonvulsants like phenytoin or phenobarbital, nitrous oxide (laughing gas), and long-term antibiotics such as chloramphenicol or neomycin. These medications alter stomach acidity or gut function, reducing B12 absorption.
Prevention and Treatment
“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,” McMillan advised.
She added: “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 UK locations following clinical assessment or evidence of deficiency.
What to Do If You Take These Medications
Patients on long-term PPIs or metformin should not stop taking them without consulting their doctor. Instead, they should watch for symptoms like fatigue, pins and needles, brain fog, or a sore red tongue, and request a blood test. Many doctors now recommend periodic B12 screening for those on long-term metformin or PPIs.
