Anaemia (vitamin B12 or folate deficiency)

Last Updated: July 3, 2026

Key Points

Caused by a lack of vitamin B12 or folate (B9)
Leads to abnormally large, poorly functioning red blood cells
Symptoms include extreme tiredness and nerve problems
Often treated with vitamin injections or tablets

Overview

Vitamin B12 or folate deficiency anaemia happens when your body doesn't have enough of these essential vitamins. This shortage prevents your body from making healthy red blood cells, which are crucial for carrying oxygen throughout your body. Instead, it produces large, ineffective red blood cells. These vitamins are vital for many body functions, including keeping your nervous system healthy. A deficiency can lead to a range of issues, from extreme tiredness to problems with your memory and nerve function. It's important to get diagnosed and treated quickly, as some problems caused by this condition can become permanent if left untreated. Treatment usually involves replacing the missing vitamins through injections or tablets.

Signs and Symptoms

Extreme tiredness
Lack of energy
Pins and needles sensation
Sore, red tongue
Mouth ulcers
Muscle weakness
Vision problems
Depression or anxiety
Memory and judgment issues

Things That Increase the Risk

Pernicious anaemia (immune system attacks stomach cells)
Vegan diet without B12 supplements
Restrictive or poor diet
Certain medications (e.g., anticonvulsants, PPIs)
Being aged 65 or older

Diagnosis

Review of symptoms
Blood test to check vitamin levels
Blood test to check red blood cell size and count

Treatment & Management

Vitamin B12 injections (initial treatment)
Regular B12 tablets or ongoing injections
Folic acid tablets for folate deficiency (usually 4 months)
Dietary changes to include B12-rich foods
Dietary changes to include folate-rich foods

Prevention

Ensure adequate vitamin B12 intake through diet
Include meat, fish, eggs, dairy, fortified foods (for B12)
Include green vegetables like broccoli, peas (for folate)
Vegans should take B12 supplements or fortified foods
Regular check-ups if on certain medications

Available Treatments

Explore our range of treatment options for Anaemia (vitamin B12 or folate deficiency):