Vitamin B12 deficiency is common enough that it can be overlooked, especially because its symptoms can develop gradually and resemble those of other conditions. However, these symptoms are not specific to B12 deficiency, so a medical evaluation and blood tests are needed to confirm the cause.
Common signs and symptoms include:
- Fatigue and weakness – Often due to anemia caused by low B12.
- Numbness or tingling in the hands or feet – B12 is important for healthy nerves.
- Difficulty walking or poor balance – Nerve damage can affect coordination.
- Memory problems or difficulty concentrating – Sometimes described as “brain fog.”
- Mood changes – Such as depression or irritability.
- A sore, smooth, or red tongue and sometimes mouth ulcers.
- Pale or slightly yellowish skin due to anemia.
- Shortness of breath or a rapid heartbeat during physical activity, if anemia is significant.
People at higher risk include:
- Older adults
- Vegans or strict vegetarians who do not consume B12-fortified foods or supplements
- People with conditions that reduce B12 absorption (such as certain stomach or intestinal disorders)
- People taking some medications, including long-term metformin or acid-reducing medications
A healthcare professional can diagnose B12 deficiency with blood tests and determine the underlying cause. Treatment may involve oral B12 supplements or B12 injections, depending on the severity and the reason for the deficiency.
If you have new numbness, trouble walking, significant weakness, or confusion, it’s important to seek medical evaluation promptly, as nerve damage from prolonged B12 deficiency can become permanent if not treated early.
