Vitamin B12 deficiency can develop slowly, and some symptoms are easy to mistake for normal aging, stress, or other health issues. Left untreated, a significant deficiency can affect the nervous system and blood cells, so it’s worth recognizing the possible signs.
Common signs of vitamin B12 deficiency that may be overlooked
- Unusual tiredness or weakness
- Feeling exhausted, low in energy, or less able to do normal activities.
- Numbness or tingling
- “Pins and needles” sensations in the hands, feet, or legs can occur when nerves are affected.
- Balance problems
- Feeling unsteady, clumsy, or having more difficulty walking.
- Memory or concentration changes
- Trouble focusing, mental “fog,” or forgetfulness may occur.
- Mood changes
- Irritability, low mood, or symptoms that resemble depression can sometimes be associated with deficiency.
- Pale skin or unusual shortness of breath
- B12 deficiency can lead to a type of anemia that reduces the blood’s ability to carry oxygen.
- Sore or swollen tongue
- Some people develop a smooth, painful tongue or mouth discomfort.
- Vision changes (less common)
- Nerve-related effects can rarely affect vision.
People at higher risk include:
- Older adults with reduced stomach acid
- People with absorption problems (such as certain intestinal conditions)
- Those taking certain medications, including long-term metformin or acid-reducing medicines
- People who eat little or no animal products without B12 supplementation
When to get checked
If you have persistent fatigue, numbness, balance issues, or memory changes, a healthcare professional can check B12 levels and related tests. Treatment is usually straightforward when a deficiency is confirmed.
Do not start high-dose supplements indefinitely without knowing your levels, because symptoms can have many causes and need the right diagnosis.
