How Do You Know If Your B12 Is Low?
Low B12 levels can show up in many ways, especially in how you feel day-to-day. People commonly report tiredness, weakness, changes in mood, or trouble with memory and focus. Digestive discomfort can also show up when levels are low.
Vitamin B12 (cobalamin) is an essential water-soluble vitamin that supports red blood cell formation, DNA synthesis, and the healthy functioning of the nervous system.
If B12 levels drop too low, your body may not produce enough healthy red blood cells, which can affect oxygen transport and contribute to feeling unwell. Many animal-based foods contain B12, such as fish, poultry, eggs, and dairy. Some breads and plant-based milks are also fortified to help support adequate intake.
Certain groups are more likely to have low B12 levels, including older adults, people who follow a vegan diet, individuals taking metformin, and those who’ve had digestive surgeries affecting B12 absorption.
Sometimes B12 deficiency can also affect folate levels, which may temporarily mask symptoms — another reason it’s important to identify the underlying cause with a healthcare provider.
Below, you’ll find some commonly reported signs associated with low B12 levels.
1. Jaundiced or Pale Skin
People with low B12 may appear pale or slightly yellow-tinged. This can happen when the body doesn’t produce enough healthy red blood cells, or when cells break down more quickly, increasing bilirubin levels.
If you notice changes in skin tone or the whites of your eyes, it’s a good idea to speak with a doctor to check your B12 status.
2. Feeling Tired or Weak
Fatigue and weakness are among the most frequently reported symptoms associated with low B12. When your body doesn’t have adequate B12 to support red blood cell formation, oxygen transport may be affected — which can leave you feeling worn out or sluggish.
3. Pins and Needles Sensations
B12 helps support the production of myelin, the protective coating around your nerves. Low levels can contribute to nerve-related sensations like tingling or “pins and needles,” also known as paresthesia.
While this feeling can have many causes, persistent tingling should always be assessed by a healthcare provider.
4. Trouble With Balance or Coordination
Some individuals with long-term low B12 levels report changes in mobility, coordination, or balance. These issues tend to appear more often in older adults but can happen at any age if B12 levels are severely low.
5. Mouth Ulcers or Glossitis
An inflamed, swollen, or smooth tongue (glossitis) may be associated with low B12 levels. Some people also notice mouth ulcers, burning sensations, or changes in how foods taste.
6. Dizziness or Shortness of Breath
Shortness of breath or lightheadedness — especially during physical activity — can occur when red blood cells aren’t able to carry oxygen efficiently. These symptoms can have many causes, so evaluation by a doctor is important.
7. Blurred or Disturbed Vision
Low B12 may affect the optic nerve, which can lead to visual disturbances. This is sometimes referred to as optic neuropathy. Some reports suggest this may improve when B12 levels are restored, but this must be evaluated and monitored by a healthcare provider.
8. Mood Changes
Some research links low B12 levels to mood alterations. B12 plays a role in neurological function, and imbalances can affect how you feel mentally or emotionally. However, mood changes can arise for many reasons, and B12 supplementation supports mood only when low B12 is present.
9. Elevated Body Temperature
This is a less common and not well-understood symptom reported in some individuals with low B12. If you experience unexplained changes in body temperature, follow up with a healthcare provider.
Conclusion
Many factors can contribute to B12 deficiency, and symptoms vary widely from person to person. If you think your B12 levels might be low, the most accurate way to confirm is through a blood test ordered by your doctor.
If you’re looking to support healthy levels, sublingual B12 supplements can be a convenient option — but always check with your healthcare provider to determine what’s right for your needs.
This information is for educational purposes only and is not medical advice. The products and strategies mentioned are not intended to diagnose, treat, cure, or prevent any condition. Please consult your doctor or qualified healthcare professional before starting any new supplement or making changes to your wellness routine.