Vitamin B12 is an essential nutrient that helps your body produce healthy red blood cells, supports nerve function, and plays a key role in making DNA. Because the body cannot produce vitamin B12 on its own, it must be obtained through food or supplements. When levels become too low, a wide range of symptoms can develop—some of them surprisingly unusual.
Many of these symptoms can also have other causes, so they don’t necessarily mean you have a vitamin B12 deficiency. If you experience persistent symptoms, it’s important to consult a healthcare professional, who can confirm a deficiency with appropriate testing.
1. Tingling or “Pins and Needles” in Your Hands and Feet
One of the earliest signs of vitamin B12 deficiency is numbness or a tingling sensation in the fingers, toes, hands, or feet. B12 is vital for maintaining the protective covering around nerves (myelin). Without enough B12, nerves may not function properly, leading to unusual sensations.
2. Constant Fatigue That Doesn’t Improve with Rest
Feeling exhausted even after a full night’s sleep may be a sign of low vitamin B12. A deficiency can reduce the body’s ability to produce healthy red blood cells, limiting oxygen delivery to tissues and leaving you feeling weak and drained.
3. Problems with Balance and Walking
If you’re stumbling more often or feel unusually unsteady, low vitamin B12 may be affecting your nervous system. In severe or prolonged deficiency, nerve damage can impair coordination and balance.
4. A Smooth, Sore, or Bright Red Tongue
Some people with vitamin B12 deficiency develop glossitis, an inflamed tongue that appears smooth, swollen, or bright red. It may also be painful and make eating or speaking uncomfortable.
5. Memory Problems or Difficulty Concentrating
Low vitamin B12 can affect brain function, leading to forgetfulness, confusion, difficulty concentrating, or “brain fog.” These symptoms can occur for many reasons, but B12 deficiency is one possible cause.
6. Pale or Slightly Yellow Skin
Because vitamin B12 is needed to produce healthy red blood cells, a deficiency can contribute to anemia. This may cause the skin to appear unusually pale. In some cases, the skin or the whites of the eyes may develop a slight yellow tint due to increased breakdown of fragile red blood cells.
7. Mood Changes
Some people with low vitamin B12 report symptoms such as irritability, low mood, or anxiety. While B12 deficiency can contribute to these symptoms, mental health conditions have many potential causes, so a proper medical evaluation is important.
8. Shortness of Breath or Heart Palpitations
If vitamin B12 deficiency leads to anemia, the heart and lungs may work harder to deliver oxygen throughout the body. This can result in shortness of breath during normal activities or a sensation of a rapid or pounding heartbeat.
Who Is Most at Risk?
Certain people are more likely to develop vitamin B12 deficiency, including:
- Adults over age 60.
- Vegans and strict vegetarians who don’t consume fortified foods or supplements.
- People with digestive disorders such as Crohn’s disease or celiac disease.
- Individuals who have had stomach or intestinal surgery.
- People taking certain medications, such as long-term metformin or acid-reducing medications.
- Those with pernicious anemia, an autoimmune condition that affects B12 absorption.
Foods Rich in Vitamin B12
Good dietary sources of vitamin B12 include:
- Beef and liver
- Fish such as salmon, tuna, and trout
- Shellfish like clams
- Eggs
- Milk, yogurt, and cheese
- Poultry
- Fortified breakfast cereals
- Fortified plant-based milks and nutritional yeast
People who don’t consume animal products may need fortified foods or supplements to meet their needs.
When to See a Healthcare Professional
Talk to your healthcare provider if you experience ongoing fatigue, numbness, balance problems, or other symptoms that could be related to vitamin B12 deficiency. A simple blood test can often help determine whether your vitamin B12 levels are low. Early diagnosis and treatment are important because prolonged deficiency can sometimes lead to nerve damage that may not be fully reversible.
Final Thoughts
Vitamin B12 deficiency can affect many parts of the body, from your nerves and blood cells to your brain and energy levels. While these eight signs may raise suspicion, they are not specific to vitamin B12 deficiency and can have many other causes. If you notice persistent or worsening symptoms, seek medical advice rather than self-diagnosing. With proper testing and treatment, many people recover well and prevent long-term complications.