Vitamin B12 is one of those essential nutrients your body needs to function properly. According to the National Institutes of Health, It’s mainly responsible for producing red blood cells, supporting your nervous system, and helping create DNA. But here’s the thing—since your body can’t make it on its own, you’ve got to get it from your diet or supplements.

If you’re not getting enough, it could lead to some serious health issues. Here are 11 signs that your body may be running low on vitamin B12 and what that might mean for your overall health.

1. You Feel Constantly Tired, Even After Resting

One of the most common signs of a B12 deficiency is extreme fatigue. This occurs because vitamin B12 helps your body produce red blood cells. These cells carry oxygen to your tissues, and when there’s a shortage, your body works harder to get oxygen where it needs to go. The result? You feel drained all the time, even after a good night’s sleep.

2. You Experience Numbness or Tingling in Your Hands and Feet

Nerve health is closely linked to vitamin B12, so when levels drop, you may start feeling strange sensations like numbness or tingling, especially in your hands and feet. According to research, this happens because B12 helps create myelin, the protective coating around your nerves. Without enough myelin, nerve signals get interrupted, causing those weird feelings in your extremities.

3. You Have Pale or Jaundiced Skin

Noticing that your skin is looking paler than usual or even slightly yellowish? That could be a red flag for B12 deficiency. The Cleveland Clinic explains that when your body doesn’t have enough B12, it struggles to produce healthy red blood cells, leading to a condition called megaloblastic anemia. This condition makes your skin appear pale, and the breakdown of red blood cells can give your skin a jaundiced tint.

4. You Struggle With Mood Swings or Depression

Vitamin B12 plays a critical role in brain function and mood regulation. Several studies have found a link between low levels of B12 and mental health issues like depression, anxiety, and mood swings. In fact, the Indian Journal of Psychological Medicine notes that B12 helps synthesize neurotransmitters like serotonin, which influences your mood. When those levels dip, it can lead to emotional changes.

5. Your Memory is Getting Worse

If you’ve noticed that you’re becoming more forgetful or struggling with memory, vitamin B12 deficiency could be the culprit. Research suggests that low levels of B12 can lead to cognitive decline and even increase the risk of dementia in older adults. This is because B12 is essential for maintaining brain health, so a deficiency could seriously affect your cognitive abilities.

6. You’re Often Short of Breath or Dizzy

If you find yourself out of breath after even light physical activity or feeling dizzy frequently, it may be time to consider your vitamin B12 intake. According to StatPearls, low B12 can lead to anemia, which reduces the number of oxygen-carrying red blood cells in your body. This means your organs aren’t getting enough oxygen, causing breathlessness and dizziness.

7. Your Muscles Feel Weak and You Lack Strength

B12 deficiency can cause muscle weakness, especially in your legs and arms. When your muscles don’t get enough oxygen, they simply don’t perform as well. For some people, this can make everyday tasks, like climbing stairs or carrying groceries, feel much harder than they should.

8. You Have a Sore, Swollen Tongue

Your tongue can tell you a lot about your health. A sore, red, or swollen tongue could be a sign that your B12 levels are too low. This condition, called glossitis, can also make your tongue feel smooth and shiny. B12 helps maintain the health of your tongue’s mucous membranes, so when you’re deficient, inflammation can occur, leading to pain and swelling.

9. You Experience Digestive Issues Like Diarrhea or Constipation

Digestive problems such as diarrhea, constipation, or bloating may be linked to low vitamin B12 levels. This happens because B12 helps support the health of your gut. When you’re deficient, the lining of your gastrointestinal tract may become inflamed, which can mess with digestion and cause symptoms like nausea, diarrhea, or constipation.

10. Your Vision Has Become Blurry

If your vision has started to blur, it could be related to a lack of vitamin B12. Per The Journal of Optometric Education, optic nerve damage can occur in severe B12 deficiency cases, leading to vision disturbances. When the optic nerve is affected, it interrupts the signals that travel from your eyes to your brain, causing your vision to become blurry or double.

11. You Have Difficulty Walking or Balance Problems

Some people with long-term B12 deficiency may experience difficulty walking or maintaining balance. This symptom is related to nerve damage caused by the deficiency. Multiple studies have shown that prolonged low levels of B12 can damage the part of the brain responsible for movement, thus leading to coordination problems and a higher risk of falls, especially in older adults.

How to Boost Your Vitamin B12 Levels

If these signs sound familiar, you may want to think about boosting your vitamin B12 intake. But how? Most people get enough from animal-based foods like meat, fish, eggs, and dairy products. For vegetarians and vegans, though, getting enough can be challenging, since B12 is mostly found in animal products. If that’s the case, fortified foods like cereals or plant-based milk might be your best bet, or you could consider taking a supplement.

In any case, if you suspect a B12 deficiency, it’s best to talk with your doctor. They can check your B12 levels with a simple blood test and recommend the appropriate treatment, whether that’s dietary changes, oral supplements, or even B12 injections in more severe cases.