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5 Signs You Have a Vitamin B12 Deficiency

This essential vitamin plays a major role in keeping our bodies running, so it makes sense that a deficiency can stop us in our tracks. Learn the signs that your B12 levels are interfering with your health.

You may have heard vitamin B12 called “the energy vitamin.” That’s because your body needs it to convert food into fuel. “Vitamin B12 is one of our essential vitamins,” says Dr. Katrina Gooden, a family medicine physician with Galen East Internal Medicine and Pediatrics. “In addition to providing energy, we use it for brain and nerve function, red blood cell production, and DNA synthesis.”

Vitamin B12 occurs naturally in animal products like fish, meat, eggs, milk, and cheese. Other foods, including plant-based milk and certain breakfast cereals, are commonly fortified with synthetic B12. You can even purchase the supplement form of B12 at your local pharmacy.

B12 is water soluble, which means your body only absorbs the small amount it needs, and the rest is excreted in your urine. Most people can easily consume the daily recommended amount of B12 through their diet; however, if you face absorption issues or fall into one of the other groups prone to shortage, you may be deficient.

pills and vitamins illustration in Chattanooga

As many as 20% of people are borderline B12 deficient. Susceptible populations include strict vegetarians or vegans, because plant foods don’t naturally contain B12; adults over 50, since stomach acid, a key part of B12 absorption, decreases as you age; individuals with gastrointestinal disorders, such as celiac disease (gluten intolerance) and Crohn’s disease (a chronic inflammatory bowel disease); and those who have undergone weight loss surgery, which eliminates the part of the stomach that breaks down B12. Certain acid-reducing and diabetes medications can put you at risk as well.

If any of these categories describe you, there’s no need to fret! B12 deficiency, should you be diagnosed, is easily treated with B12 shots or pills. The hardest part is recognizing the symptoms. Here are five common signs that may suggest your B12 levels have dipped too low.

Your memory isn't what it used to be.

Constantly forgetting the name of your favorite restaurant or misplacing your keys more than normal? A foggy brain can be an indicator of a vitamin B12 deficiency. In fact, extreme B12 deficiency often mimics the symptoms of dementia like memory loss, disorientation, and a struggle to think or reason. That’s because low B12 can hinder your brain chemistry, causing an imbalance in your neurotransmitters. If left untreated, these issues can become permanent.

In older adults, it can be especially difficult to distinguish the difference between a B12 deficiency and dementia since they’re at risk for both and the two conditions frequently overlap.

Fortunately, most people with B12 deficiency visit the doctor before dementia-level symptoms begin; however, if you or a loved one are experiencing any sort of cognitive decline, it’s important to get tested for B12 deficiency. “It’s one of the first tests a doctor will order if memory issues are present,” explains Dr. Gooden.

Effective vitamin B12 replacement will correct blood counts in around two months and correct or improve neurological signs and symptoms within six months. Permanent damage to nerves is more likely if diagnosis and treatment are delayed by six months."

You have tingling in your hands and feet.

An ongoing vitamin B12 deficiency can lead to nerve damage, which can sometimes cause a pins-and-needles feeling in your hands or feet. “Vitamin B12 is needed to help neurons function,” explains Dr. Sarah Baker, an internist with CHI Memorial Chattanooga Internal Medicine Group. 

“When B12 levels are too low, neurons can’t effectively function, which leads to symptoms like numbness or tingling in the hands and feet.” This numbness or tingling is called paresthesia, and it can become permanent if left untreated.

Nerve damage caused by an insufficient amount of the vitamin can also affect your balance and ability to walk. This too can become permanent if not treated, so it’s important to mention to your doctor if the issue arises.

Additional neurological issues that could develop include myelopathy, which is a disease of the spinal cord; neuropathy, or disease of the nerves; increased clumsiness; and weakness. Of course, many of these can also be attributed to old age or a number of other causes, which makes it all the more important to get tested by your doctor.

You're always tired.

Having trouble staying awake even though you had a full night’s sleep? Weakness, fatigue, and lethargy are common symptoms of B12 deficiency. When your body doesn’t have enough B12, it can’t produce the number of red blood cells needed to properly transport oxygen to your organs, which leaves you feeling tired. This is a form of anemia. Shortness of breath may be present as well.

A form of anemia specific to B12 deficiency is called pernicious anemia. “Pernicious anemia is the most common severe cause of B12 deficiency,” explains Dr. Baker. It is an autoimmune disorder caused by an inability to absorb vitamin B12 due to lack of intrinsic factor (a protein made in your stomach for B12 absorption). It was originally called pernicious – meaning dangerous or detrimental – because most cases were fatal.

But since B12 treatments were discovered, it’s actually quite easy to treat. “Certain populations, like those with absorption issues, will require shots since they can’t absorb B12 through their stomachs,” says Dr. Gooden. “If levels are low, but not due to absorption issues, shots and pills have been proven to be equivalent.”

You constantly feel stressed or anxious.

Unfortunately, your physical health isn’t the only thing that can be affected by B12 deficiency. It can also wreak havoc on your mental health, and in extreme circumstances lead to depression and anxiety. This is because B12 helps to produce serotonin and dopamine, your brain’s mood-regulating neurotransmitter chemicals. Dopamine controls your brain’s reward and pleasure centers, while serotonin helps to regulate sleep and appetite and is considered a mood stabilizer.

When your B12 is low, production of those neurotransmitters is inhibited, your sleep patterns may become irregular, and your emotions start to wander. It’s not a long descent into depression or anxiety when your brain chemistry is off. If you don’t have any obvious stressors affecting your mood, ask your doctor to check your B12 levels.

Your tongue is smooth, and your heart beats irregularly.

Severe B12 deficiency can cause blood flow issues that result in pale skin, bruising, mouth sores, and glossitis, which is a swollen and inflamed tongue. Glossitis causes you to lose papillae, the tiny bumps on your tongue that contain taste buds, and leaves your tongue shiny and smooth, extremely red, and sore.

Other symptoms that can result from poor blood flow are a rapid heartbeat or heart palpitations. If you’ve developed pernicious anemia, your heart must work harder to pump blood to oxygenize your body’s tissues. The added stress on your heart from these blood flow issues can cause rapid, strong, or irregular heartbeats, an enlarged heart, or even heart failure.

If any of these signs are hitting too close to home for you or a loved one, schedule a visit with your doctor. A quick blood test could be all you need to put you back on track to a healthy vitamin B12 level.

Picture of Dr. Katrina Gooden

Dr. Katrina Gooden

Family Medicine Physician, Galen East Internal Medicine and Pediatrics

Picture of Dr. Sarah Baker

Dr. Sarah Baker

Internist, CHI Memorial Chattanooga Internal Medicine Group

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