These Symptoms Indicate That You Need More Vitamin B12

The average adult needs 2.4 grams of vitamin B12 every day. According to Harvard Health, B12 (or cobalamin) creates red blood cells, protects the nerves, and keeps your brain functioning. When someone lacks vitamin B12, they experience some strange symptoms. For instance, their tongue might get bigger, they lose more hair, and they even struggle to walk. If you feel these symptoms, you might need more vitamin B12.

Weakness And Tiredness

According to the Government of HealthLink British Columbia, people with vitamin B12 deficiency are more likely to develop anemia. With too few vitamins, the body cannot create enough red blood cells. This results in people feeling weak and tired.

A woman sleeps outside with her book over her eyes.
Tony Tran/Unsplash
Tony Tran/Unsplash

In 2012, a study in PLoS ONE determined that vitamin B12 deficiency results in intense fatigue. Stroke patients with low vitamin B12 were more likely to feel weak, which also raised their risk of clinical depression. If you continually feel tired, double-check your diet to ensure that you’re getting enough vitamins.

Hair Loss And Greying

In 2019, research in Dermatology Therapy determined that vitamin B12 is one of the four nutrients that could lead to premature hair loss (the others being iron, folate, and vitamin D). Vitamin B12 can even make peoples’ hair turn grey.

A woman holds out a brush with a lot of hair on it.

Hair follicles rely on vitamin B12 to remain healthy. When they do not receive enough nutrients, the follicles become discolored and fall out. In 2016, a report in the International Journal of Trichology found that even women younger than 25 can develop grey hairs because of a vitamin B12 deficiency.

Pins And Needles

“Pins and needles” is the feeling of tingling, usually in your hands and feet. Doctors have a more official term for this: paraesthesia. A lack of vitamin B12 can trigger pins and needles continuously for weeks to months.

A doctor examines an elderly woman's hands.
BSIP/UIG Via Getty Images
BSIP/UIG Via Getty Images

According to the Foundation for Peripheral Neuropathy, vitamin B12 has a positive effect on our nerves. When we do not get enough B12, the myelin sheath that surrounding nerves become damaged. The nerves then stop functioning properly, and they can feel tingly or numb. If you experience pins and needles often, talk to your doctor.

Not Being Able To Walk As Well

Sometimes, when people have difficulty walking, they might suffer from a vitamin B12 deficiency. Researchers from the University of California, San Francisco, noted that a lack of B12 made walking and balance more difficult for Parkinson’s patients. This is because the vitamin upkeeps the nervous system.

A man sits down and rubs his aching ankle.
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BSIP/Universal Images Group via Getty Images

Study author Dr. Chadwick Christine says that vitamin B12 produces myelin, which protects nerve cells and keeps your muscles safe. With less protection, your nervous system might have a harder time moving. People with little vitamin B12 tend to fall and stumble more often.

A Specific Type Of Headache

A lack of vitamin B12 might cause headaches–but a certain kind of headache. The Thyroid Patient Advocacy says that most vitamin B12-related headaches are migraines that include blurriness in the corner of your vision and facial pain, mainly under the eyes.

A woman touches her head in pain.
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BSIP/Universal Images Group via Getty Images

The National Headache Association says that B vitamins tend to treat headaches, while a lack of B vitamins makes them worse. Even if your headaches do not match the above description perfectly, they still might be a sign of a vitamin B12 deficiency. Talk to your doctor if you’re unsure.

Pale Or Jaundiced Skin

Believe it or not, red blood cells influence the color of your skin, and a lack of vitamin B12 means fewer blood cells. A spokesperson for the Academy of Nutrition and Dietetics, Sonya Angelone, explains that blood cells “aren’t doing the job of carrying oxygen and oxygenating the blood, so that can lead to paleness.”

A man with a pale face looks up at the camera.

When red blood cells deteriorate, they create a substance called bilirubin. According to research in Postgraduate Medicine, an excess of bilirubin can cause jaundice, or yellow skin. These changes in skin tone might indicate a lack of vitamin B12.

An Inflamed Tongue

Stanford Medicine says that a vitamin D deficiency can make your tongue larger, sore, and beef-red in color. This condition is called glossitis, and it can alter the way you eat, taste, and speak. Your tongue might also feel more smooth.

A person sticks her tongue out.

In 2009, a study from the American Academy of Dermatology found that many people with vitamin B12 deficiency had glossitis. Even if they did not have anemia, they still had the symptom. Other causes include bacterial infections, viruses, allergic reactions, or trauma to the mouth.

Vision Loss

Vitamin B12 is essential for brain function. In 2017, optometrist researchers found that vision loss is a common symptom of B12 deficiency. Specifically, patients tend to experience painless vision blurriness or loss of color sight.

A doctor covers a patient's eye during a vision test.
In Pictures Ltd./Corbis via Getty Images
In Pictures Ltd./Corbis via Getty Images

With no vitamins feeding your optic nerves, the cells become damaged and worsen your eyesight. Fortunately, vision loss does not have to be permanent. According to a 2005 study in the European Journal of Internal Medicine, patients can get their eyesight back with vitamin B12 supplementation. Talk to a doctor to learn if you think you have a vitamin B12 deficiency.

An Enlarged, Harmed Liver

In 2015, researchers found a link between vitamin B12 deficiency and non-alcoholic fatty liver disease. A lack of B12 could worsen liver disease, and vice-versa says the International Journal of Advanced Research. This is because a lack of vitamin B12 can enlarge your liver.

A diagram shows the front and back of the human liver.
Encyclopaedia Britannica/UIG Via Getty Images
Encyclopaedia Britannica/UIG Via Getty Images

According to the YAM Journal of Medical Sciences, vitamin B12 is primarily stored in the liver. Without it, the liver cannot function as well, and people have a higher risk of cirrhosis and other liver diseases. Unfortunately, this symptom is much harder to pinpoint.

An Irregular Heartbeat

Vitamin B12 levels directly influence a person’s heart rate. The University of Rochester Medical Center explains that too little B12 can increase a person’s heartbeat and cause palpitations. When the body has few red blood cells, the heart has to pump more blood to make up for it.

A heartbeat appears on a machine.
Fairfax Media via Getty Images via Getty Images
Fairfax Media via Getty Images via Getty Images

Because of the heartbeat change, people with low B12 tend to have shortness of breath and dizziness as well. On the other hand, too much vitamin B12 can slow the heart rate as the heart tries to limit how many red blood cells it gets.

Breathlessness And Dizziness

In 2019, a study in the journal Acta Clinica Croatica examined the symptoms of people with vitamin B12 deficiency. They found that most patients of any age experienced breathlessness and dizziness. This is because, when you do not have enough B12, your body has less oxygen.

A room appears fuzzy as if seen through the eyes of a dizzy person.
Radvilas Seputis/Unsplash
Radvilas Seputis/Unsplash

According to the University of Rochester Medical Center, red blood cells carry oxygen to the lungs and other body tissues. A lack of red blood cells could hinder breathing, making people feel dizzy. If you experience dizziness along with these other symptoms, check your B12 levels.


People with insufficient B12 levels are more likely to develop depression. In 2005, researchers analyzed several studies about depression and vitamin B12. They discovered that depressed patients are far more likely to have a vitamin B12 deficiency. On the flip-side, taking B12 supplements tended to improve depression symptoms.

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Jonathan Rados/Unsplash
Jonathan Rados/Unsplash

Scientists believe that vitamin B12 stabilizes serotonin levels in the brain. A lack of serotonin is one potential cause of depression. That said, supplementing vitamin B12 will not “cure” depression. But some evidence suggests that it could influence symptoms.

Ringing Ears

Everyone’s ears ring once in a while, but people who experience it frequently have tinnitus. A lack of vitamin B12 is directly related to tinnitus. According to the Summit Hearing Aid Center, people with a vitamin B12 deficiency are more likely to hear ringing, buzzing, or humming in one or both ears.

A woman with tinnitus clutches her ears in pain.
BSIP/Universal Images Group via Getty Images
BSIP/Universal Images Group via Getty Images

Without vitamin B12, the nerves in the ears do not receive as many nutrients. These nerves might get damaged over time, worsening your hearing. In 2016, research in Noise Health found that 42.5% of tinnitus patients have a vitamin B12 deficiency.


The National Heart, Lung and Blood Institute claims that constipation is a common sign of vitamin B12 deficiency. This vitamin has a notable effect on the digestive tract. Specifically, it aids nerves in the intestines, and without that function, your bowel movements might suffer.

A woman clutches her abdomen in pain.
BSIP/Universal Images Group via Getty Images
BSIP/Universal Images Group via Getty Images

The Journal of Nutrition, Health & Aging describes vitamin B12 deficiency “as a digestive disorder.” Many elderly people need laxatives to combat this symptom of B12 deficiency. But remember that there are several causes of constipation other than a lack of vitamin B12.

…Along With Diarrhea And Nausea

While a lack of vitamin B12 can cause constipation, it can also trigger diarrhea. These seemingly-opposite symptoms have the same source. Medical News Today says this is because not enough oxygen reaches the gut, which makes the body feel sick.

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Francisco Gonzalez/Unsplash
Francisco Gonzalez/Unsplash

This anemia can manifest in intense nausea and diarrhea, according to the Journal of Applied Hematology. Even infants can experience “persistent diarrhea” if they do not receive enough vitamin B12. That said, diarrhea has many causes, so talk to a professional if you think that it is vitamin B12.

Memory Loss

In 2019, research in The BMJ claimed that a lack of vitamin B12 could cause “reversible dementia.” Participants had low B12 levels and few red blood cells. Because the blood cells did not send as many nutrients to the brain, the participants suffered from memory loss.

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Vitamin B12 deficiency might accelerate memory loss in seniors. A study in the British Journal of Nutrition discovered that one in eight seniors does not get enough vitamin B12. Lack of vitamins is not a cause of dementia, but it can noticeably impact your memory.

Loss Of Appetite

Although almost all of our vitamin B12 comes from food, people who lack this vitamin might not be hungry. In 2015, a study in BMJ Case Reports noticed that many vegetarians and vegans with a vitamin B12 deficiency tend to experience a loss of appetite.

A woman refuses to eat a meal that is on her tray.

There are many reasons for this symptom. One is general gastrointestinal issues that people who lack vitamin B12 tend to have. Others say that this is a side effect of anemia. Either way, people who do not feel hungry often might need to consume more vitamin B12.

Weight Loss (Contrary To Popular Belief)

Some websites claim that weight gain is a common symptom of vitamin B12 deficiency. However, there is little evidence of this. According to 2010 research in the journal Nutrients, people who lack vitamin B12 tend to experience weight loss because of their lack of appetite.

A woman with slippers on steps on a scale to weigh herself.
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That said, the weight loss might be minor. In 2005, researchers studied weight gain in participants who fixed their vitamin B12 deficiencies with supplements. On average, they gained between 2.5 and 17 pounds. That means that even minor weight loss could be a sign of vitamin B12 loss.

An Itchy Skin Rash

People with a lack of vitamin B12 might get a wide variety of skin rashes. According to Tri-City Medical Center, B12 encourages cells to reproduce. When skin cells do not reproduce, it can cause dryness, discoloration, inflammation, and itchiness.

A woman scratches her arm.

The College of Family Physicians of Canada relates vitamin B12 deficiency to numerous skin problems. These include hyperpigmentation, vitiligo (white patches), angular stomatitis (swollen red patches near the lips), and lesions. Some patients might even break out in hives. During the late stages of vitamin B12 deficiency, a variety of skin conditions might appear.

Becoming Sick More Easily

Vitamin B12 fortifies the immune system, and without it, you might get sick more easily. Registered dietitian and nutritionist Stephanie Middleberg told Health that vitamin B12 helps the body produce white blood cells. With fewer white blood cells, the immune system becomes weaker.

A girl with a cold sits up in her bed and blows her nose.
marka/Universal Images Group via Getty Images
marka/Universal Images Group via Getty Images

In Clinical & Experimental Immunology, a study confirmed that vitamin B12 is crucial for keeping people healthy. Getting enough B12 might prevent you from feeling sick. At the same time, some autoimmune conditions, such as Graves’ disease, can result in a vitamin B12 deficiency.