Vitamin B12 deficiency is common. It can lead to various health issues, affecting everything from energy levels to brain function.

Vitamin B12, or cobalamin, is an essential nutrient in meat, fish, and dairy products. It is crucial for red blood cell production and a healthy nervous system.

When B12 levels are low, the body’s ability to perform vital functions becomes compromised, leading to symptoms that can sometimes be subtle and nonspecific.

This article explores the unusual symptoms of B12 deficiency, when people may need to contact a doctor, treatment, and prevention.

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The recognized symptoms of vitamin B12 deficiency include fatigue, weakness, and megaloblastic anemia.

Doctors recognize megaloblastic anemia by the presence of unusually large, structurally atypical, immature red blood cells (megaloblasts) in the bone marrow. A vitamin B12 deficiency disrupts DNA synthesis, leading to red blood cells that cannot carry enough oxygen throughout the body.

However, a B12 deficiency can also manifest with less typical symptoms, including:

  • Neurological changes: Individuals may experience tingling or numbness in the hands and feet, muscle weakness, and difficulty with balance and coordination.
  • Cognitive impairment: People may notice changes in cognitive functions, including memory loss and difficulty concentrating. Some may experience mood swings or signs of depression.
  • Vision problems: Unexplained vision issues such as blurred vision or disturbances in the visual field can occur, although this is rare.
  • Dental issues: Oral problems, including tongue discomfort, mouth ulcers, and a burning sensation in the mouth, may develop.
  • Infertility and reproductive health issues: People may experience fertility problems and irregular menstrual cycles.
  • Impaired sense of taste and smell: Some individuals might notice a reduced ability to taste and smell.

Doctors may find these symptoms perplexing, leading to misdiagnosis. Therefore, it is crucial to recognize them as potential indicators of B12 deficiency for timely and effective treatment.

What is B12 deficiency?

Vitamin B12 deficiency is a lack of vitamin B12, an essential nutrient necessary for various critical bodily functions.

B12 deficiency results when the body does not receive enough B12 from the diet or cannot absorb it properly. Without treatment, this deficiency can lead to a range of symptoms, from mild fatigue and tingling in the extremities to severe neurological damage and memory loss.

Vitamin B12 deficiency is more common in certain groups, including:

Learn more about B12.

It is best for individuals to talk with a healthcare professional if they experience symptoms that may suggest vitamin B12 deficiency. Early detection and treatment are crucial to prevent potentially severe complications associated with the condition.

Key signs that warrant a medical consultation include:

The benefits of B12 apply to various aspects of health, including:

  • Neurological function: Vitamin B12 is crucial for maintaining a healthy nervous system. It aids in forming the protective covering of nerves, known as the myelin sheath, which ensures the proper and efficient transmission of nerve impulses.
  • Red blood cell formation: One of vitamin B12’s primary roles is producing healthy red blood cells capable of carrying proper amounts of oxygen.
  • Energy production: B12 is necessary to metabolize fats and carbohydrates, converting them into energy.
  • Heart health: Vitamin B12, in combination with folate, helps lower homocysteine levels in the blood. Elevated homocysteine levels increase the risk of heart attacks and strokes.
  • Bone health: The body needs adequate levels of vitamin B12 for good bone health. Low levels are associated with a higher risk of osteoporosis.
  • DNA synthesis: It plays a significant role in DNA production, which is crucial for all cells in the body.
  • Mood and brain health: B12 synthesizes and metabolizes serotonin, a chemical responsible for regulating mood. Adequate levels of B12 help maintain brain health and reduce the risk of mood disorders and other conditions affecting the brain.
  • Supports pregnancy: Vitamin B12 is crucial during pregnancy to properly develop the nervous system of the fetus. Adequate levels of B12 reduce the risk of congenital disabilities, such as neural tube defects.

There are several potential causes of B12 deficiency, including:

  • Dietary insufficiency: People who follow a strict vegan or vegetarian diet may have an insufficient vitamin B12 intake, but this is rare.
  • Lack of intrinsic factor: The stomach produces this protein, which helps the body absorb vitamin B12. Individuals with pernicious anemia lack this protein, and older adults produce lower levels.
  • Lifestyle habits: Excessive alcohol consumption impedes B12 absorption. Guidelines define this as more than two alcoholic drinks per day for males and more than one per day for females.
  • Medications: Long-term use of certain medications, including some heartburn medicines and the diabetes drug metformin, can reduce vitamin B12 absorption.
  • Autoimmune conditions: Celiac disease, type 1 diabetes, thyroid disease, chronic pancreatic disease, and certain inherited conditions can affect B12 absorption.
  • Digestive issues: Ulcerative colitis, Crohn’s disease, and Helicobacter pylori infections can make it more challenging for the body to absorb B12.
  • Surgical procedures: Operations on the stomach or intestines, such as weight loss surgery or gastrectomy, can significantly decrease the body’s ability to absorb vitamin B12.

Diagnosing B12 deficiency typically involves a series of blood tests that assess various parameters, including:

  • Hemoglobin levels: Normal levels for males are 13 grams per deciliter (g/dL) or higher. For females, normal levels are 12 g/dL or higher. Lower levels may indicate anemia.
  • Vitamin B12 levels: Normal levels are 400 picograms per milliliter (pg/mL) or higher. Levels of 200 pg/mL or lower may indicate a deficiency. However, it is important to note that some individuals may still exhibit deficiency symptoms even with standard B12 levels.
  • Methylmalonic acid test (MMA): High levels of MMA can indicate B12 deficiency.

Treatment for B12 deficiency depends on the underlying cause and can include:

  • B12 supplements: These can be in the form of pills or injections.
  • Dietary changes: People can incorporate more B12-rich foods into their diet.
  • Management of underlying conditions: Addressing any health issues that impair B12 absorption may help.

With appropriate treatment, the outlook for those with B12 deficiency is generally excellent. Proper supplementation and dietary modifications can reverse most symptoms.

Preventing B12 deficiency involves:

  • Eating a balanced diet: It is crucial to consume B12-rich foods such as meat, dairy, and fortified cereals as part of a balanced diet.
  • Taking dietary supplements: Doctors may suggest taking B12 supplements, especially if a person is at a higher risk of deficiency due to lifestyle factors, age, or absorption impairments.
  • Regular screening: Older adults, individuals with gastrointestinal disorders, vegans, vegetarians, and those on long-term medications that affect B12 absorption should undergo regular screenings to monitor their B12 levels.

Vitamin B12 deficiency is a manageable condition that can manifest through common and unusual symptoms. Less common symptoms include neurological and cognitive changes, vision problems, and dental issues.

Understanding the importance of B12, recognizing the signs of deficiency, and obtaining timely medical care are crucial steps in maintaining optimal health and preventing the long-term consequences of this deficiency.