What Happens if You Lack Vitamin B6? Uncovering the Symptoms and Health Risks

October 30, 2025 •

3 min read

While severe vitamin B6 deficiency is rare in developed countries, suboptimal levels are more common in certain populations and can have significant health impacts. To understand what happens if you lack vitamin B6, it's important to recognize the diverse and often subtle symptoms that can arise from this crucial nutrient shortage.

Quick Summary

A deficiency in vitamin B6 can result in anemia, skin problems, and neurological issues like confusion and peripheral neuropathy. Various risk factors, including chronic illnesses, medications, and alcohol use, can cause low levels. Treatment typically involves dietary changes or supplementation to reverse symptoms.

Key Points

Neurological Problems: A deficiency can cause peripheral neuropathy (pins and needles), mood issues like depression and anxiety, and in severe cases, confusion and seizures.
Dermatological Issues: Skin conditions like seborrheic dermatitis, inflamed tongue (glossitis), and cracked lips (cheilosis) can signal low vitamin B6.
Anemia: A lack of vitamin B6 impairs hemoglobin production, leading to a form of anemia that causes fatigue and weakness.
Weakened Immune System: Insufficient B6 can reduce the body's ability to produce antibodies and immune cells, compromising immune function.
Underlying Causes: Risk factors include chronic illnesses like kidney disease, malabsorption disorders, autoimmune conditions, alcoholism, and certain medications, in addition to poor diet.
Treatment Options: Addressing the deficiency involves either increasing intake of B6-rich foods or, for more significant deficiencies, taking supplements under medical supervision.

The Diverse Roles of Vitamin B6

Vitamin B6, also known as pyridoxine, is a water-soluble vitamin essential for numerous bodily functions. It acts as a coenzyme in over 100 enzymatic reactions, primarily involved in the metabolism of proteins, fats, and carbohydrates. Beyond metabolism, it is crucial for synthesizing neurotransmitters like serotonin, dopamine, and GABA, impacting brain development and mood. Vitamin B6 also aids in the formation of hemoglobin, vital for oxygen transport in red blood cells, and supports immune function by helping produce antibodies and immune cells. A deficiency can thus affect multiple systems.

What Happens If You Lack Vitamin B6? Common Symptoms

A deficiency in vitamin B6 can lead to a range of symptoms, often non-specific and potentially mimicking other health issues, making diagnosis challenging without testing. Symptoms can impact the nervous system, skin, and overall energy levels.

Neurological and Mental Health Symptoms

Low vitamin B6 can significantly impact the nervous system and mental health due to its role in neurotransmitter production. Symptoms may include:

Peripheral Neuropathy: Characterized by tingling or numbness in the hands and feet. Severe cases can impair mobility.
Mood Changes: Deficiency can lead to depression, irritability, and anxiety. Confusion can occur in adults with severe deficiency.
Seizures: A rare but serious symptom, particularly in infants.

Dermatological Symptoms

Healthy skin relies on sufficient vitamin B6. Deficiency can cause:

Seborrheic Dermatitis: A scaly, itchy rash commonly found on the face, scalp, neck, and upper chest.
Oral Issues: Including a swollen tongue (glossitis) and cracks at the corners of the mouth (cheilosis).

Other Health Complications

A shortage of vitamin B6 can also lead to broader health problems.

Anemia: Specifically microcytic anemia, caused by impaired hemoglobin production, resulting in fatigue and weakness.
Weakened Immune System: Making individuals more prone to infections.

Causes and Risk Factors for Deficiency

While dietary deficiency is not common in many areas, several factors increase the risk of low vitamin B6 levels:

Poor Diet: Particularly in cases of food insecurity or highly restrictive diets.
Alcoholism: Impairs absorption and metabolism of B6.
Malabsorption Issues: Conditions like Celiac or Crohn's disease.
Kidney Disease: Especially in those undergoing dialysis.
Certain Medications: Including isoniazid and some anticonvulsants.
Autoimmune Conditions: Such as rheumatoid arthritis.
Pregnancy and Breastfeeding: Due to increased demand.

Comparison of Deficiency Causes


Factor	Dietary Insufficiency	Secondary Causes (Medical Conditions)
Prevalence	Less common, typically associated with very poor intake.	More common in at-risk populations.
Severity	Can be mild to moderate, depending on dietary habits over time.	Can range from marginal to severe, and often associated with chronic disease.
Primary Cause	Lack of B6-rich foods in the diet, potentially due to processing.	Underlying health issues impacting absorption or metabolism.
At-Risk Groups	Vegans/vegetarians (due to lower bioavailability in plants), older adults, malnourished individuals.	Patients with kidney disease, autoimmune diseases, alcohol dependence, pregnant women.
Treatment Focus	Increasing consumption of B6-rich foods.	Addressing the underlying condition, dietary changes, and potentially higher-dose supplementation.

Diagnosing and Treating Vitamin B6 Deficiency

Diagnosis often involves a clinical assessment and blood tests to measure pyridoxal 5'-phosphate (PLP) levels. Treatment varies based on the cause and severity. Mild deficiencies from diet can be corrected by increasing B6-rich food intake. More severe cases or those due to medical conditions may require supplementation. Medical consultation is crucial before supplementing, as high doses can be harmful.

Excellent Food Sources of Vitamin B6

Key sources include:

Fish and poultry (tuna, salmon, chicken breast)
Organ meats (beef liver)
Starchy vegetables (potatoes, winter squash)
Legumes (chickpeas, lentils)
Fortified grains
Fruits (bananas, papayas, oranges)
Nuts and seeds

Conclusion

Although severe vitamin B6 deficiency is uncommon, insufficient levels can lead to various health problems, including skin conditions, anemia, and significant neurological issues. Recognizing symptoms and understanding risk factors are key to addressing a potential deficiency. Incorporating foods rich in vitamin B6 is beneficial, but consulting a healthcare professional for diagnosis and treatment is essential for anyone suspecting a deficiency to ensure a safe and effective approach to restoring optimal B6 levels.

A helpful resource for further information on vitamin B6 is the National Institutes of Health Office of Dietary Supplements.

Frequently Asked Questions

The earliest signs can often be non-specific and include fatigue, irritability, and skin rashes. As the deficiency progresses, you may notice more specific symptoms like tingling or numbness in your hands and feet.

Yes, vitamin B6 is critical for producing neurotransmitters that regulate mood. A deficiency can lead to mood disorders such as depression, anxiety, and increased irritability.

Several conditions increase the risk, including kidney disease, malabsorption disorders like Crohn's and Celiac disease, and autoimmune disorders like rheumatoid arthritis.

Yes, some medications are known to interfere with B6 metabolism. These include the tuberculosis drug isoniazid, certain anticonvulsants, and some other prescription drugs.

A doctor can diagnose a deficiency based on a clinical evaluation of your symptoms, medical history, and risk factors. A blood test to measure the levels of pyridoxal 5'-phosphate (PLP) is the most common diagnostic tool.

Excellent food sources include fish (like tuna and salmon), poultry, beef liver, potatoes, chickpeas, and bananas. Many breakfast cereals are also fortified with vitamin B6.

Yes, while difficult to achieve from diet alone, excessive intake of vitamin B6 from supplements can lead to nerve damage (sensory neuropathy), often with a loss of control of body movements. Therefore, supplementation should always be guided by a doctor.