What Does a B6 Deficiency Look Like? Signs, Symptoms & Causes

December 29, 2025 •

2 min read

While severe vitamin B6 deficiency is relatively uncommon in the general population, a marginal deficiency can affect an estimated 24% of non-supplement users in the United States, according to data from the 2003–2004 NHANES analysis. Signs of inadequacy can be subtle but impact everything from skin health to mood regulation.

Quick Summary

A B6 deficiency can manifest through a range of symptoms, including skin problems like seborrheic dermatitis, neurological issues such as peripheral neuropathy and mood changes, as well as anemia and a weakened immune system. Underlying medical conditions, certain medications, and poor diet can all contribute to low B6 levels.

Key Points

Skin Problems: Look for a red, greasy, and scaly rash known as seborrheic dermatitis, and cracked lips or oral sores, which are common signs of B6 deficiency.
Neurological Issues: Peripheral neuropathy, causing numbness and tingling in the extremities, is a significant symptom resulting from B6's role in nerve health.
Mood and Mental Health: B6 deficiency can contribute to irritability, depression, anxiety, and confusion due to its involvement in neurotransmitter synthesis.
Anemia and Fatigue: A specific type of anemia called microcytic anemia, characterized by small red blood cells, can lead to persistent fatigue and weakness.
Weakened Immunity: A compromised immune system, making one more susceptible to infections, can be a symptom of low B6 levels.
Risk Factors: Individuals with alcohol dependence, kidney disease, autoimmune disorders, and those on certain medications are at a higher risk of developing a deficiency.
Diagnosis is Key: Blood tests measuring pyridoxal 5'-phosphate (PLP) are used for definitive diagnosis, as symptoms overlap with other conditions.

Recognising the Red Flags of B6 Deficiency

Vitamin B6, or pyridoxine, plays a critical role in numerous bodily functions, including metabolism, nerve function, and red blood cell production. When levels of this essential nutrient drop, the body begins to send signals, which can often be mistaken for other ailments. Recognizing these key indicators is the first step toward correcting the issue.

Skin and Oral Manifestations

Visible signs of a B6 deficiency can appear on the skin and in the mouth. Seborrheic dermatitis is a common presentation, characterized by an itchy, red rash, often on the scalp, face, and chest. Oral symptoms may include scaling and cracking at the corners of the lips (cheilosis), inflammation of the tongue (glossitis), and painful mouth ulcers (stomatitis).

Neurological and Psychological Symptoms

Vitamin B6 is essential for neurotransmitter synthesis, impacting nerve function and mood. Deficiency can cause peripheral neuropathy, leading to numbness or tingling in the hands and feet. Mood changes such as irritability, depression, and anxiety are also common. Cognitive impairment and confusion, particularly in older adults, can occur, and in rare, severe cases, seizures may develop.

Hematological and Immune System Effects

B6 is crucial for producing hemoglobin, affecting red blood cell production. A deficiency can result in microcytic anemia, causing fatigue and weakness due to small, pale red blood cells. Inadequate B6 can also weaken the immune system, increasing susceptibility to infections.

Risk Factors and Underlying Causes

While dietary deficiency is uncommon, risk factors include kidney issues, autoimmune diseases, alcohol dependence, and certain medications. Age and malnutrition can also contribute.

Comparing B6 Deficiency Symptoms to Other Conditions

Diagnosing B6 deficiency involves considering symptoms and medical history. The table below compares B6 deficiency symptoms with those of other conditions:


Symptom	B6 Deficiency	B12 Deficiency	Iron Deficiency Anemia
Skin Rash	Seborrheic dermatitis (red, oily, flaky)	Not typical, but can cause hyperpigmentation	Pallor (pale skin)
Oral Symptoms	Glossitis, cheilosis, stomatitis	Glossitis, mouth ulcers	Glossitis, smooth tongue, angular cheilitis
Neuropathy	Pins and needles, numbness, ataxia	Pins and needles, numbness, balance problems	Can occur, but less common; restless legs syndrome
Mood Changes	Irritability, depression, anxiety	Depression, irritability, memory loss	Irritability, depression
Anemia Type	Microcytic anemia	Macrocytic (megaloblastic) anemia	Microcytic anemia
Immune Function	Weakened immune response	Weakened immune response	Compromised immunity, recurrent infections

Diagnosis and Management

Diagnosis typically involves blood tests to measure PLP levels. Treatment usually includes addressing the deficiency with supplementation as guided by a healthcare professional and managing any underlying causes. A balanced diet rich in B6 can help prevent deficiency.

Conclusion

Understanding the varied signs of a B6 deficiency, from skin issues and oral sores to neurological and psychological symptoms, is key for early detection. While rare from diet alone, certain conditions and medications increase risk. Prompt diagnosis and treatment with a healthcare professional can effectively manage the deficiency. For further information, consult resources like the National Institutes of Health.

Frequently Asked Questions

Early signs can be subtle but often include fatigue, irritability, and skin problems like a red, scaly rash (seborrheic dermatitis) or cracked lips (cheilosis).

Yes, a B6 deficiency can lead to peripheral neuropathy, which is nerve damage that causes tingling, numbness, or a 'pins-and-needles' sensation in the hands and feet.

Mood changes can include irritability, anxiety, and depression. This is because vitamin B6 is vital for producing neurotransmitters that regulate mood, like serotonin and GABA.

Treatment usually involves addressing the deficiency with supplementation as guided by a healthcare professional and managing any underlying causes.

People with alcohol dependence, those with kidney disease, and individuals with autoimmune disorders like celiac or Crohn's disease are at higher risk. Additionally, certain medications can interfere with B6 absorption.

Rich sources of vitamin B6 include poultry, fish (like salmon and tuna), organ meats, bananas, avocados, potatoes, chickpeas, and fortified cereals.

No, while there is some overlap, infants may experience symptoms like irritability, abnormally sensitive hearing, and seizures. Adult symptoms more often include skin rashes, anemia, and confusion.