Published: 18 Jun 2025

ICD9: 266.1      ICD10: E53.1      ICD11: 5B5D

Vitamin B6 deficiency, also known as pyridoxine deficiency, occurs when your body doesn't get enough vitamin B6 (pyridoxine).
Vitamin B6 is a water-soluble vitamin that plays a crucial role in many bodily functions, including:

Brain development and function: It's involved in the production of neurotransmitters like serotonin, dopamine, and norepinephrine, which regulate mood, sleep, and cognitive function.
Immune function: It supports the production of white blood cells and antibodies.
Metabolism: It's necessary for the metabolism of proteins, carbohydrates, and fats. It helps convert stored carbohydrates into energy and is involved in gluconeogenesis (making glucose from non-carbohydrate sources).
Hemoglobin formation: It is required for the production of hemoglobin, the protein in red blood cells that carries oxygen.

Causes of Vitamin B6 Deficiency:

Inadequate dietary intake: While rare in developed countries, it can occur with poor diets, especially those lacking a variety of fruits, vegetables, and meat.
Malabsorption: Conditions that interfere with nutrient absorption in the intestines, such as Crohn's disease, celiac disease, and ulcerative colitis, can lead to deficiencies.
Alcoholism: Alcohol interferes with the absorption and metabolism of vitamin B6.
Certain medications: Some drugs can interfere with vitamin B6 metabolism, including:
Isoniazid (used to treat tuberculosis)
Penicillamine (used to treat Wilson's disease and rheumatoid arthritis)
Hydralazine (used to treat high blood pressure)
Oral contraceptives (although the link is complex and debated).
Kidney disease: Kidney problems can impair the body's ability to activate vitamin B6.
Genetic disorders: Rare genetic conditions can affect how the body processes vitamin B6.
Hyperthyroidism: Can increase the need for B6.

Symptoms of Vitamin B6 Deficiency:

The symptoms can vary and may be mild or severe depending on the degree of deficiency. Common symptoms include:

Neurological symptoms:
Peripheral neuropathy (nerve damage causing tingling, numbness, and pain in the hands and feet)
Seizures (especially in infants)
Depression
Confusion
Irritability
Headaches
Skin problems:
Seborrheic dermatitis (scaly, oily rash, often on the face, scalp, and chest)
Cheilosis (cracks and sores at the corners of the mouth)
Glossitis (inflammation of the tongue)
Hematological problems:
Microcytic anemia (small, pale red blood cells)
Immune system problems:
Impaired immune function, leading to increased susceptibility to infections.
Nausea and vomiting:
Fatigue:
Weakness:

Diagnosis:

Diagnosis typically involves:

Medical history and physical exam: Your doctor will ask about your diet, medications, and medical history.
Blood tests: Measuring vitamin B6 levels in the blood (plasma pyridoxal-5-phosphate or PLP is the most common measurement). Other tests might include complete blood count (CBC) to check for anemia and tests to rule out other conditions.

Treatment:

The treatment for vitamin B6 deficiency usually involves:

Dietary changes: Eating foods rich in vitamin B6, such as poultry, fish, pork, whole grains, bananas, potatoes, and fortified cereals.
Vitamin B6 supplements: Your doctor may recommend a supplement, often in the form of pyridoxine hydrochloride. The dosage will depend on the severity of the deficiency and the underlying cause.
Addressing the underlying cause: If the deficiency is caused by malabsorption, medication, or another underlying condition, treating that condition is essential. This might involve dietary changes, medication adjustments, or other therapies.

Prevention:

Eat a balanced diet: Focus on consuming a variety of foods that are good sources of vitamin B6.
Consider supplementation if at risk: People with conditions that increase their risk of deficiency, such as alcoholics or those taking certain medications, may benefit from a vitamin B6 supplement under the guidance of a healthcare professional.

Important Considerations:

Excessive intake: While vitamin B6 is generally safe, taking very high doses (especially through supplements) can lead to neurological damage, particularly peripheral neuropathy. It's crucial to follow your doctor's recommendations regarding dosage.
Drug interactions: Vitamin B6 can interact with certain medications. Always inform your doctor about all the supplements and medications you are taking.

Consult a healthcare professional: If you suspect you have a vitamin B6 deficiency, it is essential to consult with a doctor for diagnosis and appropriate treatment. Self-treating with high doses of supplements can be harmful.