Why Am I Not Absorbing B6? Causes, Symptoms, and Solutions

January 6, 2026 •

3 min read

According to the Centers for Disease Control and Prevention, up to 10% of Americans may be deficient in vitamin B6, a vital nutrient for metabolic and neurological health. You might be asking, "Why am I not absorbing B6?" even when you think you're getting enough from your diet, pointing to underlying issues beyond simple intake.

Quick Summary

This article explores the common and less-known reasons for poor vitamin B6 absorption. It details how malabsorption disorders, chronic diseases, certain medications, and lifestyle factors can interfere with this essential nutrient's uptake. Practical solutions for improving your B6 status are also discussed.

Key Points

Underlying Malabsorption: Chronic conditions like celiac disease, Crohn's disease, and post-bariatric surgery can prevent proper vitamin B6 absorption.
Chronic Illness Impact: Kidney disease, liver disease, and autoimmune disorders such as rheumatoid arthritis can disrupt B6 metabolism and increase its clearance.
Medication Interference: Certain drugs, including some anticonvulsants, the antibiotic isoniazid, and oral contraceptives, can block B6 absorption or deplete its levels.
Alcohol and Diet: Chronic alcohol abuse significantly impairs B6 absorption and increases its breakdown, while a diet consisting of primarily processed foods can lead to inadequate intake.
Active Supplement Form: For better bioavailability, especially in cases of impaired liver function, supplementing with the active coenzyme form, pyridoxal 5'-phosphate (P5P), may be more effective than standard pyridoxine HCl.
Symptoms to Monitor: Symptoms of a B6 deficiency include skin conditions like dermatitis, neurological issues like tingling in the extremities, mood changes, and a weakened immune response.
Stomach Acid's Role: An acidic stomach environment is essential for freeing B6 from food; long-term use of acid-blocking medication may reduce absorption.
Consult a Professional: Due to the complexity of B6 absorption issues, a healthcare provider should be consulted for proper diagnosis and a personalized treatment plan.

Common Reasons You Aren't Absorbing B6

Vitamin B6, or pyridoxine, is a water-soluble vitamin critical for over 100 enzyme reactions, including protein and carbohydrate metabolism, brain function, and immune health. Unlike fat-soluble vitamins, your body does not store large reserves of B6, making consistent intake and efficient absorption essential. If you're experiencing symptoms of a deficiency despite adequate dietary intake, a deeper issue with absorption may be at play.

Gastrointestinal and Malabsorption Disorders

Conditions affecting the small intestine can hinder B6 uptake.

Celiac Disease: Damages the intestinal lining, impairing nutrient absorption, including B6.
Crohn's Disease and Ulcerative Colitis: These inflammatory bowel diseases (IBDs) cause chronic inflammation and can lead to malabsorption.
Bariatric Surgery: Can alter the digestive system, reducing the area for absorption and requiring lifelong supplementation.

Chronic Health Conditions

Systemic diseases can interfere with B6 metabolism.

Kidney Disease: Can lead to excessive excretion of B6, causing low levels.
Autoimmune Inflammatory Disorders: Increase the metabolic clearance of B6.
Alcohol Dependence: Impairs B6 absorption and increases its breakdown.

Medication Interactions

Several medications can disrupt B6 metabolism and absorption.

Isoniazid: Can inhibit B6 activity.
Oral Contraceptives: Some can lower B6 levels.
Antiepileptic Drugs: Can increase B6 breakdown.

The Importance of Stomach Acid

Pryidoxine needs an acidic environment for proper release and absorption. Long-term use of acid-inhibiting medications may impact this.

Comparison of B6 Supplement Forms

Choosing the right supplement form can be important for those with compromised absorption. Pyridoxine hydrochloride is common, but pyridoxal 5'-phosphate (P5P) is the active form and may offer better bioavailability for some.


Feature	Pyridoxine Hydrochloride (HCl)	Pyridoxal 5'-Phosphate (P5P)
Absorption	Absorbed well by passive diffusion in the jejunum.	Absorbed directly; may be beneficial for those with impaired liver function.
Conversion	Requires conversion to active P5P by the liver.	The active, pre-converted form.
Effectiveness	Highly effective for most with sufficient liver function.	Potentially more effective for individuals with metabolic issues.
Commonality	Most common form in multivitamins.	Available in targeted supplements.

Strategies for Improving B6 Absorption

Strategies to improve B6 status include:

Dietary Adjustments: Focus on foods with high bioavailability, like animal products and starchy vegetables.
Supplementation: A healthcare provider may recommend supplements. P5P may be better for those with liver issues.
Address Nutrient Deficiencies: Deficiencies in other nutrients, like B2, can impair B6 conversion.
Manage Alcohol Intake: Reducing alcohol is critical for those with alcohol dependence.
Review Medications: Consult a doctor about potential B6-depleting effects of medications.

Conclusion

Persistent low B6 levels may indicate problems with absorption or metabolism beyond inadequate intake. Chronic conditions, malabsorption disorders, autoimmune issues, medication interactions, and heavy alcohol use can all interfere with B6 utilization. For those with absorption issues, choosing the right supplement, like P5P, and managing underlying conditions are key steps. It's recommended to work with a healthcare provider for diagnosis and treatment.

Potential Symptoms of B6 Deficiency

Symptoms of B6 deficiency due to poor absorption can include:

Anemia
Skin conditions (rashes, cracked lips, swollen tongue)
Neurological problems (numbness, tingling, confusion, depression)
Weakened immune system
Irritability and mood changes

Seeking Professional Guidance

If you suspect poor B6 absorption or have symptoms, seek medical advice. A healthcare provider can diagnose the issue and create a personalized plan.

Frequently Asked Questions

The primary cause often involves malabsorption syndromes, such as celiac disease, or chronic conditions like kidney disease and alcoholism that interfere with the body's ability to process and absorb the vitamin, even with adequate dietary intake.

Yes, several medications can interfere with B6 metabolism, including isoniazid, certain antiepileptic drugs (phenytoin), and some oral contraceptives, leading to reduced B6 levels over time.

Symptoms can include skin issues (dermatitis, cracked lips), neurological problems (numbness, tingling, confusion), depression, and a weakened immune system.

Yes, the bioavailability of B6 varies between food sources. Animal products like fish and organ meats have high bioavailability, while plant-based sources contain glycosylated forms that are less readily absorbed.

Not always. For individuals with malabsorption issues, chronic diseases, or metabolic problems, a standard pyridoxine HCl supplement may not be fully utilized. The active form, P5P, might be more effective in these cases.

Bariatric surgery alters the digestive tract, reducing the area available for nutrient absorption. This makes it challenging to absorb sufficient B6 from diet alone and often requires lifelong supplementation.

Yes, chronic alcohol consumption is a major cause of B6 deficiency. It impairs the vitamin's absorption in the intestines and increases its breakdown in the body.

The choice depends on your specific needs. Pyridoxine HCl works for most people, but P5P is the active form and might be a better option if you have impaired liver function or known metabolic issues that hinder conversion.