Does Drinking Alcohol Deplete B12? Here's What the Science Says

November 2, 2025 •

2 min read

According to research published by the National Institutes of Health, up to 25% of individuals with alcoholism experience vitamin B12 deficiency. Yes, drinking alcohol does deplete B12, but the reasons are more complex than simple malnourishment.

Quick Summary

Chronic alcohol consumption significantly impairs the body's ability to absorb, store, and utilize vitamin B12, leading to deficiency. This is primarily due to damage to the stomach and intestines, compromised liver function, and poor dietary habits.

Key Points

Impaired Absorption: Chronic alcohol consumption damages the stomach lining, leading to a reduction in hydrochloric acid and intrinsic factor, both essential for B12 absorption.
Liver Damage: As the primary storage organ for B12, a liver damaged by alcohol has a compromised ability to store and release the vitamin, leading to depleted reserves over time.
Nutritional Displacement: Many heavy drinkers replace nutrient-rich food calories with 'empty' alcohol calories, resulting in an inadequate intake of B12 from their diet.
Accelerated Excretion: The diuretic effect of alcohol can increase the excretion of water-soluble vitamins, including B12, further contributing to deficiency.
Potentially Irreversible Damage: Untreated B12 deficiency, particularly when combined with alcohol-related damage, can lead to severe neurological problems like numbness and memory issues, some of which may be permanent.
Supplementation Needed: For those with alcohol-induced B12 deficiency, high-dose oral supplements or injections are often necessary to effectively replenish the body's stores.

The Direct Impact of Alcohol on B12 Absorption

Alcohol interferes with vitamin B12 absorption at several stages. Its effects target the mechanisms needed for B12 uptake in the gastrointestinal (GI) tract.

Alcohol's Damage to the Stomach and Intestines

Alcohol irritates and inflames the stomach lining, potentially causing gastritis. This condition reduces the production of hydrochloric acid, needed to release B12 from food, and intrinsic factor, required for B12 absorption in the small intestine. Alcohol also damages the intestinal lining, shrinking the villi responsible for nutrient absorption and speeding up bowel transit time, further hindering B12 uptake.

Compromised Liver Storage and Utilization

The liver stores vitamin B12 reserves. However, chronic alcohol use can lead to liver damage like alcoholic hepatitis or cirrhosis. This impairs the liver's ability to store and release B12, potentially causing deficiency over time.

The 'Double-Whammy' Effect

Poor Dietary Intake: Heavy drinkers often consume fewer nutrient-rich foods, lowering B12 intake.
Impaired Metabolism: Alcohol metabolism can interfere with how the body uses absorbed nutrients, worsening the deficiency.

A Vicious Cycle: Alcoholism, Malnutrition, and Neurological Damage

Alcohol's link to B12 depletion is part of a larger nutritional impact. B12 deficiency symptoms like numbness, tingling, and memory problems can worsen neurological damage from heavy alcohol use.

Symptoms of Alcohol-Related B12 Deficiency

Fatigue and Weakness: Often due to anemia.
Neuropathy: Numbness or tingling in extremities.
Cognitive Issues: Poor memory, confusion.
Mood Changes: Irritability, depression.

Comparison: Alcohol's Effect on Nutrients


Feature	Vitamin B12	Folate (B9)	Thiamine (B1)	Zinc	Magnesium
Absorption Impact	Severely impaired due to gastritis and intestinal damage.	Impaired absorption and liver storage.	Impaired absorption and active transport inhibition.	Decreased absorption and increased urinary excretion.	Increased urinary excretion and decreased dietary intake.
Storage Impact	Compromised liver storage due to inflammation and damage.	Decreased hepatic storage.	Impaired liver storage.	Reduced hepatic storage.	No specific storage organ, but depleted quickly.
Utilization Impact	Impaired utilization and transport.	Altered coenzyme activation.	Used up in alcohol metabolism.	Depleted in alcohol metabolism.	Increased excretion during diuresis.

Conclusion: More Than Just Poor Diet

Yes, drinking alcohol depletes B12 through multiple mechanisms, not just poor diet. It damages the stomach, intestines, and liver, hindering B12 absorption and storage. The resulting symptoms, including potentially permanent neurological damage, can be severe. Addressing this requires reducing alcohol intake, dietary changes, and often supplementation to restore function.

For more information on the impact of chronic alcohol use on the body's nutrition, consult resources like the National Institutes of Health.

Disclaimer: This article is for informational purposes only and should not be considered medical advice. If you suspect you have a vitamin B12 deficiency or an alcohol use disorder, please consult a healthcare professional.

How to Manage Alcohol-Related B12 Depletion

Reduce or Eliminate Alcohol: Stopping or reducing alcohol helps the body recover.
Consult a Doctor: Get diagnosed and discuss treatment options like supplements or injections.
Enhance Diet: Eat B12-rich foods (meat, fish, eggs, dairy, fortified foods).
Consider Supplementation: A doctor may prescribe high-dose supplements or injections.
Prioritize Nutrient-Dense Foods: Maintain a balanced diet.

Frequently Asked Questions

Yes, even moderate alcohol consumption can interfere with B12 absorption. Studies have shown that consuming just one to two drinks a day can lower B vitamin levels over time.

Alcohol inflames the stomach lining (gastritis), reducing the production of hydrochloric acid and a protein called intrinsic factor, which are both essential for releasing and absorbing B12.

The body stores a large reserve of B12 in the liver, so a deficiency might not become apparent for several years. However, chronic or heavy alcohol use accelerates depletion by hindering absorption and damaging the liver's storage capacity.

B12 injections can be an effective treatment for correcting the deficiency and may help alleviate neurological symptoms. However, if significant nerve damage has already occurred, it may not be entirely reversible.

Oral supplements, often at high doses, can be effective in replenishing B12 levels in individuals with alcoholism, especially once they have stopped drinking. In severe cases, injections may be used for a quicker response.

Alcohol impacts nutrition in multiple ways beyond B12, including poor diet and interference with the absorption, transport, and utilization of many other vitamins and minerals, such as thiamine, folate, and zinc.

The liver stores and manages B12. Chronic alcohol consumption damages the liver, impairing its ability to perform these functions, which in turn leads to a reduction in the body's B12 reserves.