What Vitamins Are You Deficient in if You're a Smoker?

October 1, 2025 •

2 min read

According to a study cited by the National Institutes of Health, people who smoke have lower plasma and leukocyte vitamin C levels compared to non-smokers due to increased oxidative stress. This rapid depletion is one of several nutritional problems caused by smoking, impacting crucial vitamins and minerals in the body.

Quick Summary

Smoking causes vitamin deficiencies, particularly affecting levels of vitamins C, E, D, and B vitamins like folate and B12, due to oxidative stress and impaired absorption. Addressing these nutritional gaps can support overall health and recovery.

Key Points

Vitamin C: Smokers have significantly lower levels of this crucial antioxidant due to increased oxidative stress from cigarette smoke and may require 35mg more daily.
Vitamin E: The body's primary lipid antioxidant is depleted faster in smokers, and its depletion is worsened by low Vitamin C levels.
B Vitamins: Components in smoke can inactivate folate (B9) and B12, potentially leading to elevated homocysteine levels and increased cardiovascular risk.
Vitamin D: Adult smokers often have lower circulating Vitamin D levels, which may affect lung function and overall health.
Supplements vs. Food: While some vitamins can be supplemented under a doctor's advice, obtaining nutrients from a balanced diet is safer, especially given the increased lung cancer risk associated with high-dose beta-carotene supplements in smokers.
Quitting is Paramount: No vitamin supplement can undo the damage of smoking. The most effective way to improve nutritional deficiencies and health is to quit smoking entirely.

The Core Issue: How Smoking Leads to Vitamin Deficiency

Cigarette smoke contains a vast number of chemicals, many of which are free radicals. These free radicals cause oxidative stress, an imbalance that overwhelms the body's natural antioxidant defenses. Vitamins often act as antioxidants, helping to neutralize these damaging free radicals.

Smoking accelerates the depletion of these vital nutrients as they are used up rapidly to combat the high levels of oxidative stress. Smokers may also consume fewer nutrient-rich foods and certain toxins in smoke can hinder the absorption or utilization of vitamins.

Key Vitamins You Are Deficient in as a Smoker

Vitamin C (Ascorbic Acid)

Vitamin C is a key water-soluble antioxidant depleted by smoking. Studies consistently show lower levels in smokers, necessitating a higher daily intake to counteract oxidative stress.

Vitamin E

A primary antioxidant in fatty tissues, Vitamin E is used up faster in smokers. Low Vitamin C levels can further accelerate Vitamin E depletion.

B Vitamins (Folate, B6, and B12)

Chemicals in smoke can inactivate B vitamins, particularly folate and B12, potentially leading to elevated homocysteine levels and increased cardiovascular risk.

Vitamin D

Smokers often exhibit lower circulating Vitamin D levels, possibly due to interference with its metabolism, reduced dietary intake, or less sun exposure. Low levels are linked to decreased lung function.

Beta-Carotene (Precursor to Vitamin A)

Smokers typically have lower plasma beta-carotene levels. Crucially, high-dose beta-carotene supplements may increase lung cancer risk in smokers and should be avoided. Safe intake is achieved through food sources.

Comparison of Key Deficiencies in Smokers vs. Non-Smokers


Nutrient	Impact on Smokers	Impact on Non-Smokers
Vitamin C	Lower plasma levels; higher daily intake needed due to oxidative stress.	Normal levels with standard diet.
Vitamin E	Faster depletion due to oxidative stress.	Normal turnover.
B Vitamins	Reduced folate and B12; potential for increased cardiovascular risk.	Stable levels with normal diet.
Vitamin D	Often lower circulating levels; linked to reduced lung function.	Higher levels with adequate sun/diet.
Beta-Carotene	Lower plasma levels; high-dose supplements are risky.	Normal levels from diet; supplements typically safe.

How to Address Nutritional Deficiencies from Smoking

The most important action is quitting. Alongside cessation, dietary improvements can help:

Vitamin C: Eat citrus fruits, bell peppers, broccoli, and tomatoes.
Vitamin E: Consume nuts, seeds, vegetable oils, and leafy greens.
B Vitamins: Include leafy greens, beans, salmon, eggs, and fortified foods.
Vitamin D: Get safe sun exposure and eat fatty fish, fortified dairy, and eggs. Consult a doctor about supplements if needed.
Beta-Carotene: Safely obtain from sweet potatoes, carrots, and dark leafy greens; avoid high-dose supplements.

Conclusion: The First and Most Important Step Is Quitting

While improving nutrition supports health, it cannot undo the harm from smoking. Quitting is essential for the body to recover. A healthy diet after quitting helps replenish depleted vitamins and supports overall well-being. For quitting resources, visit the CDC's Smoking & Tobacco Use website or consult a healthcare professional.

CDC: Smoking & Tobacco Use

Frequently Asked Questions

Oxidative stress is an imbalance caused by an excess of free radicals in the body. Smoking introduces a massive amount of free radicals, overwhelming the body's natural antioxidant defenses and leading to cellular damage.

No. While vitamins can help support the body's antioxidant defenses, no amount of vitamin supplementation can prevent or eliminate the significant health problems caused by smoking, such as cancer, heart disease, and lung damage.

High-dose beta-carotene supplements have been linked to an increased risk of lung cancer in smokers. Instead of supplements, smokers should obtain beta-carotene safely through dietary sources like sweet potatoes and carrots.

Components of cigarette smoke can inactivate B vitamins like folate, B6, and B12, which are essential for regulating homocysteine. This inactivation can lead to higher homocysteine levels, increasing the risk of cardiovascular disease.

Yes. After quitting, your body's vitamin levels will begin to normalize as the oxidative stress decreases and your body's absorption improves. Combining cessation with a healthy, vitamin-rich diet can accelerate this recovery process.

For most nutrients, increasing your intake of whole foods rich in those vitamins is the safest and most effective approach. For some specific, severe deficiencies, a doctor may recommend a supplement. Always consult a healthcare provider before starting any new supplement regimen.

Yes. People exposed to secondhand smoke also experience some reduction in antioxidant levels, including Vitamin C. This highlights the importance of protecting yourself and others from tobacco smoke exposure.