How Smoking Depletes Your Body of Vitamins

More Free Radicals and Fewer Antioxidants

Man smoking a cigarette

As of Dec. 20, 2019, the new legal age limit is 21 years old for purchasing cigarettes, cigars, or any other tobacco products in the U.S.

Cigarette smoke is a toxic blend of poisons and cancer-causing chemicals that put virtually every internal organ at risk when people smoke. It creates an abundance of free radicals that can cause cellular damage and depletes essential vitamins and minerals in our bodies. Let's take a closer look.

Vitamin Depletion

Cigarette smoking speeds up the production of free radicals in your body. These free radicals are what causes damage to cells that can eventually lead to cancer as well as other diseases. Yet even without smoking our bodies are exposed to free radicals every day that are generated by both toxins in our environment and the normal metabolic processes that are used to digest the food we eat.

Vitamins act as a defense against free radicals. They help to neutralize free radicals to prevent or minimize damage. Smoking depletes these shields, making it easier for free radicals to damage the body.

Put together, the combination of increased free radicals caused by smoking and a reduced supply of vitamins also due to smoking packs a double wallop against us. Let's look at what free radicals do to our bodies, the process by which smoking depletes essential vitamins, and how this combination leaves your body vulnerable to damage.

Free Radicals

Free radicals are atoms or molecules that have an odd number of electrons.  Molecules do not like to be in this state (they are much happier when they have a pair of electrons), which makes them very unstable. These unhappy free radicals, therefore, travel around the body looking for an electron to grab from other molecules so that they can stabilize their energy.

Depending on where they find the electron they need, they can wreak havoc on healthy tissue. When they interfere with collagen, they cause the notorious "smoker's wrinkles." When they encounter blood vessels, they can damage the blood vessel lining setting the stage for a heart attack.

And when the source becomes DNA in the cells of our bodies, damage (gene mutations) may occur. It is this accumulation of gene mutations that is responsible for the formation of a cancer cell.


The body's defense system uses antioxidants to combat the damage caused by free radicals. Antioxidants are molecules that are able to donate electrons to free radicals without losing their own molecular integrity. In this way, they are able to slow the destructive impact that free radicals have on the body.

Science has identified upwards of 4,000 antioxidants, some of which are produced in the human body naturally. Others come from the foods we eat.

Two important antioxidant champions are vitamin C and vitamin E. They help fight off inflammation and toxins in the body and are critical for a healthy immune system.

Oxidative Stress

When there are too many free radicals and not enough antioxidants in the body, a condition known as oxidative stress occurs. This is thought to play a part in the development of a whole host of diseases, including cancer and heart disease.

Vitamin C

Vitamin C is a water-soluble vitamin. Unlike fat-soluble vitamins, the body is unable to store water-soluble vitamins and must get them daily from the foods we eat.

Vitamin C is needed to make collagen, a protein responsible for growing and repairing cells in our bodies that produce everything from skin to muscle, and from ligaments to blood vessels. It helps keep our immune system strong and reduces blood sugar. It also has the unique quality of being able to help with the regeneration of other antioxidants such as vitamin E.

Studies have found that people who smoke, and those who are exposed to secondhand smoke, have reduced amounts of vitamin C in their bodies. It's thought that smokers require 35 mg more vitamin C daily than non-smokers.

Unfortunately, simply taking a supplement isn't the answer at least with regard to heart disease. People who took a vitamin C supplement still suffered the damage to blood vessels that occurs with low vitamin C levels. Why this is we aren't sure.

There have been arguments that supplements of vitamin C do not reduce cancer risk and this can be confusing. Overloading the body (taking much more than you need) is not likely to be helpful. But even a small deficiency in vitamin C may put you at greater risk. And since vitamin C levels are lower in people who smoke, this appears to be the case.

In the real world, a 2017 study found that a diet high in vitamin C reduced the risk of lung cancer in female smokers by 26%.

Vitamin C Sources

What does this mean? If you smoke or if you're exposed to secondhand smoke, getting an adequate amount of vitamin C in your diet is extremely important. That said, continued smoking might offset any benefit and smoking cessation is the best solution.

Food Sources of Vitamin C

Vitamin C can be found in all fruits and vegetables. Excellent sources of vitamin C include:

  • Cantaloupe
  • Watermelon
  • Citrus fruits
  • Blueberries, cranberries, strawberries, raspberries
  • Cranberries
  • Strawberries
  • Raspberries
  • Tomatoes
  • Broccoli
  • Brussels sprouts
  • Potatoes (both sweet and white)

Vitamin E

Vitamin E is fat-soluble and is stored in the liver and fat deposits in the body. This means that you do not necessarily need to get vitamin E in your diet every day, but dietary intake is important to maintain your body's supply. Vitamin E is an important nutrient that helps us build red blood cells and bolsters the immune system to fight off viruses and bacteria.

Researchers also suspect that vitamin E plays a role in protecting us from cancer, heart disease, and aging. Vitamin E is one of the first lines of defense against the free radical damage to the lungs when we breathe in air pollution and cigarette smoke. Vitamin E is an antioxidant powerhouse.​

Like vitamin C, smoking appears to increase vitamin E requirements.

Unfortunately, research has not confirmed that vitamin E supplements actually help to prevent cancer, heart disease, or symptoms of aging. In fact, studies suggest that taking more than 400 IU per day of vitamin E may increase certain kinds of heart disease, and increase overall mortality.

There are arguments that the particular type of vitamin E is important, but at the current time, it's best to obtain your vitamin E by eating a sensible diet.

Healthy Sources of Vitamin E

  • Nuts, such as hazelnuts, peanuts, and almonds
  • Vegetable oils, such as safflower, wheat germ, corn, and sunflower
  • Green leafy vegetables such as spinach and broccoli
  • Seeds, such as sunflower seeds
  • Breakfast cereals that have been fortified with vitamin E

Free Radicals

While scientists still have much to learn about the composition of cigarette smoke, we do know there are links between smoking and vitamin depletion, and that this compromises our body's ability to manage the toxins in cigarette smoke. This may predispose us to the diseases that follow tobacco use.

Cigarette smoke is an extremely toxic brew of over 7,000 chemical compounds. Some of the harmful chemicals in cigarette smoke which are poisonous, cancer-causing, or both, include things like:

Cigarette smoke also has radioactive components that produce free radicals as part of their decomposition.

Cigarette smoke is dangerous to breathe in, whether it is firsthand (mainstream smoke) through a burning cigarette, or secondhand from smoke lingering in the air.

If You Smoke

If you smoke, it's never too late to quit, and your body can begin to repair itself beginning immediately. While the risk of lung cancer and some other cancers remains elevated for life (though it decreases substantially by 10 years after quitting) your risk of other smoking-related diseases such as heart disease drops quite rapidly.

Take a moment to look through our quit smoking toolbox to find the tools and motivation needed to make the courageous step to quit.

The Bottom Line

Cigarette smoking increases the generation of free radicals in the body which can predispose to tissue damage resulting in conditions from heart disease to cancer. Antioxidants such as vitamin C and vitamin E are part of our body's defense system, acting to neutralize free radicals before they can do their damage.

Sadly, these vitamins are also depleted in people who smoke yielding a bad combination; more free radicals with fewer antioxidants to fight them. It appears that dietary sources are preferred over supplements, with some studies on supplements of both vitamins showing little effect.

The best option is to quit smoking completely to reduce both the free radicals generated in your body and to increase your body's level of antioxidants.

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9 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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