It's no surprise that cigarette smoking or living under constant stress are bad for your health, but did you know that one way they have a negative impact is by robbing you of needed nutrients? In fact, there are plenty of things that steal nutrients from the healthy foods you eat. Known as nutrient thieves, these habits and foods should be on your radar.

Cigarette smoke

Former smokersBreaking the cigarette habit will not only stop toxins from entering your body, it will better enable your body to absorb nutrients that can keep you healthier. (Photo: Dmytro Zinkevych/Shutterstock)

Smokers have more difficulty absorbing nutrients than non-smokers. In addition to absorbing the toxins from cigarette smoke, smokers are inhaling nutrient thieves that rob them of some of the vitamins and minerals that are necessary to fight off the ill effects of smoking. One cigarette robs the body of 25 milligrams of the antioxidant vitamin C, the amount in an orange, according to Respiratory Health Association of Metropolitan Chicago. So, in addition to introducing cancer-causing agents through inhaling smoke, one of the nutrients that could help fight off cancer gets depleted with each puff.

Smoking also can rob the body of vitamin D, a nutrient that helps develop strong immune systems, prevent autoimmune disorders, and regulate the release of insulin. Vitamin D also helps the body absorb bone-strengthening calcium, so smoking leads to a higher risk of osteoporosis.

Caffeine

black coffeeAdding a little milk to black coffee will most likely cancel out its caffeine-depleting effects. (Photo: Julius Schorzman/Wiki Commons)

Caffeine can deplete calcium. A cup of coffee that has 60-120 mg of caffeine can deplete your body of 2-4 mg of calcium, according to Nestle. However, there's about 35 mg of calcium in 1 ounce of 1 percent milk, so those who add milk to their caffeinated coffee or tea probably don't need to worry about how it affects calcium absorption. Those who don't add milk or a milk substitute that contains calcium, or those who drink caffeinated beverages without milk (sodas, iced teas, energy drinks) may be robbing their bodies of calcium.

Like cigarette smoke, caffeine can also rob your body of vitamin D, and studies have shown that it may increase the rate of bone loss in elderly women.

Heavy caffeine users should consider cutting back or adding foods high in vitamin D to their diet like oily fish, portobello mushrooms and tofu.

Alcohol

several glasses of red wineOne glass of wine a day probably won't be too much of a problem if you're eating a diet high in vitamins and minerals, but four glasses a day could be robbing the body of essential nutrients. (Photo: Africa Studio/Shutterstock)

Heavy alcohol consumption acts as a nutrient thief in several ways, according to SFGate. The liver's stores of essential vitamins and minerals get used up by the liver when it's working to metabolize alcohol. Alcohol also has diuretic effects, causing minerals like zinc, magnesium and potassium to pass through the body instead of being absorbed. Over time, alcohol can damage the stomach, impeding its ability to absorb essential nutrients.

Heavy drinkers should cut back on their alcohol intake. Moderate drinkers should make sure they eat a diet of whole foods that are high in essential vitamins and minerals to make sure they're replacing whatever the alcohol depletes.

Sugar

different types and forms of sugarSugar takes many forms, and all of them can be nutrient thieves. (Photo: alexpro9500/Shutterstock)

In all its forms — white table sugar, honey, maple syrup, agave, evaporated cane juice and more — sugar is a nutrition thief, according to Shape. Don't think that it's only found in candy, cakes and soda, though. It's also found in surprisingly high amounts in foods like marinara sauce and flavored yogurt.

Like cigarette smoking, sugar robs your body of vitamin C, and like caffeine it can rob your body of calcium, so both your immune system and bone strength can be affected. Sugar also can stop your body from absorbing magnesium, a nutrient important for brain development and memory.

Try these tips for kicking the refined sugar habit to lessen your intake of sugar and increase the absorption of essential nutrients in your body.

Stress

Stressed out woman at workStress doesn't affect just your concentration. It can have damaging health effects, too. (Photo: sheff/Shutterstock)

Stress does damage to the body like elevating your blood pressure and increasing your heart rate. Prolonged stress can also stop your body from absorbing nutrients properly, according to Sakara Life. When your body is in stress mode, it can halt digestion and disrupt the work of digestive enzymes and the production of hydrochloric acid, both of which help your body absorb nutrients from food.

Staying out of stressful situations is one way to make sure stress doesn't become a nutrient thief, but that isn't always possible. Finding ways to reduce the stress you're feeling is possible. Practices like deep breathing and getting enough sleep can help reduce work stress and meditation can be good for reducing the effects of all types of stress.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.