The winter season is usually considered peak season for colds and the flu. Although cold and flu season generally occurs between October and March, the worst times for these infections occur during January and February. However, you can take steps to boost your immune system through exercise — and by eating nutrient-rich foods that can strengthen your body and naturally battle disease.

Here are 8 nutrients you can add to your diet to ward off those pesky winter colds.

1. Selenium

Selenium contains properties that play an important role in reproduction, thyroid hormone metabolism, and DNA synthesis, and can protect against infection. The recommended daily intake of selenium is 55 micrograms. Selenium can be found in foods such as tuna, brazil nuts, spinach, baked beans, milk, and other types of seafood and dairy products.

2. Vitamin A

Vitamin A helps maintain the function of major organs, including the heart, lung, and kidneys, and can help regulate cell growth in terms of battling cancer. Women need about 700 micrograms of vitamin A daily, whereas men need about 900 micrograms. Vitamin A can be found in most fruits and vegetables, pistachios, milk, and eggs.

3. Vitamin B2

Vitamin B2, also known as riboflavin, is known for boosting energy, which is important during the chilly winter months. You can increase your vitamin B2 intake by eating higher amounts of eggs and plenty of green vegetables such as asparagus and green beans.

4. Vitamin B6

Vitamin B6 actually consists of six different compounds that support a number of functions in the body, including immune system function. Adults generally need between 1.3 and 2 micrograms of vitamin B6 per day. Examples of foods high in vitamin B6 include raisins, cottage cheese, chickpeas, and bananas.

5. Vitamin C

Although research has not conclusively proven that vitamin C alone boosts immune system function, the vitamin has been shown to reduce illness time, and may work together with other nutrients to boost the immune system. Most fruits and vegetables contain vitamin C, with the richest vitamin C concentration found in tomatoes, strawberries, winter squash, and cantaloupe.

6. Vitamin D

Vitamin D is best known for promoting bone health and preventing osteoporosis, and is usually provided by sun rays. Since the winter months are cold and snowy, it can be hard to get the sunlight exposure needed to ward off infection and disease. Foods rich in vitamin D include cheese, eggs, tuna, and salmon.

7. Vitamin E

Vitamin E has the ability to reduce inflammation and boost the immune system; however, most Americans fail to meet the daily requirements of vitamin E. To boost your vitamin E intake, eat higher amounts of nuts and seeds, and cook using vegetable oils in place of butter and margarine.

8. Zinc

Zinc supports immune cell function and wound healing. Women need about 8 micrograms of zinc daily, whereas men need 11 micrograms daily. Zinc can be found abundantly in oysters, but you can also increase your zinc intake by eating yogurt, cheese, peas, cashews, and kidney beans.