According to the CDC, six deaths and over 100 confirmed cases of the coronavirus have been confirmed within the US as of 3/3/20.

A virus is an infectious agent that replicates within cells, which can turn into a disease. We can invest in our health to help prevent ourselves from developing an illness or disease. Not only can a healthy diet prevent certain chronic diseases such as diabetes, but it can also strengthen our immune system.

Your immune system helps fight off a virus by creating a barrier that prevents the virus or bacteria from entering your body. However, if you have a weak immune system, you will have a more difficult time fighting off a virus or bacteria.

If the virus or bacteria enters your body, your immune system tries to detect the virus or bacteria and fight it off before it can reproduce. If the virus or bacteria does reproduce, then it is your immune system’s job to get rid of this virus or bacteria.

Vitamin C, Zinc, and Magnesium

Vitamin C, zinc, and magnesium are all important vitamins/minerals for your immune system’s health due to their antioxidant properties.

Vitamin C is known for its immune defense mechanisms, wound healing properties, protein synthesis and is required for the synthesis of collagen and certain neurotransmitters.1,2

Below are the Recommended Dietary Allowances (RDAs) for Vitamin C. The RDA is the average daily level that is sufficient to meet the nutrient requirements of 97-98% healthy individuals:2

  • 14–18 years:
  • 75 mg (male)
  • 65 mg (female), 80 mg (pregnancy), 115 mg (lactation)
  • 19+ years:
  • 90 mg (male)
  • 75 mg (female), 85 mg (pregnancy), 120 mg (lactation)

healthy eating immune system

Vitamin C food sources:

  • Oranges, grapefruit, strawberries, cantaloupe, tomatoes, red and green peppers, broccoli, Brussel sprouts, cabbage, cauliflower, potato

Zinc is also another nutrient common in a healthy diet that can reduce the duration of a common cold.3 Zinc plays a role in several aspects of cellular metabolism, immune function, wound healing, growth, and development, and is required for proper taste, smell, and protein synthesis.4

RDAs for Zinc:4

  • 14–18 years:
  • 11 mg (male)
  • 9 mg (female), 12 mg (pregnancy), 13 mg (lactation)
  • 19+ years:
  • 11 mg (male)
  • 8 mg (female), 11 mg (pregnancy), 12 mg (lactation)

Zinc food sources:

  • Cashews, chickpeas, yogurt, and milk products, dark chocolate, pumpkin seeds, whole grains, and ready-to-eat breakfast cereals (fortified with zinc), seafood, poultry, eggs, legumes (beans and peas), nuts, oysters, red meat

Magnesium is also known to play a role in the immune response.5 Magnesium takes part in several reactions in the body including protein synthesis, nerve function, muscle function, blood pressure regulation, synthesis of DNA and RNA, takes part in the active transport of calcium and potassium, and has several antioxidant properties.6

RDAs for Magnesium:6

  • 14-18 years:
  • 410 mg (males)
  • 350 mg (females), 400 mg (pregnancy), 360 mg (lactation)
  • 19-30 years:
  • 400 mg (males)
  • 310 mg (females), 350 mg (pregnancy), 310 mg (lactation)
  • 31- 50 years:
  • 420 mg (males)
  • 320 mg (females), 360 mg (pregnancy), 320 mg (lactation)
  • 51+ years:
  • 420 mg (males)
  • 320 mg (females)

Magnesium food sources:

  • Almonds, spinach, whole grains, cashews, peanuts, fortified breakfast cereals, black beans, peanut butter, avocado, dark chocolate, brown rice, plain yogurt, banana, kidney beans, salmon chicken, broccoli, apples, tofu


Try to get in more vitamin C, zinc, and magnesium-rich foods to help build your immune system! Making sure to eat healthy on a regular basis is an important step to feeling your best and not getting sick. The Registered Dietitians at Behavioral Nutrition understand that everyone’s diet is unique and some people have more trouble maintaining a healthy diet. Contact us today to learn more about how we can help you eat healthily and strengthen your immune system.


  1. Carr AC, Maggini S. Vitamin C and immune function. Nutrients. 2017;9(11):1211. https://www.ncbi.nlm.nih.gov/pubmed/29099763. doi: 10.3390/nu9111211.
  2. Vitamin C. U.S. Department of Health and Human Services Website – National Institutes of Health Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/. Updated July 9, 2019. Accessed February 10, 2020.
  3. Singh M, Das RR. Zinc for the common cold. Cochrane Database of Systematic Reviews. 2015;2015(4). doi: 10.1002/14651858.CD001364.pub5.
  4. Zinc. U.S. Department of Health and Human Services Website – National Institutes of Health Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/. Updated July 10, 2019. Accessed February 10, 2020.
  5. Tam M, Gómez S, González-Gross M, Marcos A. Possible roles of magnesium on the immune system. European Journal of Clinical Nutrition. 2003;57(10):1193-1197. doi: 10.1038/sj.ejcn.1601689.
  6. Magnesium. Department of Health and Human Services Website – National Institutes of Health Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/#h1. Updated October 11, 2019. Accessed February 10, 2020.