Having a strong immune system is vital to our existence on earth. Our immune system protects us from pathogens that can leave us vulnerable to getting sick. We often think of a weakened immune system in relation to catching a cold or getting the flu.
However, a weak immune system can also lead to much more serious conditions like allergies, asthma, immune deficiency disorders (like HIV), and autoimmune diseases (1).
In this day and age with all of the convenience foods we have access to, most people do eat enough whole foods including fresh fruits, vegetables and other healthy food sources of protein, fats, and carbohydrates (2). I often hear people say they are going to eat food high in Vitamin C or Zinc to ward off getting a cold in the winter.
Unfortunately, this is not the best way to boost your immune system. “A truly healthy immune system depends on a balanced mix of vitamins and minerals over time, plus normal sleep patterns and a hefty dose of exercise” (2).
When possible, it is always best to get your vitamins and minerals from foods rather than supplements. However, you should talk to your health care provider or nutritionist to see if you may need extra supplementation of certain nutrients. If you do need to take a supplement, be sure you are taking a high-quality supplement from a reputable and well researched source.
Some of the most important nutrients that help with keeping your immune system strong includes: Vitamin C, Vitamin E, Vitamin A, Vitamin D, Folate, Iron, Selenium, and Zinc. Here is a bit more detail on why each nutrient is important and the best food sources for each.
Vitamin C acts as an antioxidant and helps the body fight infections (2). Given Vitamin C acts as an antioxidant, it may play a role in delaying or totally inhibiting the development of certain cancers, cardiovascular disease, and other diseases related to oxidative stress (3). Vitamin C also helps with the absorption of non-heme iron (plant sources of iron) (3).
Food Sources: Citrus fruits (oranges, grape fruit, kiwi), leafy green vegetables (spinach, kale), bell peppers, brussel sprouts, strawberries, papaya, broccoli (2, 3)
Vitamin E acts like a powerful antioxidant like Vitamin C (2). In regards to its role in the immune system, Vitamin E prevents the activity of protein kinase C which is an enzyme that is involved in cell proliferation and differentiation in smooth muscle cells, platelets, and monocytes (3).
Food Sources: Wheat germ, almonds, peanuts, hazelnuts, sunflower seeds, spinach, broccoli, kiwi (2, 3)
Vitamin A also acts as an antioxidant (2). Vitamin A helps to support the growth of cells and cell differentiation. It also plays a critical role in the normal formation and maintenance of the heart, lungs, kidneys, and other organs (3).
Food sources: carrots, sweet potato, pumpkin, cantaloupe, squash, beef liver, red peppers, mango (2, 3)
Vitamin D can help to regulate the innate and adaptive immune responses in the body. Studies have found that having a deficiency in Vitamin D is correlated with an increase in autoimmunity and increases a person’s risk of developing an infection to a pathogen (5).
Food sources: Fatty fish (salmon, mackerel, tuna, sardines), fortified foods (milk orange juice, cereals) (2)
Folate helps make and repair DNA in the body, so it makes sense that a Folate deficiency could weaken a person’s immune system (4).
Food sources: leafy green vegetables, beans, peas, fortified foods (breads, cereal, pasta, rice), beef liver (2, 3)
Iron plays an important role in that it helps to carry oxygen to the cells throughout the body (2)
Food sources: Lean meats (beef, poultry), seafood, beans, spinach, kale, broccoli, oysters, lentils, tofu, chickpeas, cashews, fortified foods (cereals) (2, 3)
Selenium can slow down the body’s over-active immune response to some aggressive types of cancer (2).
Food sources: Garlic, broccoli, sardines, tuna, brazil nuts, barley, halibut, sardines, eggs (2, 3)
Zinc has the ability to slow down the immune response and also plays a role in controlling inflammation (2).
Food sources: Oysters, crab, lean meats (beef, poultry), baked beans, yogurt, chickpeas (2)
*Individual needs may vary. Please speak with your health care provider or nutritionist for your personalized recommendations.
About the Author: Leanne DiMaio earned her Master’s degree in Applied Clinical Nutrition from New York Chiropractic College in December 2017. She is currently working on her Doctorate degree in Clinical Nutrition degree at Maryland University of Integrative Health. Leanne is passionate about helping others achieve their optimal state of health and wellness. She is currently earning clinical hours toward the Certified Nutrition Specialist (CNS) credential under Kim Ross's supervision.
1. MedlinePlus. Immune System and Disorders | Autoimmune Disease. Medlineplus.gov. https://medlineplus.gov/immunesystemanddisorders.html. Published 2018. Accessed August 5, 2018.
2. Cleveland Clinic. 8 Vitamins & Minerals You Need for a Healthy Immune System. Health Essentials from Cleveland Clinic. https://health.clevelandclinic.org/eat-these-foods-to-boost-your-immune-system/. Published 2015. Accessed August 12, 2018.
3. United States Department of Agriculture. Vitamins and Minerals | Food and Nutrition Information Center. Nalusda.gov. 2018. Available at: https://www.nal.usda.gov/fnic/vitamins-and-minerals. Accessed June 3, 2018.
4. Harvard Publishing. Ask the doctor: Does folic acid improve immunity? - Harvard Health. Harvard Health. https://www.health.harvard.edu/womens-health/does-folic-acid-improve-immunity. Published 2015. Accessed August 12, 2018.
5. Aranow C. Vitamin D and the Immune System. Journal of investigative medicine : the official publication of the American Federation for Clinical Research. 2011;59(6):881-886. doi:10.231/JIM.0b013e31821b8755.
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