woman sneezing into tissue

Immune System and Florida Orange Juice

Nutrition is Important

Florida Orange juice provides a variety of vitamins and nutrients that are part of a healthy, balanced diet for a strong immune system.

  • Vitamin C may come to mind when you think about nutrition and the common cold. Vitamin C is a dietary antioxidant1, which can help protect you from different health conditions. One 8-ounce glass of OJ provides more than 100% of your recommended Daily Value, making orange juice an excellent source of vitamin C.*
  • Vitamin D is known to help build strong bones and teeth.1 Research is looking at how vitamin D might play a role in regulating our immune responses and helps immune cells fight off bacteria and viruses that get into the body. Some varieties of fortified orange juice are a good source of vitamin D, providing 15% of the Daily Value in an 8-ounce glass.*
  • Beneficial plant compounds found in orange juice, such as flavonoids and colorful carotenoids, are being studied for their potential benefit on our immune system.

Florida OJ as part of a healthy diet and lifestyle may help support overall health and wellbeing. It’s a great source of vitamin C, vitamin D and other beneficial plant compounds which can keep you hydrated and help get you through the cold and flu season.

Learn more about how you can support your immune system here 

In Orange Text is the phrase "Did you know?"

Citrus juices are reported to be a major contributor of vitamin C in the diet. 2

Nutrition Research Corner for Health Professionals

Vitamin C

Vitamin C behaves as an antioxidant by scavenging Reactive Oxidative Species (ROS) and works with powerful antioxidant enzymes in the body and with vitamins (e.g. glutathione, vitamin E).3-5 Vitamin C is particularly important to the immune system as it stimulates the production and function of white blood cells and protects cells against ROS that are generated from activation of white blood cells as a result of infection and inflammatory stress.4-5

Histamine is a compound released by cells in response to allergic and inflammatory reactions. It’s involved in the presentation of symptoms such as nasal stuffiness, runny nose, teary eyes, and coughing. Vitamin C is thought to have an anti-histamine effect,6 which may help lessen cold symptom severity.5,7

Results from some studies show that immune functions improve with increased vitamin C intake, while other studies show no effect. The inconsistency may be due to the use of adequately nourished study participants, or because leukocytes saturate with vitamin C at a lower intake than is required to saturate plasma (~100 mg/day).5

In a Cochrane review and meta-analysis combining 29 studies,8 prophylactic vitamin C supplementation reduced the incidence of colds by 52 percent in participants undergoing heavy physical stress (e.g., marathon runners, soldiers in subarctic conditions, skiers), while the effect was not significant in the pooled general community trials (RR 0.97 (0.94 to 1.00). Vitamin C administration also reduced cold duration by 14 percent in children and 8 percent in adults, and reduced cold severity in 31 comparisons of 9,745 cold episodes. However, therapeutic trials were inconsistent in these effects.

Vitamin D

Vitamin D strongly modulates the immune system. Many immune cells express vitamin D–activating enzymes allowing them to convert vitamin D precursors to the active form of vitamin D.This promotes antibacterial responses to pathogens by modulating CD4+ T-cell functions and allows epithelial cells to mount an antibacterial response.9

Multiple studies have found associations between low vitamin D and increased risk of infections, including influenza and other respiratory infections and sepsis.9 Several meta-analyses have shown mixed results regarding the effectiveness of vitamin D supplementation and improved resistance to respiratory infection. However, many other studies showed positive benefits of vitamin D on respiratory infection, particularly in people with low vitamin D status.9

Fortified orange juice varieties often provide vitamin D along with calcium needed for strong bones.

Bioactive Plant Compounds

Many carotenoids found in 100% orange juice, including beta-carotene, alpha-carotene and beta-cryptoxanthin, can form vitamin A in the body which is important for immune function.10 Vitamin A is necessary for epithelial cell health, gene expression and immune function.11 Carotenoids have shown to have antioxidant properties and help reduce inflammation, as well as aid in the immune system.10,11 Hundreds of studies have shown carotenoids from foods (found in high amounts in fruits and vegetables) to be associated with lower risk of many diseases including macular degeneration, cardiovascular disease and many cancers including of the prostate, breast, cervix and lung.10,12

Research supports the role of flavonoids in the immune system. In human clinical studies, hesperidin in orange juice exerted positive changes in antioxidant enzymes, altered white blood cell gene expression to anti-inflammatory profiles, and lowered oxidative stress biomarkers that protect against DNA damage and lipid peroxidation.13,14 A systematic review of randomized controlled trials testing flavonoids’ effects on the respiratory and immune system function found that among those who consumed flavonoids, there was a 33 percent decrease in upper respiratory tract infections in comparison to those who did not consume flavonoids.15

The flavonoid hesperidin is highly concentrated in citrus and rarely found in other foods,16 making orange juice a unique source.

* Values based on a 2000 calorie diet. Nutrient values may vary based on manufacturer, brand and product types.


  1. Canadian Food Inspection Agency (2018, May 11): Nutrient Function Claims. Retrieved June 12, 2019 from http://www.inspection.gc.ca/food/general-food-requirements-and-guidance/labelling/for-industry/health-claims/eng/1392834838383/1392834887794?chap=9
  2. Chun et al. J Nutr. 2010;140:317-324.
  3. Lykkesfeldt et al. Adv Nutr 2014; 5:16-18.
  4. Vitamin C. Linus Pauling Institute Micronutrient Information Center. Oregon State University. http://lpi.oregonstate.edu/mic/vitamins/vitamin-C
  5. Food and Nutrition Board, Institute of Medicine. Vitamin C. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, D.C.: National Academy Press; 2000:95-185.
  6. Vitamin C Fact Sheet for Health Professionals. Office of Dietary Supplements. National Institute of Health. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
  7. Johnston et al. Subcell Biochem 1996;25:189-213.
  8. Hemila et al. Cochrane Database Syst Rev. 2013(1):Cd000980.
  9. Lang et al. Clin Thera. 2017; 39(5):930-945.
  10. Carotenoids, In: Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Institute of Medicine. The National Academies Press, Washington, DC. 2000.
  11. Vitamin A, In: Dietary Reference Intakes. Institute of Medicine. The National Academies Press, Washington, DC. 2006.
  12. Carotenoids. Linus Pauling Institute. Oregon State University. http://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/carotenoids
  13. Rangel-Huerta et al. J Nutr. 2015;145(8):1808-1816.
  14. Milenkovic et al. PLoS One. 2011;6(11):e26669.
  15. Somerville et al. Adv Nutr. 2016;7(3):488-497.
  16. Bhagwat S, Haytowitz D. USDA Database for the Flavonoid Content of Selected Foods Release 3.2. In. Beltsville, MD: Unites States Department of Agriculture; 2015.