Open Immune System on the body map
Body system
Immune System
Open the Immune System on the body map
The cells and tissues that recognize and respond to what shouldn't be there.
How nutrients support this system
Each nutrient plays a different part. Open a profile to follow the process, its sources and the foods that carry that nutrient.
- Vitamin CVitamin C helps immune cells carry out activities such as engulfing microbes. It also supports tissue barriers, part of the body's first line of defense.
- Vitamin AVitamin A helps maintain protective tissue linings and supports immune function. Those barriers help keep microbes from entering the body.
Explore the scientific terms
Functions associated with nutrients in our reference-food profiles. System groupings are editorial and can overlap; they do not establish health outcomes from eating a crop.
- Immune functionImmune function includes the coordinated activity of cells, tissues and biological processes involved in normal immune responses.
Foods that carry those nutrients
Sources & references (5)
- Vitamin C: Fact Sheet for Health Professionals · National Institutes of Health, Office of Dietary SupplementsVitamin C's role in collagen synthesis, physiological antioxidant activity and immune function.Source details in the Atlas: Vitamin C: Fact Sheet for Health Professionalshttps://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
- Vitamin A and Carotenoids: Fact Sheet for Health Professionals · National Institutes of Health, Office of Dietary SupplementsVitamin A's role in vision, immune function and cellular differentiation; provitamin-A vs non-provitamin-A carotenoids.Source details in the Atlas: Vitamin A and Carotenoids: Fact Sheet for Health Professionalshttps://ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/
- Vitamin C: Medical Encyclopedia · National Library of Medicine, MedlinePlusVitamin C, collagen and the growth and repair of skin, tendons, ligaments and blood vessels.Source details in the Atlas: Vitamin C: Medical Encyclopediahttps://medlineplus.gov/ency/article/002404.htm
- Vitamin A: Medical Encyclopedia · National Library of Medicine, MedlinePlusVitamin A helps form and maintain teeth, skeletal and soft tissue, mucous membranes and skin.Source details in the Atlas: Vitamin A: Medical EncyclopediaFunction section: "Vitamin A helps form and maintain healthy teeth, skeletal and soft tissue, mucus membranes, and skin." Reviewed 1/21/2025.https://medlineplus.gov/ency/article/002400.htm
- Dietary Supplements for Immune Function and Infectious Diseases · National Institutes of Health, Office of Dietary SupplementsVitamin A and vitamin C roles in tissue barriers and immune-cell function; distinct from evidence that supplements prevent or treat infections.Source details in the Atlas: Dietary Supplements for Immune Function and Infectious DiseasesTeaching locators: Vitamins and minerals sections, Vitamin A and Vitamin C introductions.https://ods.od.nih.gov/factsheets/ImmuneFunction-HealthProfessional/