The role of vitamin C, vitamin D, and zinc in supporting your immune system

Keeping your immune system functional is essential for staying healthy and fighting off illness.ⁱ There are some nutrients that can help to keep the immune system healthy. Of them, these three nutrients vitamin C, vitamin D and Zinc, can play a key role in supporting healthy immune system function.ⁱⁱ Let’s explore how each of these nutrients helps keep your immune system in shape.

But first, a quick overview of the immune system. The immune system is a complex network of organs, cells and chemicals that work hard to protect us from potentially harmful substances and germs that can make us ill.ⁱⁱ It can be divided into epithelial barriers (such as our skin and mucous membranes that form physical protective barriers), cellular defence (these are your immune system cells that directly attack and destroy germs), and substances such as antibodies (which are produced by certain immune cells when they detect harmful substancesiii), constituting the three main lines of immune defence.ⁱⁱ

Vitamin C: The Immune System’s Friend

Vitamin C, also known as ascorbic acid, is an antioxidant that helps reduce free radical damage to body cells.

It supports the immune system to fight illness all year round. It can also reduce the duration and severity of common cold symptoms.ⁱⁱ

Vitamin C is also involved in wound healing^x and in the production of collagen, a protein that helps maintain the skin’s barrier function, providing an extra layer of defence against germs.ⁱⁱ

As it is a water-soluble vitamin, it is excreted easily and not stored in the body.^iv,Our bodies also cannot manufacture vitamin C and so it needs to be obtained regularly through the diet.^ix If the dietary intake is not enough, supplementation can be an option.

Vitamin D: The Sunshine Vitamin

Vitamin D, often called the “sunshine vitamin,” is unique because your body can produce it when your skin is exposed to sunlight.^v It can also be obtained from certain foods and supplement. Foods that are high in vitamin D include, mushrooms, egg yolks and certain types of fish.

Vitamin D supports immune system health so it is important that we have adequate levels for this important function to occur. Despite living in what is generally considered a sunny country, it is possible to have low levels.^vi Try to get a few minutes of sunshine a day as a sun safe exposure, and if you need support to maintain vitamin D levels in the body supplementation may be of benefit.

Zinc: The Essential Mineral

Zinc is a trace mineral that is required for healthy immune system function. It is essential for the activity of over 300 enzymes within the body, some which have an effect on the immune system.^vii

It supports healthy skin and connective tissue formation, which is important for maintaining the skin’s barrier function.^x

Ensuring adequate levels of these 3 key nutrients through a varied diet, sunlight exposure, and top up with supplements such as Cenovis Chewable Triple Action Vit C, D & Zinc, can help support healthy immune system function.

References

[i] Healthdirect. Immune System. 2023 https://www.healthdirect.gov.au/immune-system (accessed 17/3/25)

[ii] Maggini S, et.al. (2017). Vitamins C, D and Zinc: Synergistic Roles in Immune Function and Infections. Vitam Miner 6: 167

[iii] Cleveland Clinic. Antibodies. 2022 https://my.clevelandclinic.org/health/body/22971-antibodies (accessed 17/3/25)

[iv] NIH. Vitamin C. 2021 https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/ (accessed 17/3/25)

[v] Nowson CA et al. Vitamin D and health in adults in Australia and New Zealand: a position statement. Med J Aust 2012; 196 (11): 686–87.

[vi] Australian Health Survey: Biomedical Results for Nutrients, 2011–12.

[vii] Rink L & Gabriel P, Zinc and the Immune system. Proceedings of the Nutrition Society (2000), 59, 541–552 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/23B26245CF0F773E5F1AA19E9800B82B/S0029665100000781a.pdf/zinc-and-the-immune-system.pdf

[ix]Better Health Channel. Vitamins and Minerals 2024.https://www.betterhealth.vic.gov.au/health/healthyliving/Vitamins-and-minerals

[x] Health Canada. Multi-Vitamin/ Mineral Supplements Monograph. 2023 https://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq?atid=multi_vitmin_suppl&lang=eng