--- title: Immunomodulatory Effects of Vitamins D, E, and C description: Vitamins D, E, and C each support distinct aspects of immune function, from T cell activity to antioxidant status and epithelial barrier integrity. image: https://www.casi.org/hubfs/casi/featured/adobestock_225936367.jpeg --- An **educational publication of Designs for Health** [For Practitioners →](https://www.designsforhealth.com) [![casilogoresize2-2](https://www.casi.org/hubfs/casilogoresize2-2.png)](https://www.casi.org/) [Home](https://www.casi.org/) [Science Update](https://www.casi.org/articles/tag/science-update) [Research & Education](https://www.casi.org/articles/tag/research-education) [Archive](https://www.casi.org/articles/all) Search articles Search Research & Education # Immunomodulatory Effects of Vitamins D, E, and C DM Danielle C. Male, MS, CNS, LDN Dec 01, 2022 ![Immunomodulatory Effects of Vitamins D, E, and C](https://www.casi.org/hs-fs/hubfs/casi/featured/adobestock_225936367.jpeg?width=960) Every stage of a healthy immune system relies on specific vitamins, including vitamins D, E, and C. The immune system is a complex array of physical and biochemical barriers, specialized immune cells, and antibodies to target potential pathogens. It is suggested that individuals with [inadequate dietary intake](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) or undergoing [infection, stress, or toxin exposure](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) may require more immune-supportive vitamins than the recommended dietary intake, as [even marginal deficiencies may negatively impact immune function](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/).  Vitamin C is a well-known immune-supportive vitamin. Not only does vitamin C promote [innate and adaptive immune functions](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/), but it also serves as a potent [antioxidant](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/). Vitamin C regenerates other critical antioxidants to their active state, including glutathione and vitamin E. It promotes [white blood cell](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) proliferation, function, and movement. Among [many roles](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/), it can support antimicrobial properties, increase serum complement proteins, attenuate histamine levels, and modulate proper cytokine production. Human studies in adults, children, and athletes observe that vitamin C supplementation may help support a [healthy immune system](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) and promote a [healthy microbial environment](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/).   Vitamin D is integral for [innate](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) physical barriers to immune health. It supports a healthy gut barrier by increasing [tight junction protein expression](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) and promotes a [healthy gut microbial environment](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/). Approximately [70% to 80% of the immune system is in the gut](https://pubmed.ncbi.nlm.nih.gov/33803407/). Vitamin D promotes [lung, kidney, and eye epithelial barrier function](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) when exposed to potential pathogens. It is also involved in reducing the expression of [pro-inflammatory](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) cytokines and increasing the expression of [anti-inflammatory](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) cytokines. It plays an integral role in the proper differentiation and function of [monocytes to macrophages](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/).   [Five meta-analyses](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) concluded that vitamin D supplementation between 300 IU per day to 3,653 IU per day in adults and children promotes respiratory tract health. Low vitamin D levels have been observed in higher disease activity and severity in autoimmune diseases such as [rheumatoid arthritis, lupus, and multiple sclerosis](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406/).   Vitamin E is a fat-soluble [antioxidant](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) that protects cell membranes from damage caused by free radicals and supports the [integrity of epithelial barriers](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/). Vitamin E [indirectly promotes T-cell function](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/) by decreasing prostaglandin E2 from macrophages and is necessary to maintain the [Th1/Th2 balance](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/).  [In vitro](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7011499/), tocotrienols (a vitamin E subtype) enhanced lymphocyte proliferation and facilitated immune responses to antigens. Studies suggest the beneficial immunomodulatory effect of tocotrienols may be [more pronounced in aging individuals](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7011499/), as seen in a [double-blind controlled trial](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7011499/) of subjects receiving 400 mg of tocotrienols per day, but further research is needed.  There is an overlap in the immunomodulatory roles of vitamins D, E, and C. For example, all three vitamins support the [differentiation, proliferation, and normal functioning of T cells](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/). Proper intake of each vitamin through diet or supplementation is required for their unique roles in supporting the immune system. 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Male, MS, CNS, LDN Clinical Application ## Clinical Considerations in Practice In clinical practice, practitioners considering the topics discussed above may also weigh nutrient form, delivery and formulation, alongside individual patient variability. ### Practitioner Formulation Example ![Immune Support Packets](https://cdn.sanity.io/images/lemtscrs/production-www/bc478c273a234343865e24cf9cb18c466866b520-2000x2000.png?w=128&h=128&fit=max&auto=format) Immune Support Packets Nutrient blend · Packets [Explore Formulations →](https://www.designsforhealth.com/products/immune-support-packets) ## Continue your research #### [Science Update A Case Report on Vitamin C Supplementation in a 67-Year-Old Male with Leukopenia Jul 21, 2026](https://www.casi.org/articles/a-case-report-on-vitamin-c-supplementation-in-a-67-year-old-male-with-leukopenia) #### [Science Update Integrative Management of Estrogen Dominance, Methylation Impairment, and Histamine Intolerance in Perimenopause: A Case Report Apr 23, 2026](https://www.casi.org/articles/integrative-management-of-estrogen-dominance-methylation-impairment-and-histamine-intolerance-in-perimenopause-a-case-report) #### [Research & Education Gut and Immune Health: A Clinical Review of Their Interconnected Systems Nov 12, 2025](https://www.casi.org/articles/gut-immune-health-interconnected-systems) #### [Research & Education The 8 Most Clinically Relevant Mushrooms to Know About in 2025 Sep 18, 2025](https://www.casi.org/articles/8-clinically-relevant-mushrooms-2025) ![casilogoresize2-2](https://www.casi.org/hubfs/casilogoresize2-2.png) An educational publication of [**Designs for Health**](https://www.designsforhealth.com). Peer-reviewed nutrition science, free for everyone. #### Sections - [Science Update](https://www.casi.org/articles/tag/science-update) - [Research & Education](https://www.casi.org/articles/tag/research-education) #### Terms & Conditions - [Privacy Notice](https://www.designsforhealth.com/privacy-notice) - [Terms of Use](https://www.designsforhealth.com/terms-of-use) CASI.org © 2026 All rights reserved Do not sell my personal information Built with care · Peer-reviewed since 1996 ```json { "@context" : "https://schema.org", "@type" : "BreadcrumbList", "itemListElement" : [ { "@type" : "ListItem", "item" : "https://www.casi.org/", "name" : "Home", "position" : 1 }, { "@type" : "ListItem", "item" : "https://www.casi.org/articles", "name" : "The CASI Library", "position" : 2 }, { "@type" : "ListItem", "name" : "Immunomodulatory Effects of Vitamins D, E, and C", "position" : 3 } ] } ``` ```json { "@context" : "https://schema.org", "@id" : "https://www.casi.org/articles/immunomodulatory-effects-of-vitamins-d-e-and-c", "@type" : "WebPage", "dateModified" : "2026-09-17" } ``` ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "Danielle C. Male, MS, CNS, LDN", "url" : "https://www.casi.org/articles/author/danielle-c-male-ms-cns-ldn" }, "datePublished" : "2022-12-01T05:00:00.000Z", "headline" : "Immunomodulatory Effects of Vitamins D, E, and C", "image" : [ "https://www.casi.org/hubfs/casi/featured/adobestock_225936367.jpeg" ], "mainEntityOfPage" : { "@id" : "https://www.casi.org/articles/immunomodulatory-effects-of-vitamins-d-e-and-c", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://www.casi.org/hubfs/casilogoresize2-2.png" }, "name" : "CASI.org" } } ```