Boost Your Immune System Naturally With These Four Simple Vitamins (Good News for Those 50+)

Older adults, in particular, have valid reasons to be concerned about boosting their immune system health. Age-related decline in immunity can only be addressed by taking pro-active measures.

One of those measures is to address basic nutrition for the best immune support. Scientific research has established beyond doubt that nutritional deficiency or inadequacy has the ability to impair immune functions.

This article will discuss the role four common vitamins play in immune health — and the reasons older adults should consider supplementation with these inexpensive natural nutrients.


Vitamin A — The Anti-Inflammation Vitamin That Boosts Immune System Function

You’ve probably heard about Vitamin A in terms of its importance in vision, particularly night vision.

But odds are, you didn’t know that Vitamin A is also called an anti-inflammation vitamin due to its critical role in enhancing the function of your immune system.

Vitamin A performs important functions in both innate and adaptive immunity.

Innate immunity is considered your body’s first line of defense. It involves natural barriers to infection, including the skin and mucosal cells in the eye, respiratory tract, and other systems. Vitamin A helps maintain the structural and functional integrity of these cells.

Mucus-secreting cells don’t sound pleasant, but they do good work. They provide a mechanical barrier against pathogens. For example, mucosal cells in the respiratory tract help trap small infective particles before they can work their way into your lungs and lead to health issues.

Vitamin A is also critical for adaptive immunity. While adaptive immunity takes longer to respond, it is more specific to the pathogen in question and has a more long-lasting response.

Sufficient Vitamin A is necessary for proper function of the T and B lymphocytes involved in adaptive immunity. It helps the body respond with antibodies in response to specific antigens. A Vitamin A deficiency also causes a decrease in both the number and killing activity of natural killer (NK) cells and other cells that defend against pathogens.

While severe deficiency of this vitamin is more common in developing countries, research shows that even a subclinical deficiency of Vitamin A can increase the risk of infection.

At the beginning of this discussion, you learned that Vitamin A is an anti-inflammation vitamin. Inflammation is a necessary part of immune response and is the body’s way of signaling the immune system to heal injured tissue and defend the body from foreign invaders.

Unfortunately, many people suffer from chronically high levels of inflammation because their immune system goes into overdrive and attacks healthy tissue. Vitamin A helps tamp down excessive inflammation. Studies indicate that being deficient in this all-important vitamin may not only cause inflammation, but can also aggravate existing inflammation.

This all makes Vitamin A an excellent nutrient to help support the immune system, particularly as you grow older.


Vitamin C — The Antioxidant Vitamin That Preserves Aging Immune Functions

Vitamin C is an essential nutrient that humans are unable to synthesize internally because we lack a certain enzyme.

You probably remember learning about ancient sailors on long sea voyages coming down with the potentially fatal disease called scurvy when they ran out of limes, a citrus fruit that provides Vitamin C. Scurvy causes spontaneous bleeding, anemia, ulcerations, fatigue, and other issues.

While scurvy is no longer common in modern society, a deficiency of Vitamin C is still the 4th leading nutrient deficiency in the U.S. Many people are remain at risk for basic Vitamin C deficiency, including:

  • Older adults who eat a less varied diet or anyone who eats poorly
  • Those facing excessive psychological or physical stress
  • People who smoke or drink alcohol excessively
  • Those in a lower income group who don’t get enough food with high Vitamin C levels
  • Those with medical issues affecting the body’s ability to absorb food, such as ulcerative colitis and Crohn’s disease

Vitamin C supports the function of both the innate and adaptive immune systems, similar to Vitamin A. As a powerful antioxidant, Vitamin C stimulates the production and function of white blood cells that defend against pathogens. Neutrophils, a type of white blood cell that attacks viruses and bacteria, appear to be particularly stimulated by Vitamin C.

In addition to stimulating immunity, Vitamin C also helps regulate excessive immune activity by interfering with the production of inflammatory chemicals.  This is why Vitamin C deficiency leads to impaired immunity, higher risk of infection, and problems in wound healing.

Emerging evidence suggests Vitamin C supplementation may help preserve immune function and increase resistance to infections as we grow older. Several studies have shown that Vitamin C supplements raise antibody levels.

A large analysis of placebo-controlled clinical trials found that Vitamin C supplementation reduced the duration of colds. In addition, that same analysis found that Vitamin C supplements reduced the incidence of colds by half in people undergoing extreme physical exertion, such as marathon runners.


Vitamin E — Another Antioxidant Vitamin That Improves Resistance to Infection, Particularly in Older Adults

Vitamin E is a fat-soluble antioxidant vitamin present in the membrane of all body cells. Immune cells contain especially high levels of Vitamin E, which help protect them from damage.

Adequate Vitamin E levels are critical for efficient immune function support. In fact, many animal studies have demonstrated that Vitamin E deficiency can trigger suppression of the immune system.

Inadequate levels of Vitamin E are known to impair both humoral and cellular immunity, which comprise the adaptive immune system.

Humoral immunity is known as antibody-mediated immunity. Antibodies bind to pathogens and neutralize their damage by preventing bacterial toxins from entering cells.

Cellular immunity is a type of immune response produced by the direct action of immune cells rather than antibodies. It occurs inside infected cells and is mediated by activated T lymphocytes. Helper T cells release cytokines, microscopic protein molecules that help activated T cells bind to and destroy infected cells.

Clinical evidence indicates Vitamin E supplements can improve resistance to infection, especially in older adults.

In a study of elderly men and women reported in the journal Free Radical Research, supplementation with 200 mg per day of Vitamin E significantly enhanced specific immune parameters. These included the function of immune cells such as neutrophils, T and B lymphocytes, and NK or Natural Killer cells, even bringing their values close to those of younger healthy adults.

Increased Vitamin E intake not only helps restore the decline in T-cell function associated with aging, but also helps regulate inflammation.


Vitamin D — The “Sunshine Vitamin” With Immune Function Support Benefits

Vitamin D, another fat-soluble vitamin, is quite unique. That’s because the human body can create it in the skin when exposed to sunlight. It’s not only a nutrient we eat, but also a hormone we create in our bodies.

Vitamin D helps your body absorb calcium, which is a primary building block of bone. This vitamin is crucial to nervous, muscle, and immune system health. Insufficient Vitamin D has now also been linked to many age-related health  disorders affecting multiple organ systems.

When it comes to immunity, Vitamin D plays a vital role in regulating both innate and adaptive immune responses. By stimulating innate immune responses, Vitamin D has been shown to enhance the elimination of invading bacteria, viruses, and fungi.

Many cross-sectional studies have linked lower levels of Vitamin D with increased infections. In particular, epidemiologists have linked Vitamin D deficiency to increased risk for respiratory tract infections.

You can become deficient in this vitamin for a variety of reasons:

  • Older adults don’t make Vitamin D as effectively as younger people
  • Obesity (the body fat of obese people binds with the vitamin and prevents it from getting into the blood)
  • Failure to get enough Vitamin D in the diet
  • An inability to absorb or convert the vitamin due to certain health problems
  • Spending too much time indoors or living in a climate with less sunlight
  • Certain medications interfere with the body’s ability to convert or absorb the vitamin
  • Those with dark skin have a decreased ability to produce Vitamin D from sunlight

You may want to ask your doctor to run a simple blood test that measures your Vitamin D levels. Fortunately, you can get Vitamin D in three ways:

  • Through your skin
  • From diet
  • From supplements

Because too much sun exposure can lead to skin aging and skin cancer, and because it is not found in many foods, people often decide to get Vitamin D from supplements.


Vitamin-Containing Foods Support Immune System Health — But are They Enough?

It’s important to eat plenty of foods containing these all-important vitamins — foods that can help boost the immune system naturally.

For example:

  • The best food sources of Vitamin A include eggs, cod liver oil, dark green leafy vegetables, and orange and yellow fruits and vegetables.
  • Vitamin C food sources include citrus fruits such as oranges and tangerines, spinach, kale, and broccoli.
  • Foods rich in Vitamin E include seeds, nuts, and spinach.
  • Very food foods in nature contain Vitamin D. Fatty fish such as salmon and tuna and fish liver oils are among the best sources for Vitamin D.

Unfortunately, many people are vulnerable to nutrient deficiency and in need of immune support. Older adults and those with health issues are particularly at risk. That’s why many health experts recommend supplementing with these inexpensive nutrients that are good for immune health.

As confirmed by a 2018 analysis reported in the medical journal Frontiers in Immunology: “Growing evidence suggests that for certain nutrients, increased intake above currently recommended levels may help optimize immune functions including improving defense function and thus resistance to infection.”



In this article, you’ve seen how four common vitamins impact immune health — and how a deficiency in Vitamins A, C, E, and D can diminish immune function with aging. Eating a good diet and supplementing with these inexpensive but critical vitamins is a great step to take to boost the immune system naturally.


Note: This article does not constitute medical advice. Any action should be taken only after consulting with your physician.


Sources for This Article Include:

Huang Z, Liu Y, Qi G, Brand D, Zheng SG. Role of Vitamin A in the Immune System. J Clin Med. 2018;7(9):258. Published 2018 Sep 6. doi:10.3390/jcm7090258

Reifen R. Vitamin A as an anti-inflammatory agent. Proc Nutr Soc. 2002;61(3):397-400. doi:10.1079/PNS2002172

Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017;9(11):1211. Published 2017 Nov 3. doi:10.3390/nu9111211

Oregon State University Linus Pauling Institute. Micronutrient Information Center.

Wu D, Lewis ED, Pae M, Meydani SN. Nutritional Modulation of Immune Function: Analysis of Evidence, Mechanisms, and Clinical Relevance. Front Immunol. 2019;9:3160. Published 2019 Jan 15. doi:10.3389/fimmu.2018.03160

De la Fuente M, Hernanz A, Guayerbas N, Victor VM, Arnalich F. Vitamin E ingestion improves several immune functions in elderly men and women. Free Radic Res. 2008;42(3):272-280. doi:10.1080/10715760801898838

National Institutes of Health Medline Plus.

Holick MF. Vitamin D: important for prevention of osteoporosis, cardiovascular heart disease, type 1 diabetes, autoimmune diseases, and some cancers. South Med J. 2005;98(10):1024-1027. doi:10.1097/01.SMJ.0000140865.32054.DB

Aranow C. Vitamin D and the immune system. J Investig Med. 2011;59(6):881-886. doi:10.2310/JIM.0b013e31821b8755

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>