The Ultimate Immune Toolkit: 7 Essential Nutrients for Year-Round Health

Ensure your immune system is functioning optimally with these 7 essential nutrients.

The human immune system is truly amazing. It functions as your 24/7 highly sophisticated security team, constantly defending your body against foreign organisms—from common bacteria and viruses to fungi and toxins.

When your immune system runs smoothly, you barely notice it. It’s only when it’s weakened or overwhelmed that you become susceptible to illness. So, how can you ensure this vital defense system is functioning optimally?

While there is no single "magic bullet" for immunity, a significant body of scientific research confirms the immunoprotective properties of certain nutrients. Furthermore, even those who maintain a healthy, balanced diet can struggle with absorption and bioavailability, meaning many essential vitamins and minerals may not be properly utilized by the body.

Below are 7 key nutrients that can help boost and balance your immune system, during flu season and beyond.

1. B-Complex: The Building Blocks of Immune Response

As the building blocks of a healthy body, the eight B vitamins are critical for optimal energy, cell functioning, and proper nerve function. For the immune system, they are absolutely pivotal, assisting in both the innate (first line of defense) and adaptive (long-term memory) immune responses.

A 2020 study highlighted that B-complex vitamins help reduce pro-inflammatory cytokine levels, maintain endothelial integrity, and may reduce the length of hospital stays associated with severe infections.

Primary food sources: Whole grains, eggs, meat, poultry, legumes, nuts, salmon, nutritional yeast.

There is a need to highlight the importance of vitamin B because it plays a pivotal role in cell functioning, energy metabolism, and proper immune function. - Source

2. Vitamin D: The Immune System’s Critical Regulator

Vitamin D is more than a bone health hero; it is a powerful hormone regulator for the immune system. A deficiency in Vitamin D is strongly associated with an increased susceptibility to various infections, autoimmune diseases, and depression.

Vitamin D’s primary immune role is helping your body produce antimicrobial peptides—indispensable components of the innate immune system. These peptides are your body's first line of defense against attacks from foreign invaders, including drug-resistant microbes. Since few foods naturally contain enough Vitamin D and adequate sun exposure can be difficult to achieve year-round, deficiency is a worldwide public health problem. Aim for getting outside during peak sunlight each day for at least 15 minutes (yes, even on cloudy days!) for a daily dose of vitamin D.

Primary food sources: Fatty fish (salmon, tuna), fish liver oils, fortified milk and juices, and egg yolks.

Vitamin D is important to the function of the immune system and vitamin D supplements have previously been shown to lower the risk of viral respiratory tract infections. - David Meltzer, Chief of Hospital Medicine at University of Chicago Medicine

3. Zinc: Essential for T-Cell Development

Zinc is an essential mineral involved in hundreds of cellular processes, including DNA formation, wound healing, and protein synthesis. Zinc is also required for the development and function of immune cells.

Specifically, it is vital for the maturation of T-cells (a type of white blood cell that attacks infected cells) and natural killer cells. Even a mild deficiency can impair immune function, making supplementation especially relevant, since the mineral's bioavailability through plant-based food sources is often highly variable.

Primary food sources: Oysters, red meat, beans, nuts (cashews, almonds), and dairy products.

4. Vitamin C: The Front-Line Antioxidant

Vitamin C is a potent antioxidant and a required cofactor for numerous enzyme reactions. Studies show that a Vitamin C deficiency results in impaired immunity and higher susceptibility to infections.

It supports the function of various immune cells, particularly phagocytes—cells that essentially "eat" and neutralize pathogens. Furthermore, as an antioxidant, Vitamin C protects immune cells from damage caused by the high levels of oxidative stress generated during the fight against an infection.

Primary food sources: Citrus fruits, bell peppers, strawberries, broccoli, and kiwi.

5. Glutathione: The Master Detoxifier

Naturally produced in the liver, glutathione is often called the body’s "master antioxidant." It helps neutralize free radicals and reduce the oxidative stress that can damage cells and weaken the immune system.

The immune system works best when its lymphoid cells have a balanced level of glutathione; depletion is often linked to viral infections and their associated disease progression. Because dietary glutathione is very sensitive to cooking and storage and is poorly absorbed by the human body, supplementation is crucial for optimizing levels.

Primary food sources: Onion, garlic, spinach, cauliflower, asparagus, walnuts, and avocado.

6. Vitamin B12: Fuel for New Cell Production

Like the other B vitamins, B12 (cobalamin) is required for the body’s ability to create new immune cells and initiate a rapid immune response. In clinical studies, Vitamin B12 has been shown to offer immunoprotective effects, especially in individuals with neurological or immunological disorders.

Beyond immunity, B12 is essential for battling fatigue, chronic pain, anemia, and brain fog, making it a foundational nutrient for overall wellness.

Primary food sources: Shellfish, meat, fish, eggs, and fortified nutritional yeast.

7. Lysine: The Rapid Recovery Amino Acid

Lysine is an essential amino acid that plays a crucial role in the production of enzymes, antibodies, and hormones that support the immune system.

It is also a key component of tissue growth and repair, helping the body recover from damage. Additionally, Lysine aids the absorption of critical minerals like calcium, iron, and zinc—the last of which, as noted, is vital for immune response.

Primary food sources: Meat, cheese (especially Parmesan), eggs, soy products, and fish.

Bridging the Gap: Why Targeted Supplementation Matters

Clearly, supporting your immune system is a multi-nutrient effort. However, simply relying on diet is often insufficient due to variable food bioavailability, nutrient depletion in modern soil, and personal digestive and absorption issues.

This is where targeted, high-quality supplementation and therapeutic delivery methods become a powerful tool.

As a Registered Nurse and Health Coach, I understand the challenges clients face in achieving optimal nutrient levels. At VIVE, we make it easy to incorporate these immune essentials into your wellness routine by offering delivery methods that bypass common absorption issues. Intravenous and intramuscular delivery ensure 100% absorption into your bloodstream, delivering powerful doses where they are needed most, without relying on (or upsetting) your digestive system.

I also have recommendations for all of these nutrients as high-quality oral supplements for daily maintenance between drips and shots, along with a range of immune-supportive herbal formulas. Check out my FullScript online apothecary for more details (p.s. Ask me how you can get a discount on oral supplements!).

xo, Emily

Looking for personalized health and wellness guidance? Visit Jensen Wellness to learn more about my 1:1 health coaching and other services.