5 Simple Ways to Support Your Immune System

By Cassie Prewitt, FNP-C, Clinic 5C Functional Medicine

Your immune system works hard every day to protect you, are YOU taking care of it too?

Whether it’s fighting off seasonal illnesses or helping your body recover, understanding the basics of immunity can help you make smarter lifestyle choices.

In this guide, we’ll break down what the immune system is and share simple, evidence-based ways to support your immune system, including diet, exercise, vitamin D, sleep, and taking probiotics, so you can stay strong and resilient year-round.

What is the Immune System?

The immune system has two primary arms: the innate immune system and the adaptive immune system.

• The innate immune system serves as our first line of defense and is the body’s immediate response to pathogens.
• The adaptive immune system takes longer to develop (usually days to weeks) but provides a highly specific response tailored to the antigens we encounter. Antibodies (critical tools our bodies use to neutralize threats) are part of the adaptive immune system.

We encounter pathogens daily, so keeping these systems strong is key to maintaining wellness and resilience.

5 Ways To Support Your Immune System

1. Diet

Adequate intake of specific micronutrients is essential for the development, maintenance, and optimal function of both innate and adaptive immune responses.

This includes vitamins A, C, D, E, B6, B12, folate, zinc, iron, selenium, copper, and omega-3 fatty acids.

Restoring any micronutrient deficiencies improves immune competence, which means your body can more effectively recognize and respond to pathogens.

2. Exercise

Regular, moderate-intensity exercise is a powerful way to support your immune system and reduce inflammation.

When you exercise, your body experiences a temporary rise in white blood cells (a process called transient leukocytosis), helping immune cells circulate more effectively.

Physical activity also encourages the production of anti-inflammatory molecules called cytokines and stimulates the release of myokines.

Myokines are proteins from muscles that help regulate immune function and keep inflammation in check.

Studies consistently show that people who engage in moderate exercise like brisk walking, cycling, or swimming on a regular basis have fewer upper respiratory infections compared to those who are sedentary.

‍Simply put, keeping your body active helps your immune system stay sharp and ready to defend you.

3. Vitamin D

Maintaining healthy vitamin D levels (ideally above 60 ng/mL) plays an important role in supporting your immune system.

Vitamin D helps your body’s first line of defense (the innate immune system) by boosting the production of antimicrobial peptides, which help fight off harmful microbes.

It also promotes autophagy, which is a natural process that helps immune cells called macrophages clear out infections more efficiently.

In the adaptive immune system, vitamin D reduces the production of pro-inflammatory cytokines. These are molecules that, in excess, can contribute to chronic inflammation.

By keeping inflammation in check and supporting immune cell activity, vitamin D helps your body stay strong and ready to fight infections.

If you’re unsure about your vitamin D status, come see us at Clinic 5C Functional Medicine to order a simple blood test.

We can help you understand your levels, and whether you might benefits from vitamin D supplementation.

4. Sleep

Quality sleep is essential for initiating and maintaining adaptive immune responses.

In fact, studies show that poor sleep or sleep deprivation increases systemic inflammation, alters immune cell trafficking, impairs immune cell function, reduces vaccine effectiveness, and increases susceptibility to infections.

Prioritizing good sleep is an important (and a very often overlooked) component of immune health.

5. Probiotics

Certain probiotic strains (especially Lactobacillus and Bifidobacterium) can play an important role in supporting a healthy immune system.

How do probiotics help?

• They strengthen the mucosal barrier, helping protect and maintain the integrity of the gut lining, which is a key part of your body’s defense system.
• They influence the immune response by encouraging anti-inflammatory molecules (like IL-10) and reducing pro-inflammatory molecules (such as TNF-alpha and IL-6) that can drive excess inflammation.
• They help improve gut balance by correcting dysbiosis (an unhealthy gut microbiome) and supporting a strong intestinal barrier. This is sometimes called "leaky gut" when impaired.
• They reduce harmful gut bacteria while supporting the growth of beneficial bacteria, helping maintain a healthy, balanced gut environment.

Because the gut is so closely connected to immune health, probiotics can help support both your innate immune system (your body’s immediate defense) and your adaptive immune system (which targets specific threats over time).

Key Takeaway

One of the most important concepts to remember is prevention: fueling and supporting your body appropriately to prepare it to defend against daily pathogen exposure.

We can’t avoid encountering germs, but by maintaining good nutrition, regular exercise, optimal vitamin D levels, healthy sleep patterns, and gut health, we can help ensure that our immune system is ready to respond effectively and keep us well.

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