As cold and flu season arrives, one of the best ways to protect yourself and your family is by strengthening immune resilience. This means giving your body the nutrients it needs to mount strong defenses and recover quickly if you do get sick.
Key Vitamins and Nutrients That Support Immune Health:
Vitamin D supports barrier defenses and helps regulate immune signaling, making it a key player in fighting viruses.
Sources: Salmon, sardines, cod liver oil, sunshine.
Vitamin C acts as an antioxidant, protects skin and mucous membranes, and boosts the ability of white blood cells to fight germs.
Sources: Red bell peppers, strawberries, oranges, broccoli, Brussels sprouts, guava, kiwi, parsley, kale.
Vitamins A and E keep protective barriers strong and help manage inflammation. Sources: Organ meats, cod liver oil, eggs, pumpkin, spinach, butternut squash, sweet potato, carrots, collards, turnip greens, winter squash, sunflower seeds, almonds, hazelnuts, peanuts, olive oil.
B vitamins (B6, B12, folate) are needed to produce antibodies and grow new immune cells. Sources: Chickpeas, beef liver, potatoes, salmon, turkey, bananas, clams, crab, beef, eggs, lentils, pinto beans, arugula, kale, broccoli, avocado.
Zinc keeps cell membranes strong, calms inflammation, and supports antibody production. Sources: Oysters, beans, pumpkin seeds, cashews, beef.
Selenium helps T cells develop and allows them to destroy infected cells.
Sources: Brazil nuts, oysters, clams, halibut, sardines, sunflower seeds.
Iron and magnesium help immune cells multiply and make antibodies.
Iron sources: Organ meats, beef, oysters, clams, soybeans, white beans, lentils.
Magnesium sources: Pumpkin seeds, Brazil nuts, almonds, spinach, chard, cashews, peanuts, black beans, hazelnuts, avocado, brown rice.
Omega-3 fatty acids regulate inflammation and make immune cells work more efficiently. Sources: Salmon, sardines, anchovies, trout, flaxseed oil, chia seeds, flaxseeds, walnuts, hemp seeds.
Food First, Supplements When Needed
The best way to get these nutrients is through a balanced, Mediterranean-style diet rich in colorful fruits, vegetables, legumes, nuts, whole grains, lean proteins, and healthy fats. In some cases, targeted supplementation of missing nutrients can be helpful, especially when deficiencies are present. Always aim to stay within safe limits and personalize your approach or consider working with a provider to assess your nutrient status through testing.
Lifestyle Matters Too
- Eat a nutrient-dense diet.
- Get outside in the sun when possible.
- Ask your provider to check your Vitamin D status twice per year. I usually recommend clients check their status in the height of the winter and one month into summer.
- Get regular movement.
- Prioritize quality sleep and stress management.
- Support gut health with fiber, prebiotics, and probiotics.
Test Don't Guess
Even with a nutrient-rich diet, it’s common to have hidden deficiencies that affect how you feel and function. Factors like stress, gut health, genetics, medications, and absorption efficiency all influence how well your body uses the nutrients you eat. This is why testing, not guessing, can make such a difference.
U.S. research shows that many adults are not meeting their daily nutrient needs. About 95% fall short on vitamin D, 84% on vitamin E, 46% on vitamin C, 45% on vitamin A, and 15% on zinc. Deficiencies in B vitamins are also common, vitamin B6 is low in roughly 16–23% of adults, and vitamin B12 in 2–4%. Thanks to food fortification, true folate deficiency is now rare, though many still have suboptimal levels. Iron deficiency affects up to one in five women of reproductive age. Omega-3 fatty acid intake remains below recommended levels for most Americans, even though it’s not routinely tested.
Some nutrients can be checked through standard bloodwork with your primary care provider. If you go this route, it’s worth confirming insurance coverage beforehand to avoid unexpected costs. Ask your provider to include the following markers, as they can offer valuable insights into your nutrient status and overall health.
Ask your provider to check:
- Ferritin, Iron, TIBC, Transferring
- Vitamin D, 25-OH
- B12
- Folate
- Magnesium
- Homocysteine
- MMA
- CBC w/diff
For more advanced testing, I like using the Vibrant Micronutrient Panel in practice. The Micronutrient Panel is a comprehensive blood test that assesses both intracellular (within the cell) and extracellular or serum (circulating in the blood) levels of essential vitamins, minerals, antioxidants, and amino acids. By evaluating nutrients at both the cellular and serum levels, this panel provides a more complete picture of nutrient status, revealing not only what is present in the bloodstream but also what is being effectively utilized by the body. This can give us a snapshot of the last several months of intake. It offers precise insights into nutrient absorption, metabolism, and potential deficiencies, guiding personalized dietary and supplementation strategies to optimize overall health and metabolic function.
In my practice, this test often confirms what we suspect clinically while revealing deeper layers. By identifying these hidden imbalances, we can create a truly individualized plan that helps you restore optimal energy, mood, and immune resilience.
Over the years, I’ve worked with adults, teens and many college students dealing with fatigue, frequent infections or illness, and even mononucleosis. With nutrition, lifestyle shifts, and targeted supplements, they regained their energy and resilience. The right foundation makes all the difference.
If you or someone in your family could benefit from a personalized approach to building immune resilience, I invite you to reach out and book a complementary discovery call. Together, we can create a plan tailored to your needs and help you move into the season with more confidence, energy, and health.
Functional Nutritionist