When flu season approaches many of us wonder, What can I do to support my immune system? This is a great question because research indicates that if 20 people are exposed to the flu virus, half of them may not get sick – thanks to a robust immune system. Similarly, a properly functioning immune system helps prevent cancer, heart disease and a host of other adverse health conditions.

So back to the original question, what can I do to ensure a healthy immune system? Below are several natural, science-backed, ways to maintain optimal wellness through flu season and beyond.

1) Get your Vitamin D Levels Checked

You are 10 times more likely to get a cold or flu if you’re deficient in Vitamin D. But, supplementing with vitamin D can reduce colds and flu by 42 percent.

Low levels of Vitamin D are also associated with osteoporosis, neurological and mood disorders, cardiovascular diseases, diabetes, cancer and autoimmune diseases.

Blood levels of Vitamin D are considered “normal” at 30 ng/dl, but most functional medicine practitioners like to see patient levels around 50 ng/dl or even a little higher. If you have your blood levels tested in the summer and your levels are fine, consider testing again in the winter to be sure your levels don’t drop out of range in winter.

2) Stay hydrated

Every cell, tissue and organ needs water to function properly. Plus, water is needed to flush out toxins and carry immune cells throughout your body.

In the winter months when the air is cold and typically drier, it can be challenging to stay hydrated, increasing your risk of getting sick. Then, if you do catch a bug, losing water due to excessive sweating or the ill-effects of a stomach bug can lead to further dehydration. Dehydration itself can cause headaches, dizziness and exacerbates a fever. Drinking fluids will help lower a fever and alleviate headaches associated with dehydration.

The best choices for hydration include plain water, (decaffeinated) herbal teas and clear broths. Avoid 100% fruit juices (apple, grape, pineapple, etc.) or any sweetened beverage.

3) Wash hands and flush sinuses

Good ol’ fashioned hand washing is your first line of defense and flushing your sinuses may be the second. For hands, washing them with plain soap will do. (Avoid anti-bacterial soaps unless absolutely necessary.)  In between hand washing, try to keep your hands away from your face. 

Using a saline nasal wash keeps mucous membranes moist and keeps microbes at bay.

4) Avoid sugar

Avoid sugar in all it’s forms (corn syrup, brown sugar, fructose, maltose) as well as simple carbohydrates (white flour, rice, potatoes) as they suppress your immune system and are pro-inflammatory. If you do include simple carbohydrates in your diet on occasion, limit them to small amount with a meal containing healthy fats, fiber or protein to blunt their affect on your blood sugar levels. Drinking alcohol in moderation is also helpful.

5) Get adequate amounts of protein

The amino acids in protein are the building blocks of cells, tissues and organs throughout the body including your immune system, detoxification systems and gut health.

6) Include antimicrobial spices and foods in your diet

Top picks are: oregano, turmeric, thyme, ginger, garlic, onions, and Skitake mushrooms. These are great additions to soups and stews, dips and sauces.

7) Eat the rainbow!

Brightly colored fruits and vegetables contain phytonutrients and antioxidants like Vitamin C and A that support your immune system. Top immune boosting veggies include dark leafy greens, cruciferous vegetables (cauliflower, brussels sprouts and broccoli) peppers, sweet potatoes and squashes. Shoot for three to four serving of fruit and four or more servings of vegetables each day.

8) Get your rest and manage stress

Getting adequate rest (7-8 hours each night) and lowering stress are a must for optimal immune function. Yet many of us find these two goals among the most difficult to achieve—especially during the busy holiday season. To understand why prioritizing on sleep is so important, read this post. The breathing technique (described in this post) is a simple and effective way to reduce stress that can be done just about anywhere—and no one will even know you’re doing it.

9) Keep moving!

Getting regular moderate exercise helps boost your immune system. However, working out when you’re battling the flu (fever, chills and sweats) is not the time to hit the gym as doing so can lower your immune defenses.

To maintain a healthy immune system, shoot for 30-45 minutes of moderate exercise on most days.

10) Avoid toxins

Limit exposure to: cigarette smoke (including second and third-hand smoke), artificial ingredients and chemicals in foods, household and personal care products.

11) Consider taking supplements

Eating a healthy diet is paramount, but it may not always be enough to stay in peak health. Below are supplements that may help adults support their immune system.

(Important Notice: If you are have been diagnosed with a medical condition, are taking prescription drugs and/or under the care of a physician, do not take any supplements without the advice and consent of your doctor or pharmacist. While most supplements contain natural substances, they may not be appropriate for everyone, especially pregnant women and children. Some supplements can also interact with medications and change how they work.)

Multivitamin/Mineral – A good quality multivitamin/mineral may already be part of your wellness plan, but if not, consider adding one. Why you ask? Studies show that most of us are not getting adequate amounts of important nutrients from our diet alone and a multivitamin/mineral can help fill those nutritional gaps.

Since adequate nutrition is the foundation of good health and a robust immune system, taking a multivitamin/mineral provides an extra ounce of prevention.

Multivitamin formulations have become more varied and personalized based on a variety of factors including age, gender, health status and genetic traits. They are also available with or without trace minerals and minerals needed in higher amounts. Your functionally-trained physician can help recommend a formula that is right for you.

Vitamin D3 – While our bodies make Vitamin D from sunlight, many of us are spending more time indoors and wearing sunscreen when we do venture outdoors. So maintaining optimal levels of Vitamin D without supplementation can be difficult – especially in the winter months.

The dose and formula that is right for you is best determined by your doctor via regular testing as your body’s needs can change over time due to age and illness.

When purchasing Vitamin D supplements, be sure it’s the active form of Vitamin D called D3. A typical maintenance dose is 2,000 IUs per day in sunny months/climates and 5,000 IUs in winter.

Vitamin C – The role of Vitamin C in immune health is well known, and for good reason. Studies show that regular use of Vitamin C shortens the duration of the common cold.

Vitamin C supplements are available as ascorbic acid (or L-ascorbic acid) and buffered Vitamin C (for those with sensitive stomachs). Both are generally taken with food.

Adults can take Vitamin C with meals or snacks throughout the day in divided doses of 500 to 1,000 mg each for a maximum daily dose of about 3,000-4,000 mg/day total. The upper tolerable intake depends on the individual. Too much Vitamin C (typically more than 2,000 per dose or 8,000 mg per day) can cause nausea or diarrhea.

Zinc Citrate – In studies, zinc has been shown to reduce the duration of cold symptoms. When symptoms of a cold appear, the typical dose is 30 mg per day until symptoms resolve, but not longer than two weeks. Taking more than 40 mg/day for adults is not recommended for long term use as it may create copper deficiency. (Zinc and Copper balance one another, too much of one depletes the other.)

Probiotics – Probiotics can help ensure a healthy balance of gut bacteria and the integrity of the gut lining which supports overall gut health and immune function.

With today’s advanced gut testing, functional medicine physicians can assess your gut health and recommend specific probiotic strains to take or avoid. In the absence of testing, most experts recommend that adults interested in maintaining overall gut health take a multi-strain probiotic containing five or more different strains.

There are many great formulas on the market including ones that are free of common allergens including dairy, wheat and soy.

Cod Liver Oil – The elixir of our grandparents really does support overall health and immune function due to its combination of Vitamin A and D along with health fats. Thankfully today’s formulas are available in capsule form.

Anti-Viral/Bacterial Herbs – Many herbs have been shown to have antimicrobial properties or immune modulating effects. They include green tea extract, echinacea, elderberry, goldenseal, astragalus and certain mushrooms. Echinacea, like zinc, is not recommended for long-term use. It is taken just before cold and flu season for about 8-10 weeks. Whereas green tea can be enjoyed year-round for immune benefits.

Mushroom Extract - Among the mushrooms highly regarded for favorable affects on our immune system are Shitake, Cordyceps, Maitake, Enoki, Reishi, Lion’s Mane and Turkey Tail, but there are many others. Some of these are culinary mushrooms that can be found in supermarkets, others are available in supplement form.

Stock up on Immune Support

With hundreds of brands and thousands of options to choose from, finding the highest quality, effective supplements can be daunting. So I’ve pulled together some of the immune support formulas that my Functional Medicine physicians trusted and recommended to me and put them all in ONE PLACE in our dispensary. Some of the formulas are professional brands that are not widely available or are only sold through physicians and health/wellness providers.

When you visit our Fullscript dispensary, you will need to create an account/log in and click on “Catalog” in the navigation. Then scroll down to the “Practitioner categories” section and click on “Immune Support.” You will find most of the supplements listed in this post, including: Vitamin D, Vitamin C, Zinc, Multivitamin formulas for Men, Women and those with MTHFR SNPs, Immune Support formulas containing herbs, vitamins and mushrooms, mushroom only formulas and probiotics.

Feel free to browse through the entire product catalog and search by health condition, brand and product name.