7 Simple Ways To Boost Your Immune System This Fall

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It’s always a good idea to work on strengthening your immune system, especially since fall and winter are here, and it’s getting colder. With the flu season, plus viral variants among us, it never hurts to add a few healthy habits to your routine. This blog will go over some key points to help boost your immune system.

Your Daily Routine

Your daily habits play a significant role in your overall health. If you read my previous immunity blog, you know the basics about eating your veggies, staying hydrated, keeping active, and getting enough sleep. But here are some additional points to take into consideration to help reset your immune system naturally.

Vitamin D3

The importance of Vitamin D3 on the immune system has become more evident in recent years. When you are deficient in this nutrient, you increase your susceptibility to infection and potential autoimmunity. Traditionally, Vitamin D3 was thought to help with the absorption of calcium and promote bone health. Studies have shown that the active form of Vitamin D, 1,25-dihydroxy Vitamin D, activates immunologic actions on several parts of your innate and adaptive immune system. For example, before there were antibiotics, Vitamin D3 was unknowingly used to treat infections like tuberculosis. Tuberculosis patients were sent to facilities where they were treated with sunlight exposure, which was thought to directly kill the disease. They were also given Cod liver oil, which is a rich source of Vitamin D3. Being deficient in Vitamin D3 increases your risk of developing several immune-related disorders, such as psoriasis, rheumatoid arthritis, type 1 diabetes, tuberculosis, multiple sclerosis, respiratory infection, sepsis, and even COVID-19.

You should have your Vitamin D3 levels checked by having a routine blood test. Vitamin D3 levels are normally considered sufficient when they are above 30 ng/ml. I personally recommend that my patients be at 60-90 ng/ml to be optimal. I would consider you deficient if your levels fall below these numbers.

Luckily, there are various ways to get additional Vitamin D3:


Vitamin D3 is synthesized in the skin after exposure to UV B light, aka sunshine. The easiest way to up your D3 levels is to get outside and spend some time under the sun. The best time for sun exposure is at midday. This is when the sun is highest in the sky and when there is more UVB radiation in the spectrum, which triggers Vitamin D production in your skin. Take care to avoid sunburn; 20 minutes a day without sunscreen will help. Just note that our bodies cannot convert the UVB light very well to an active D3 that our body can use. Therefore supplementation is almost always needed. I have not had one patient optimal in Vitamin D3 levels without supplementation, even here in California. So don’t just guess you’re optimal. Test- this is not the time to be willy nilly about your Vitamin D3 protection.


Vitamin D3 is a fat-soluble Vitamin that is naturally present in a few foods and added to other fortified foods. The best sources come from the flesh of fatty fish (i.e., salmon, tuna, trout, and mackerel) and fish liver oils. Egg yolks, beef liver, and cheese contain trace amounts of Vitamin D3.


If your Vitamin D3 levels are low, consider taking a supplement. The commonly recommended daily dose of Vitamin D for individuals above the age of 5 is 600 IU (15 mcg.) Most forms sold are Vitamin D3, which is what your body naturally makes from sunlight. There is much debate on which is the best Vitamin D supplement. Remember, the retail market of supplements are not regulated (e.g., local drug stores, markets, big-box warehouse stores, health food stores, etc.). There is no regulating body requiring a check for purity, such as clearing for mold, toxins, heavy metals, dangerous fillers, or making sure what is printed on the label is actually in the bottle. I never recommend buying supplements on the internet. Read my blog article about Buyer Beware to understand how to protect your body from pirated supplements. I use only professional-grade supplements, and you can rest assured that they are clean and bioavailable for your body to absorb. I use a sublingual liquid form of Vitamin D3, but capsules can also be used. In order to get your levels up to optimal ranges, you would need at least 5000 IU daily, and many of my patients need to be on 10,000 IU daily. Remember: test, don’t guess! You can find the one that I use and personally recommend here or capsules here.

Another supplement to consider is Quercetin with Bromelain. Quercetin is a natural flavonoid molecule that is found in many fruits and vegetables. What sets Quercetin apart is that it donates electrons to free radicals, neutralizing them. This helps prevent inflammation and histamine development in the body. Read this article for Quercetin and Bromelain to learn why they are paired, and how they give the immune system a huge boost.

Quercetin is a safe, natural anti-oxidant and anti-inflammatory polyphenolic compound that is naturally found in a few sources like onion, red grapes, honey, and citrus fruits. Quercetin is able to transport particular ions, such as zinc, across a cell’s lipid membrane, allowing zinc to fight viruses and pathogens.

Quercetin becomes supercharged when paired with Bromelain. Bromelain is a protein-digesting enzyme, such as protease and lipase. It is isolated from pineapple and activates natural killer cells, decreasing the majority of inflammatory mediators. It has been shown to have a significant role as an anti-inflammatory agent.

I recommend 1000 mg of Quercetin Bromelain to my patients, divided into 2 doses. If they are sick, I advise that they double the dose.

The third highly synergistic supplement is zinc. It has antiviral activity by either improving immune cell function that counter viral infections or by reducing the ability of viruses to multiply. Low zinc levels can increase your risk of disease and illness.

You need zinc to preserve natural tissue barriers, such as the respiratory epithelium that prevents pathogens from entering your body. Having a zinc deficiency can highly likely be added to the factors predisposing individuals to infection and detrimental progression of COVID-19. I recommend 50 mg daily. Here is the one that my patients and I use.

Intermittent Fasting

You can reset your immune system with fasting. Research published by the University of Southern California has shown that prolonged fasting can lead to the regeneration of the cells of your immune system. When you start to fast, your body will break down certain amounts of white blood cells, which play a key role in your immune system. It knows that your body must start conserving energy, and one way it does this is by getting rid of old/damaged immune cells. This triggers the creation of new cells, helping increase the number of immune boosting cells in your body.

When you stop eating, cells that support the immune system leave your bloodstream and migrate to bone marrow, which is full of nutrients. Here, they regenerate and become even stronger, resulting in your body being better able to resist infection. There are many benefits to restricting your eating times. You can read more about it on my blog about intermittent fasting here.

Fresh Air and Nature

We all know that fresh air is good for you. But science has shown that it also has a positive effect on your immune system. Fresh air increases how much oxygen you get, in turn helping white blood cells function better to kill pathogens, thus boosting your immunity. One thing to remember is that air quality not only affects the environment, but also affects the immune system. Air pollution can damage trees and crops in a few ways. Ground-level ozone, commonly referred to as smog, can reduce agricultural crop yields, reduce the growth and durability of tree seedlings. Air pollutants can also activate your body’s immune responses. It triggers an inflammatory cascade of events, aiming to protect your body from foreign invaders. Your best bet is to spend time outside, preferably in nature, during early morning or late afternoon. Sitting on the ground, touching the dirt, and walking in nature increases your microbiome diversity- helping boost your immune system. Inside your home, open your curtains and windows to let fresh air in and aim to use environmentally clean products.

Final Word

As you can see, your lifestyle does affect your immune system. Healthy habits and small lifestyle changes can have a huge impact on your health and well-being this season. Your best defense against flu and virus season is building up your own immune system. For a more personalized plan for optimal immune function, the first step for insight would be to become a patient, get bloodwork done, and then I can optimize your health with a plan that works for you. Schedule a complimentary 15 min call to get started. If you are a patient, you can order any of these items in your patient portal. I am happy to answer any of your questions in the portal.

Wishing you all a safe, healthy Holiday Season.