9 Supplements That'll Boost Your Immune System, According to a Registered Dietitian

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Sydney Greene is a registered dietitian nutritionist who offers integrative, customized nutrition counseling and coaching for individuals. With cold and flu season in full swing, we asked her to share the best supplements to boost immune health. Keep scrolling to discover her top picks, ones she says can help set the foundation to a healthier you.

Sleep, adequate water, plenty of fruits and vegetables and moderate movement—there is not one supplement that can take the place of these key practices. That said, there are some herbs, plants, vitamins, and minerals that can be taken to support a strong foundation. Many of the following supplements are safe for general use however it is important to discuss supplement changes with your health care provider and seek medical help for illness.

Below, discover some of the best supplements to help boost your immune system.

Renew Life Ultimate Flora Probiotic Extra Care Go-Pack

Probiotic products consist of live, active bacteria that show a health benefit. Taken to support or improve a person’s gut microbiome (the presence of all living microorganisms within a person’s digestive tract), probiotics can have a significant impact on mood, digestion, and immunity.

Research exploring the impact of beneficial bacteria on immunity has been exploding. The immune cells inside of the digestive tract play a major role in maintaining homeostasis of the immune system. Managing optimal ratios of good bacteria (probiotics) in the gut has been shown to promote intestinal epithelial cell survival, enhance gut barrier function, and stimulate protective cell responses which in turn can prevent infections or shorten the duration.

Renew Life’s Extra Care probiotics provide 50 billion live cultures from 12 different probiotic strains, designed to re-establish digestive balance. Ensuring quality and potency through expiration, Renew Life’s capsules are designed to be delayed-release, making sure the contents make it past the acidic environment of the stomach. As an added bonus, these probiotics do not need to be refrigerated, a plus when shipments might be delayed, routines are disrupted by travel or emergency times without refrigeration.

Hilma Immune Support

Hilma Immune Support

Time and time again we read ingredients labels on supplements without any idea of what's actually inside. But that's not the case with Hilma, an easy-to-use packet formulated with just six essential ingredients clinically proven to boost immune system function. That's right—no mystery ingredients, just a heaping dose of vitamin C, echinacea, zinc, ginger, turmeric, and ivy leaf extract.

The brand is super transparent (and picky) about those ingredients too, with detailed reasons—all backed by science—for why each one made the cut listed directly on their website. We also love that there's less than one gram of sugar, no gluten or nuts, and all packets are vegan-friendly.

New Chapter Elderberry Force

New Chapter Elderberry Force

Research examining the use of elderberry for immunity has shown moderate evidence to support the reduction of the duration and symptoms of colds, not the prevention of them. Elderberry extract seems to help the production of inflammatory cytokines, proteins that are released in the body to fight infection.

One randomized, double-blind placebo-controlled clinical trial of 312 adults traveling from Australia to an overseas destination aimed to investigate if a standardized elderberry (Sambucus nigra L.) extract would have beneficial effects on physical health. Placebo group participants had a significantly longer duration of cold episode days and the average symptom score over these days was also significantly higher however this study was sponsored by the producer of the elderberry extract.

According to Consumer Labs, an independent product testing company, New Chapter Elderberry Force contained the highest amount of anthocyanosides compared to the 10 other popular products tested. Anthocyanosides are the compounds that give elderberries their purple color and seem to stimulate the immune system. These capsules are also vegan, gluten-free, non-GMO and free of artificial colors and flavorings.

Amazing Grass Protein Superfood The Original

Amazing Grass Protein Superfood Original

Amazing Grass’s Original Protein Superfood covers all nutrient bases. Including 20 grams of complete plant-based protein, seven different greens, and two servings of fruits and vegetables, this is the perfect nutrient boost to add to a daily routine or to keep on hand as an immunity add on when routines are interrupted.

More specifically, this product contains 12% of energy-boosting, plant-based iron and 20% of vitamin A which supports adaptive immunity, the body’s ability to adapt and respond to foreign invaders.

Amazing Grass sources their greens from a family farm in the United States and uses a low temperature dehydrator to retain nutrients. This mix does not include Stevia or any sweeteners, so it’s best enjoyed as a base for a smoothie, soup or sauce rather than having on its own.

Nature's Bounty Echinacea

Echinacea consists of a group of nine plant species and has been traditionally used for colds, flu, and other infections. Research has shown some ability to reduce symptoms of the common cold and flu and maybe prevent occurrence however results vary based on the type of echinacea used as well as the dose.

A recent study showed that taking echinacea three times a day during the cold season modestly prevented cold occurrence. Nature’s Bounty has been third party tested by Consumer Labs, is free of gluten, wheat, and yeast and contains 1,200 - 2,400 mg of E. purpurea (one of the species of echinacea most commonly studied).

Kirkland Signature Daily Multi

The efficacy of vitamins and minerals depend on one another for their absorption and activation. When taking a multivitamin you take various nutrients all at once, which leads to optimal processing in the body. Multivitamins contain potent immune supporters such as vitamin C, vitamin D, magnesium, iron and B vitamins.

Kirkland’s supplements are one of a handful of brands on the market that feature the seal of approval and quality from United States Pharmacopeia (USP). A USP Verified seal means that the product contains the ingredients listed on the label, in the declared strength and amounts. It means that the product does not contain harmful levels of specified contaminants. It also ensures that products are made according to FDA and USP Good Manufacturing Practices, using sanitary and well-controlled processes and tests to make sure the product will break down and dissolve within a specified amount of time so the active ingredients can be released and absorbed by the body.

Nordic Naturals Omega 3D

Nordic Naturals Omega 3D

This supplement combines two potent immune nutrients in one: vitamin D3 and the essential fatty acids EPA and DHA. Vitamin D deficiency has been associated with increased infections.

Fish oil has been researched for a wide variety of uses such as improving mood, supporting heart health, slowing cognitive decline, decreasing cancer risk among many others. Fish oil has such a far-reaching impact across the body because the essential omega 3 fatty acids found in fish oil bolster cell membranes, helping them perform their function optimally. Vitamin D is a fat-soluble vitamin, meaning it can only be adequately absorbed when it has fat molecules to travel with it through the body.

Nordic Naturals Omega 3D pairs 1000 IU of vitamin D3 with omega 3 fatty acids from wild, sustainably sourced fish making each capsule primed for efficient digestion and absorption. In addition to 1000 IU of vitamin D3, this product provides 745 mg of eicosapentaenoic acid (EPA) and 500 mg docosahexaenoic acid (DHA) per serving; both of these amounts are at the higher end of suggested daily intake. The combination of vitamin D3 and EPA/DHA packs a potent punch to support overall immunity. 

Source Naturals Vitamin D-3 Liquid Drops

Source Naturals

Vitamin D has been shown to be beneficial in supporting the body’s immune system in many ways. For anyone who has a hard time with pills, this product is for you.

These vitamin D3 liquid drops provide 2000 IU per serving however for those that want more or less vitamin D, dosing can be adjusted directly by the user by increasing or decreasing the number of drops consumed. Free of yeast, dairy, corn, soy, wheat, egg and gluten, this product is an excellent choice for those with food allergies and/or intolerances.

Zand HerbaLozenge Elderberry Zinc

Zand Herbalozenge

Many studies show that supplementing with zinc, specifically in lozenge form can reduce cold symptoms such as muscle aches, runny nose, congestion, and cough, however these studies showed effectiveness with frequent and higher doses. It is important to note that excessive intake of zinc can lead to copper deficiency so frequent use of lozenges should be limited to a few days. 

In addition to reducing symptoms, zinc supplementation has been shown to shorten the duration of colds. Both zinc gluconate and zinc acetate have been studied and there does not appear to be a major difference between the two.

Zand’s Herbalozenge has been third party tested by Consumer Labs and contains five milligrams of zinc gluconate per lozenge. This product also contains a blend of other herbs known to soothe and help with cold symptoms such as licorice and eucalyptus.

Ingredients You Should Consider

Written by Amy Lawrenson

Reviewed by nutritionist and holistic wellness expert Kimberly Snyder

We called on nutritionist Sarah Flower to take us back to basics to reveal the supplements we should be taking—and the three we can afford to ditch. Here's what she recommends:

Turmeric: This is a very powerful anti-inflammatory showing the highest measurement on the ORAC scale. The bioactive compound in turmeric is curcumin, which gives turmeric its bright yellow color. The use of turmeric for medicinal reasons dates back over 4000 years. In Ayurvedic medicine, it is used as a cleansing and detoxifying agent. This has been shown to help with a variety of inflammatory conditions including arthritis, as well as helping to soothe IBS. You can add turmeric to your food, but to ensure your body can absorb the nutrients efficiently, you should combine it with black pepper. 

Magnesium: This really is a hero nutrient and almost every fundamental process in our body needs a good supply of it. Magnesium is required for the production and stability of the ATP molecule, which provides energy for basic bodily processes. These range from the processing and transporting nutrients to making enzymes and activating cellular pumps so that important substances can move in and out of each cell.

Women, in particular, can suffer a range of hormonal problems, from PMT symptoms right through to menopause due to low magnesium. In fact, our hearts are totally dependent on it. Magnesium deficiency has been shown to increase platelet aggregation, which contributes to the kind of clotting seen in heart attacks, pulmonary embolism, and strokes, which is why those with lower levels are more likely to have heart conditions.

Magnesium is also known as an anti-stress mineral, as it helps relax muscles, has a nourishing effect on our nervous system, and helps improve flexibility and tone of blood vessels. Those who suffer from anxiety, depression, and migraines are usually shown to be deficient in magnesium. It’s also beneficial to conditions such as chronic back pain, leg cramps, and IBS. Low magnesium has also been linked to fibromyalgia and osteoporosis.

Vitamin D: Whether it’s going for a short walk on your lunch break or a run in your local park before or after work, getting outside and moving can help to boost your mood, lower your blood pressure and reduce stress.

Vitamin-D deficiencies can affect our immune system, respiratory system (especially incidences of asthma), depression, heart disease, multiple sclerosis, diabetes, and even cancer. Vitamin D helps lower our blood pressure and helps to keep us calm and less anxious. It has even been shown to help the body break down the stubborn fat cells.

We can, of course, take a supplement or even get some vitamin D from food (such as fish and eggs) but studies have shown that the conversion from sunlight is much more powerful and has more of an impact on health. There are two supplement forms: Vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). Vitamin D3 is produced by the lanolin in sheep wool. D2 is produced from ergot (a type of fungus). I recommend vitamin D supplementation in my practice, but prefer the vitamin D3 (cholecalciferol) form, as I feel it absorbs better.

Ingredients You Should Avoid

B Vitamins: Eight vitamins make up the vitamin-B complex, and they each play an important role in keeping our bodies healthy. Whilst many of the B vitamins work alongside each other, each has its own specific benefits such as promoting healthy skin and hair or preventing memory loss and migraines. Though these nutrients contain numerous benefits (which might make you more inclined to reach for some supplements), chances are the average person is already getting plenty of B vitamins—unless they are on a special diet that eliminates certain food groups—from the food they eat. For example, B1, which is known to help the body make healthy new cells and is often called the "anti-stress" vitamin because of its ability to protect the immune system, can be found in whole grains, peanuts, beans, spinach, or kale. Each B vitamin has enough contents in various everyday foods that make it unnecessary to take them in supplements.

Selenium: Selenium is a trace element that is important for the body’s immune system and for reproduction. It has received particular attention because of its antioxidant properties, which help protect cells from damage. Selenium is available as a supplement, however, numerous evidence has shown that too much can cause bad breath, fever, nausea, and liver, kidney, and heart problems. Some vitamins and minerals that are consumed higher-than-recommended may interfere with nutrient absorption and cause unwelcoming side effects. It seems unnecessary to put your body through this when you only need 400mg of Selenium a day, which you can easily get from the foods that contain this mineral. For example, sources of it can be found in Brazil nuts, brown rice, broccoli, or salmon.

Vitamin E: This is often used for treating and preventing diseases of the heart and blood vessels. Vitamin E can be found in many foods including vegetable oils, cereals, meat, poultry, eggs, fruits, vegetables, and wheat germ oil, but it is also available as a supplement. It is highly recommended that people make a conscious effort to ensure they are consuming vitamin E by eating a well-balanced diet that is high in fruits, vegetables, and whole grains rather than from supplements. This is because vitamin E supplements can be harmful, especially for individuals who already suffer from illnesses (such as cancer), and can increase the risk of bleeding in people taking antiplatelet medication.

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