The old saying, “An apple a day can keep the doctor away,” may have truth behind it after all. Eating nourishing foods rich in certain vitamins can help your immune system fight off illness.

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We talked to registered dietitian Julia Zumpano, RD, LD, for a closer look at these vitamins, what foods you can find them in and how they can help keep you healthy. Here’s what she had to say:

  • Vitamin C is one of the biggest immune system boosters of all. In fact, a lack of vitamin C can even make you more prone to getting sick. Foods rich in vitamin C include oranges, grapefruits, tangerines, strawberries, bell peppers, spinach, kale and broccoli. Daily intake of vitamin C is essential for good health because your body doesn’t produce or store it. The good news is that vitamin C is in so many foods that most people don’t need to take a vitamin C supplement unless a doctor advises it.
  • Vitamin B6 is vital to supporting biochemical reactions in the immune system. Vitamin B6-rich foods include chicken and cold water fish such as salmon and tuna. Vitamin B6 also is found in green vegetables and in chickpeas, which is the main ingredient in hummus.
  • Vitamin E is a powerful antioxidant that helps the body fight off infection. Foods rich in vitamin E include nuts, seeds and spinach.

How to grocery shop to boost your immunity

A simple rule can help you when choosing fruits and vegetables at the grocery store or farmers market: The more colorful the fruits and vegetables are, the better.

“Try to eat a wide variety foods, and aim to eat fruit and vegetables from every color of the rainbow,” Zumpano says. “Your plate be more enticing to look at, and you will ensure that you’re getting as many health-boosting vitamins and nutrients as possible.”

It’s also important to know that you build a strong immune system by maintaining healthy eating habits over time. You can’t eat four oranges at breakfast and expect to be protected that day against catching a cold.

Can supplements help your immunity?

While vitamins and supplements can help fill in the gaps in your diet, the best way to load up on essential nutrients is to get them straight from food.

Your body absorbs and uses vitamins and nutrients better when they come from a dietary source. When it’s a vitamin or supplement, it’s often questionable how much you’re actually getting. Because supplements are regulated as foods, not as drugs, the Food and Drug Administration doesn’t evaluate the quality of supplements or assess their effects on the body.

Some supplements may have side effects, especially if taken before surgery or with other medicines. Supplements can also cause problems if you have certain health conditions. And the effects of many supplements haven’t been tested in children, pregnant women and other groups.

It’s especially important to avoid taking vitamin E supplements. Not only is there little clinical research showing that vitamin E supplements benefit your health, they may be harmful in some situations.

For these reasons, experts say it’s best to get vitamins through food rather than supplements.

“Talk with your healthcare provider if you’re thinking about taking dietary supplements,” Zumpano says.

Staying hydrated can boost your immune health too, Zumpano says. Water helps your body produce lymph, which carries white blood cells and other immune system cells. Try to avoid overdoing beverages that can made you dehydrated, like coffee. Or try eating more hydrating foods, such as cucumbers, celery or watermelon.

Best immune-boosting supplements

Winter bug season has landed and your office deskmate is already onto their third packet of Kleenex of the week.

Put your guard up: from superfood supplements to add to your coffee to 3D-printed vitamins tailored to your needs, these are the smartest immunity boosters for keeping that autumn cold at bay.

Bear Protect Supplement

Contains vitamin A and echinacea to defend against flu and office bugs. Vegan, gluten-free and sourced from small-scale farms, co-operatives and leading laboratories.

£50 | Net-A-Porter | Buy it now

Clean Greens: The Immunity Blend

The power of eight superfoods in one tablet for supporting the immune system, boosting energy and maintaining regular metabolism. Add to water, smoothies or energy balls.

£24.99 | Super U | Buy it now


The world’s first 3D-printed vitamin: fill out an online quiz and Nourished will post a month’s supply of edible supplement stacks to support immunity, gut health and energy levels.

From £19.99 | Get Nourished | Buy it now

Immune Boost Natural Immunity Capsules

A blend of Manuka honey, bee propolis, ginger root and royal jelly that supports the immune system and increases energy levels. Take two capsules a day.

£13 | Green Goddess Wellness | Buy it now

LQ Digestive Care

This drinkable, super-strength supplement contains 11 active ingredients to support daily digestive health and immunity.

£29.99 | LQ Liquid Health | Buy it now

ESBest product reviews are unbiased, independent advice you can trust. On some occasions, we earn revenue if you click the links and buy the products, but we never allow this to bias our coverage. The reviews are compiled through a mix of expert opinion and real-world testing.

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The immune system is essential for our survival and has several critical functions that protect the human body. It guards against damage, disease, and infectious organisms, including bacteria, fungi, parasites, and viruses in the environment.1-4 It can also recognize and destroy abnormal cells that originate from host tissues.1,4 The immune system can be broadly divided into 3 general functional divisions: the acquired (also called adaptive or specific) immune system, the innate or natural immune system, and the passive or borrowed immune system, which includes a newborn’s receiving antibodies from the mother through the placenta before birth and in breast milk after birth.1,2
The immune system functions by using an exclusion barrier: eliminating pathogens and tolerating nonthreatening sources of antigens, and maintaining a memory of immunological encounters (Table 1).5 Pharmacists are likely to encounter patients who need guidance on using nutritional supplements marketed to boost the immune system, particularly right before or during cold and influenza season. Pharmacists are in a pivotal position to educate patients about the proper use of these supplements. They can also be instrumental in determining whether nutritional supplements are appropriate and directing those with medical conditions to confer with their primary care providers when warranted.
Investigators have discovered that certain factors may influence the immune system, including medical conditions, chronic stress, and lack of sleep, as well as pharmacological agents like corticosteroids, tumor necrosis factor inhibitors, and immunosuppressants used to treat autoimmune disorders, immune-mediated disease, and conditions in transplant patients.6-9Chronic insomnia is connected with not only an increase in inflammatory markers but also immunodeficiency.9 Moreover, research results have shown that the immune system can be affected by the aging process and that there appears to be an association between immunity and nutrition in elderly patients, who tend to eat less, may have less variety in their diets, and experience loss of appetite caused by some medications and medical conditions.10

Some research has demonstrated that undernourishment and nutritional deficiencies of zinc, selenium, iron, copper, folic acid, and vitamins A, B6, C, and E have noteworthy influences on immune system responses.11 Being overweight or obese may also weaken the response.11 Investigators are continually exploring the effects of age, diet, exercise, psychological stress, and other factors on the immune response in animals and humans.12
Eating a balanced and healthy diet is critical, and the recommended essential nutrients that support immune health include vitamins A, C, B6, and E, as well as folate, selenium, iron, and zinc, according to the Academy of Nutrition and Dietetics.13 The use of prebiotics and probiotics may also influence the immune system’s response.13
According to new research, aging vessels connecting the brain and the immune system play critical roles in both Alzheimer disease and the decline in cognitive ability.14 Results of another study showed exciting information on the role of immunoglobulin A in pro- moting immune health and regulating the composition and function of gut microbiota.15
Immune-boosting supplements may contain one or more of the vitamins A, B, C, D, and E, along with trace elements of zinc and selenium (table 2). Some also contain Echinacea, ginger, and other herbal ingredients for immune enhancement. Other products marketed for immune support include prebiotics and probiotics. Some contain colostrum, which is rich in antibodies and immunoglobulins A and E that may provide immune-modulating benefits.16 Many other products marketed for strengthening the immune system may contain Echinacea, elderberry, and traces of zinc.16

A healthy diet is the best way to maintain a strong immune system. But nutritional supplements are a convenient and easy way to ensure that nutritional needs are met. Before recommending any supplements, pharmacists should screen for possible contraindications and drug-nutrient interactions. Patients who have medical conditions or take other medications should be encouraged to discuss these supplements with their primary care providers before using them. Additionally, patients should be prompted to always adhere to recommended doses and to use products only as directed. Patients should also be cautioned about taking megadoses of vitamins and to read labels to check for therapeutic duplications. During counseling, pharmacists can also remind patients about obtaining annual flu vaccines as well as maintaining immunization schedules for other recommended vaccines.
Yvette C. Terrie, BSPharm, RPh, is a consulting pharmacist and a medical writer in Haymarket, Virginia.

When you start to feel a cold coming on, or even worse, the flu, your natural instinct might be to guzzle down as much Emergen-C as humanly possible.

But is that really a good idea? Short answer: It depends.

“We all know we need certain vitamins to repair and heal our bodies, and zinc and vitamin C have been proven to help protect the body, before you’re sick or right at the start,” says Aileen Marty, M.D., a professor specializing in infectious diseases at Florida International University. Cold supplements can help cut the cold off at the knees, and reduce symptoms, she says.

According to a 2013 review on the efficacy of vitamin C for colds, it’s particularly useful for people who are super active or have physically strenuous jobs, but the jury is still out on whether it can do much for the general population (a few studies have shown it reduces the duration of colds by about a day, but not enough to be conclusive). Meanwhile, research has also linked zinc to faster recovery from cold symptoms.

(Get the latest health, weight loss, fitness, and sex intel delivered straight to your inbox. Sign up for our “Daily Dose” newsletter.)

More Isn’t Always Better

Here’s the catch: When it comes to water-soluble vitamins, like vitamins B and C, the body can only absorb so much. “If you take too much, you’re essentially wasting your money because you’ll just pee it out,” says Marty. (The same seems to go for zinc; the body only stores a minimal amount.) But, luckily, other than being a money-waster, taking a bunch of vitamin C won’t hurt you.

That’s not the case for several other vitamins that can be found in immune-boosting supplements. Fat-soluble vitamins A, D, E, and K, can cause issues when they’re taken in large doses. These are absorbed in the small intestines and then stored in the liver and fat tissues. It’s much easier to reach dangerous levels with fat-soluble vitamins because they build up over time. Vitamin A overdose, for example, can cause vision changes, bone pain, and liver damage. According to the National Institutes of Health, supplements are the the primary reason people experience vitamin A toxicity.

Unfortunately, though, experts aren’t sure exactly how much is too much. So, for now, most health professionals and nutritionists advise not taking any more than 100 percent of your recommended daily allowance (RDA) of any given vitamin or mineral through supplementation alone, Marty says. (You can find information on your RDA for some vitamins and minerals here.)

For the record: Immune-boosting supplements often contain concentrations of vitamins that far exceed your RDA. For example, one packet of Emergen-C Immune + Super Orange contains 1,667 percent of your daily value of vitamin C, and 500 percent of your daily value of vitamin B6. And one dose of Airborne contains nearly 17 times the RDA of vitamin C, more than 100 percent of the RDA of select B vitamins, 40 percent of the RDA of vitamin A, and a day’s worth of vitamin E.

If you follow the dosage instructions and only take the cold-fighting supplement for a short period of time, there’s very little risk of toxicity, Marty says. However, the longer you take high amounts of fat-soluble vitamins, the more they can build up in your body. That’s why these immunity-boosting supplements are only intended for short-term use, she adds.

Related: The Symptoms Of Colon Cancer That Every Young Woman Should Know

There’s A Better Way To Boost Your Immune System

“The best thing anyone can do is maintain good health every day by eating well and exercising,” says Marty.

It’s true. When it comes to vitamins and minerals, it’s always best to operate with a food-first mentality. If you’re looking for vitamin C, try yellow bell peppers, guava, kale, papaya, and strawberries, which all have more vitamin C than an orange. For zinc, add foods like shellfish and yogurt to your diet. Basically, as long as you’re eating a whole-foods diet that’s rich in a vegetables, produce, meats, and dairy, you should get all of the nutrients you need for a strong immune system. And if your doctor does find that you have any nutrient deficiencies, supplement that nutrient specifically, and follow your doctor’s instructions on dosage, she says.

Related: 10 Foods That Will Help You Survive Cold and Flu Season Without Getting Sick AF

Meanwhile, research shows that exercise can actually boost the cells that aid our immune system and lower inflammation. For example, a 2015 University of Houston study found that a single bout of moderate-intensity exercise, like jogging or lifting moderate weights, activates the immune system to fight off infection.

So maybe consider swapping out your supplements for a rainbow-filled plate—with a side of exercise.

Kristin Canning Kristin Canning is the health editor at Women’s Health, where she assigns, edits and reports stories on emerging health research and technology, women’s health conditions, psychology, mental health, wellness entrepreneurs, and the intersection of health and culture for both print and digital.

7 Immune-Boosting Supplements for a Healthier Winter

Photo: fizkes /

You’re likely willing to try anything to stay healthy this flu season (this flu season is literally the worst). And fortunately, on top of other immune-boosting habits you’re already practicing on the reg (sleeping eight hours a night, making exercise a habit) there are additional steps you can take to stay healthy-namely when it comes to your diet. (Related: Exactly How Contagious Is the Flu?)

“Vitamins and minerals with antioxidant properties can support a healthy immune system,” says Kelly Hogan, R.D., the clinical nutrition and wellness manager at the Dubin Breast Center at Mount Sinai Hospital. (Think: vitamin C, vitamin E, beta-carotene, zinc, and selenium.)

And while many can be found in healthy whole foods-fruits, vegetables, nuts, and seeds-there is a case to be made for supplementing a healthy diet this season. (Related: 12 Foods to Boost Your Immune System This Flu Season)

“Herbs are the original medicines, and many have antiviral and antibacterial activity,” says Robin Foroutan, R.D., a dietitian at The Morrison Center in New York City and a spokesperson for the Academy of Nutrition and Dietetics. Even more: “They’re totally safe, and many have great research to back up what generations before us already knew.”

Of course, no one vitamin or mineral is going to build your body into a fortress against infection. “In regards to ‘immune-boosting’ claims, I think we need to be careful,” says Hogan. Example: Some research suggests certain vitamins (C, for example) might ease cold symptoms, but finds that they’re not necessarily preventative in keeping said cold at bay.

But if you’re feeling a little under the weather (or just want to feed your body with more healthful nutrients), consider these supplements that dietitians swear by. (As always, make sure to check with your doctor before you start taking any supplements.)

Turmeric and Ginger Tea

“I personally like sipping on green tea or herbal teas with turmeric and ginger if I feel like I’m getting sick,” says Hogan. “They’re also packed with antioxidants and can help strengthen the immune system.” Teas and warm beverages are also super soothing, she notes-a perk if you’re feeling under the weather.

Try: Organic India Tulsi Turmeric Ginger Tea ($6;

Buffered Vitamin C

Vitamin C has long been used to support immune function. “Research to support its use as a supplement to prevent or shorten the duration of colds typically shows some benefit-some more marginal, some more significant,” says Stephanie Mandel, a holistic nutrition consultant at The Morrison Center.

She prefers “buffered” vitamin C-a form of the vitamin paired with magnesium, potassium, and calcium, which many people are low in. Another plus? “It’s easier on the stomach, so it’s a good option for people who are bothered by the acidity of vitamin C,” Mandel explains. Aim for 2,000 to 4,000mg per day.

Try: Buffered Vitamin C ($38;

Vitamin D3/K2

A study published in the BMJ found that vitamin D supplementation was effective in preventing acute respiratory infections. Pro tip: “It’s known that vitamins D and K work together in the body, so when you supplement with vitamin D, it’s a good idea to pair it with vitamin K,” says Mandel. (FYI, vitamins D and K are also fat-soluble, meaning that your body has to have enough healthy fat in order to reap their full benefits.)

Try: Vitamin D3/K2 ($28;


“As we come to learn more about how our microbiome works, we’re beginning to understand that certain strains of bacteria play specific roles in the body,” says Mandel. Both Lactobacillus plantarum and Lactobacillus paracasei are strains that have been shown to play a role in protecting against the common cold (and shortening its duration), she notes.

Try: Daily Flora Immune Probiotic Capsules ($35;


Extract from the elderberry has been shown to have antiviral, pro-immunity effects. “I love elderberry extract for supporting the immune system,” says Foroutan. Make your own extract by simmering dried elderberries in water, she notes. Or, pick up a product at your natural health foods store. “Just look out for added sugar, which is completely unnecessary because elderberry is naturally sweet and delicious,” she notes.

Try: Sambucus Fizzy Elderberry ($5;


Some research finds that andrographis, a bitter plant native to some South Asian countries, can play a role in weakening the symptoms of the common cold if you’re already sick. In fact, extracts of the plant have been used medicinally for centuries, thanks to their anti-inflammatory, antiviral properties. “These capsules aren’t the easiest to find, but it’s worth it,” says Foroutan.

Try: Gaia Quick Defense ($17;

Silver Hydrosol

Taken daily, silver in its hydrosol form (particles suspended in water-similar to colloidal silver) can help fend off general colds and the flu, says Foroutan. (In spray form, silver can also help with nasal congestion, she notes.) “It’s very, very, very diluted at about 10 parts per million,” she says. “There have been warnings about developing argyria from using silver products, but those risks are associated with using cheap products like elemental silver, ionic silver, or low-quality colloidal silver, which is why good manufacturing practices matter so much.”

Try: Sovereign Silver ($21;

The immune system is responsible for defending the human body against harmful microorganisms that cause illness and disease. Without the immune system, the human body would be exposed to these microorganisms that cause illness and diseases. Even with the presence of the immune system, a weak immune system cannot defend the body from disease and illness. The weaker the immune system, the greater the chances of falling sick. Therefore, it is important for one to have a stronger immune system especially during cold and flu season.

With all the work the immune system does, chances are the immune system can become weakened, but the good news is that you can support your immune system through proper nutrition and supplementation. While it’s always ideal to get important nutrients from food, some vitamins can be difficult to get enough of from diet alone. So, which supplements are really the best for immune system boosting?

Best supplements to boost your immune system.


Probiotics are quite effective for boosting the immune system. A 2009 study published in Annals of the New York Academy of Sciences, reported that probiotic supplements had a deep effect on the immune system function in animal models. The researchers arrived at the conclusion that probiotic supplementation could fuel the immune system without adverse effects.

Probiotics are affable bacteria that typically inhabit the gut and are optimize the immune system. About 70 percent of the immune system is controlled by what happens in the gut, and friendly bacteria are the essential part of the immune system. The bacteria adjust the immune system by increasing the number of definite white blood cells.


Adequate micronutrients in the body help the immune system to function at best. When there is a deficiency of micronutrients in the body, immunity is being suppressed and thus leaving the body susceptible to infections. Vitamin A, B6, B12, C, D, E, copper, folic acid, zinc, and selenium, according to an article published in the British Journal of Nutrition, all works to improve immune function in diverse ways.

Vitamin D

Vitamin D has been found to be quite effective in strengthening the immune system. Studies have found that sufficient amount of Vitamin D in the body helps reduces the chances of suffering from illness and diseases. Thus, taking vitamin D supplements fuels your body with the right amount of vitamin which helps in boosting your immune system.


Several scientific publications have reported on the effectiveness of spirulina in strengthening the immune system. Spirulina has a powerful nutrient known as polysaccharides – polysaccharides are widely known to be powerful immune system booster and also assisting in the prevention of several maladies.


Zinc has the natural ability to help the immune system function efficiently. Zinc is required for optimal function of different types of white blood cells that protect the body from illness and infection. Additionally, zinc helps in cytokine production, phagocytosis, and other immune system processes.

As mentioned earlier, a stronger immune system accounts for a healthy body and overall healthy living. You don’t need to have signs of a weak immune system before you think of boosting it, incorporate these supplements to your diet to help strengthen your immune system to work at best.

Dressing for transitional weather is already tough (jacket in the morning, tank top by afternoon), but preparing your immune system for the seasonal shift is a whole other story.

“With the change of seasons, there is an uptick of changing pollens and other allergens,” explains Melissa Rifkin, MS, CDN, and owner of Melissa Rifkin Nutrition LLC. “These allergens can irritate the lungs and nasal passages therefore leaving one more vulnerable to get a cold or virus.”

In order to maintain optimal health during seasonal changes, Rifkin suggests staying hydrated, clocking seven to nine hours of sleep a night, decreasing stress levels, and washing your hands often. But, there’s one more piece of this immune-boosting puzzle: Supplements, like the ones from NOW®, which can help you get the right doses of immunity-supporting nutrients so you can feel your healthiest self all year long.

And those seasonal wardrobe swaps you’re making? You should be doing the same thing with your vitamin and supplement regimen. “Using supplements to strengthen your immune system could help keep you healthy,” Rifkin adds. So while you’re switching over your closet, make some room in your medicine cabinet, too. Here’s what to add.

Keep scrolling to find out how to boost your immune system with a few tweaks to your medicine cabinet.

If the first thing you do when you start feeling under the weather is run to the grocery store for orange juice, you’re probably not surprised that the first supplement on the list is vitamin C, which helps support cellular function in the immune system, according to Rifkin.*

In addition to containing ample amounts of vitamin C from acerola (a South American fruit with one of the highest natural concentrations of vitamin C), NOW® Tru-C Veg Capsules “also contain carotenoids and flavonoids, which are phytonutrients that give fruits and vegetables their colors,” Rifkin says. “These phytonutrients give the body antioxidants and can assist vitamin C in strengthening immune health.”* Told you it wasn’t average.

Probiotics, but for your immune system*

You might be wondering what a probiotic has to do with your immune system (aren’t those just for gut health?), but your microbiome could actually have a bigger impact on your overall health than you might think.* And that’s where NOW® Respiratory Care Probiotic comes in.

L. acidophilus, the probiotic strain used in this supplement, has been associated with seasonal wellness, according to Rifkin.* And science backs her up: Over 60 studies have shown L. acidophilus NCFM® supports a strong immune response to seasonal respiratory issues.* It’s a win-win for your digestive system and your (not) stuffed-up nose.*

Herbs on herbs

The finishing touch to your immune-boosting supplement routine is NOW® AlliBiotic, which contains a mix of herbs that have been used for hundreds of years to strengthen the immune system, Rifkin says.*

Within this botanical formula is olive leaf extract, elderberry, oregano oil, and garlic (no, it’s not just a Halloween thing). Garlic: Now your go-to for warding off vampires, bad dates, and seasonal struggles.*


Sponsored by NOW®

Top photo: Getty Images/LaylaBird

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.

Best immune booster supplements

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