Vitamin C and Immunity: What It Can (and Can’t) Do, Plus More Immunity Supplements to Try

Last Update: March 21, 2024

As more people venture back out into the world—whether to work, to the classroom, to travel, or simply to stores and restaurants—immunity is especially important. With cold and flu season on its way and COVID-19 still circulating, now is a great time to stock your medicine cabinet with some go-to immunity supplements—like the new wellmade by Thrive Market Liposomal Vitamin C.

We consulted with doctors, nurses, and nutritionists to answer some of the most common questions about vitamin C and compiled a list of some other immune system boosters to try.

What is vitamin C?

Vitamin C, also called ascorbic acid, is a water-soluble vitamin and antioxidant. Supplement junkies, take note: Vitamin C was actually the first vitamin to be synthesized and chemically produced, says Megan Brynok, a Functional Diagnostic Nutrition Practitioner and women’s health expert. Since then, it’s gone on to become one of the more popular and talked-about vitamins, showing up everywhere from skincare products to the labels on pretty much every bottle of orange juice.

Your body doesn’t produce vitamin C on its own, so it’s important to get this essential nutrient from your diet—or, in some cases, a combination of diet and supplementation.  

What does vitamin C do?

Vitamin C has many important functions in the body, including:

How much vitamin C do I need?

The Mayo Clinic recommends 90 milligrams of vitamin C per day for adult men, and 75 milligrams for adult women.

You don’t necessarily need to supplement with vitamin C if you eat a varied diet with lots of fresh fruits and vegetables, but taking a supplement can help to fill in any nutrient gaps. People who may be at increased risk of vitamin C deficiency include those who smoke or are frequently exposed to secondhand smoke, people with certain cancers, and people with certain gastrointestinal issues that may affect nutrient absorption. 

What are some good vitamin C foods?

Foods high in Vitamin C include:

  • Citrus fruits (like lemons and oranges) and their juice
  • Red bell peppers
  • Broccoli
  • Brussels sprouts
  • Kale, spinach, and other leafy greens
  • Strawberries 
  • Kiwi
  • Papaya
  • Guavas
  • Tomatoes
  • Pineapple
  • Mango

While the vitamin C you get from food and the vitamin C you get from supplements is chemically the same, vitamin C foods contain other beneficial compounds that may impact the vitamin C’s bioavailability, or how much of a nutrient the body is able to absorb and use, explains Heather Hanks, a nutritionist with USA Rx. “Your body much prefers natural sources of anything,” she adds. For that reason, it’s best to start with a foundation of a healthy, balanced diet, then add supplements under the care of your physician to fill in any potential gaps. 

Vitamin C and immune system health

When you hear “vitamin C,” chances are you immediately think “immunity.” So it might surprise you that the science on vitamin C and immunity is, at best, mixed. Vitamin C won’t keep you from catching the common cold (or other illnesses, for that matter), but studies do suggest it may shorten the duration of said cold.

So if vitamin C isn’t actually an immunity panacea, where does the confusion come from? “Research shows that vitamin C supplementation, even in large doses, is not so helpful for preventing the cold and flu, but it is effective in reducing the severity of symptoms and duration,” explains Functional Medicine Dietician Krissy Carbo. She adds that “research does not always consider factors that decrease vitamin C absorption in its subjects that will skew results of the study.” Because vitamin C is absorbed in the small intestine, she explains, compromised gut integrity caused by common digestive issues like inflammatory bowel disease and celiac disease can reduce its absorption. Carbo’s advice? Get your gut health in check first before adding additional supplements to your routine. 

That doesn’t mean you should skip vitamin C altogether; in fact, almost all the experts we spoke to, from doctors and nurse practitioners to dieticians and nutritionists, said it’s worth having in your routine. “I would say there is good data to support the use of vitamin C in certain circumstances,” says Arielle Levitan M.D., author of the book The Vitamin Solution. “It has been shown to play a role in immunity and to shorten the duration of certain respiratory infections.” 

Dr. Levitan adds that, as with any supplement, dosage is important—and not one-size-fits-all. “The challenge…is knowing how much to take [and] the answer varies from person to person. We all have different vitamin needs depending on our diets, lifestyle, and health concerns.” (Translation: always talk to your doctor before starting a new supplement.)

While vitamin C on its own won’t necessarily give you impenetrable immunity (so keep washing those hands and eating those fruits and veggies), it does support your immune system indirectly in a few ways. “Vitamin C has gained a reputation for boosting immune system function primarily because it is needed to make two crucial compounds that strengthen immunity, glutathione and nitric oxide,” explains Jamie Hickey, a NASM/FMS certified trainer, registered dietician, and founder of Truism Fitness. Glutathione is an antioxidant produced in the cells that supports immunity, and nitric oxide is a vasodilator, meaning it relaxes the blood vessels, allowing nutrients and oxygen to circulate efficiently through the body.

Vitamin C also helps the body absorb and store iron, an essential mineral that supports the development of immune cells. According to registered dietician Trista Best, MPH, RD, LD, people who follow a plant-based or vegan diet should be particularly focused on vitamin C, since it helps the body absorb iron from plant-based food sources.

What is liposomal vitamin C?

Liposomes are tiny, spherical bubbles (called vesicles) made of a lipid bilayer that’s similar to a cell’s membrane. Those little liposome bubbles serve an important purpose in medicine: they protect drugs and supplements from pH changes as they travel through the body and deliver them directly to the cells where they’re needed. Liposomal vitamin C is a vitamin C supplement that uses this unique delivery system.  

Is liposomal vitamin C better than regular vitamin C?

Remember how we said that vitamin C is water soluble? That means it dissolves in water (as opposed to vitamins that are absorbed with fats in the diet, like vitamins A, D, E, and K). Vitamin C’s water solubility also means the body doesn’t store it, and it can be flushed out of the system easily—sometimes before it’s had a chance to have its full effect. 

Our wellmade by Thrive Market Liposomal Vitamin C is encased in a sunflower oil-based lipid sphere. This creates a lipid barrier that helps the vitamin C travel through the digestive tract and aids the vitamin’s absorption into the bloodstream. Like all of our wellmade by Thrive Market supplements, Liposomal Vitamin C is rigorously third-party tested for purity and potency and free of synthetic fillers.

How to use wellmade by Thrive Market Liposomal Vitamin C

Thanks to its liquid form and all-natural flavors—Citrus Vanilla and Citrus Vanilla Elderberry—wellmade by Thrive Market Liposomal Vitamin C is an easy addition to any healthy routine. Simply take a spoonful straight, or mix one into sparkling water and boost your vitamin C while you hydrate.

More immune system supplements to try

To stay healthy during cold and flu season (and year-round), start by eating a balanced diet that’s filled with plenty of fresh fruits and vegetables, staying hydrated, getting enough sleep, and managing your stress. (Stocking up on hand sanitizer isn’t a bad idea either). 

Want to bolster your routine further? Try these additional supplements known or thought to support the immune system:

Omega-3 fatty acids

Omega-3 fatty acids like ALA and DHA have been shown to help regulate the immune system. You can get omegas through your diet, from foods like fish and seeds, or from supplements; both fish oil and plant-based options are available. 

Vitamin D

Studies have shown that a vitamin D deficiency can lead to greater risk of infection. While you can get vitamin D from foods like fish, meat, and dairy (as well as sun exposure), those who eat a plant-based or vegan diet may benefit from adding a supplement. 


Elderberry has been used for centuries as a health remedy, and more recent research suggests its potent antioxidant effects may stimulate immunity. You can find elderberry in many forms, including syrup, gummies, and tea.


Because digestive health and immunity are closely linked, a probiotic that adds beneficial bacteria to the gut can be an ally during cold and flu season. To reap the potential health benefits of probiotics, you can also load up your diet with fermented foods like kombucha, sauerkraut, and yogurt.


This mineral, which can also be found in red meat, poultry, and whole grains, is essential for immune function.

Herbs & Herbal Formulas

Although formal research into the efficacy of homeopathic treatments is limited, many people swear by traditional plant remedies like echinacea, ginger, astragalus, garlic, and eleuthero for keeping their immunity up. Blended formulas like Gaia Herbs Quick Defense and Source Naturals Wellness Formula are an easy way to add multiple herbs to your routine.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment and before changing your diet or healthcare regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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Kirby Stirland

Kirby Stirland is a writer, editor, and New York transplant living in Los Angeles.

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