But what is vitamin C, exactly, and how does it support our immune system? Now that we’re in the thick of cold and flu season (not to mention dealing with COVID and RSV!) here’s everything you need to know.

What Is Vitamin C?

First, let’s take a look at exactly what vitamin C is. “Vitamin C is a plant-derived antioxidant that’s found predominantly in veggies and fruit,” explains Jaclyn London, MS, RD, CDN Head of Nutrition & Wellness at WW (Weight Watchers).  “This class of compounds helps to support overall immune function and general well-being by protecting your body’s healthy cells from damage.” The body also uses vitamin C to make collagen which is a springy type of connective tissue that makes up parts of your body and helps to heal wounds. “ If you don’t get enough or no vitamin C for weeks, you can get scurvy, a condition causing fatigue, gum inflammation and bleeding, joint pain, and poor wound healing,” adds Brenda Braslow, RD.“The daily recommended allowance for adult men is 90 mg per day and 75 mg per day for adult women,” she says. 

The Benefits of Vitamin C

A diet that has the recommended amount of vitamin C can help prevent disease as we age. “Over time, a diet that provides antioxidants, including vitamin C, from plant foods can help to promote healthy cell function, and therefore, help to decrease risk of chronic disease on the whole,” says London. “Vitamin C helps protect vision by inhibiting the progression of cataracts and macular degeneration, it increases resistance to infection, colds, flu, and more,” explains Elizabeth Somer, MS, RDN,and Personal Nutrition Medical Advisory Board Member. She adds that vitamin C can also regulate cholesterol production, help lower blood pressure, and is important in the formation of the stress hormones produced by the adrenal glands.  7 Foods You Should Eat to Keep Your Eyes Healthy

Should You Take Vitamin C Supplements?

There are all kinds of varieties of vitamin supplements in the pharmacy, but are they worth taking? “Most people get adequate vitamin C through their diet. Taking a daily multivitamin can also provide a little additional vitamin C, often about 100 mg per supplement, so an additional high dose vitamin C supplement is not necessary,” says Braslow. London agrees, adding that unless a physician has recommended it for the treatment of a medical condition, then adding in supplements will have little to no benefit. “Vitamin C belongs to a class of vitamins that are water soluble, meaning what your body can’t use, you’ll excrete through the urinary tract as well as your GI tract.” Below, you’ll find a list of the very best dietitian-recommended vitamin C foods.

Best Vitamin C Foods

Plums 

Braslow says 1 medium purple plum has 6 mg of vitamin C. It’s also rich in potassium, vitamin E and the antioxidant lutein.

Chili peppers

¼ cup chopped green chili peppers has 91 mg of vitamin C, according to Braslow. 

Sweet yellow peppers

The vitamin C content of sweet or bell peppers increases as they mature. “What makes this so great for those of us trying to eat more food sources of vitamin C is that it’s a perfect ingredient and condiment, but also easily adapted to be a snack in its own right,” says London. Just one-half cup of yellow peppers provides 137 mg of vitamin C.

Red peppers

“A half cup of sweet, sliced red peppers arguably has the mostvitamin C of any vegetable or fruit,” says London. She adds that it’s the perfect ingredient or condiment that can be adapted into a snack. “One half cup of peppers will provide up to 95 mg.”

Green bell peppers

One ounce of sauteed peppers provides up to 49.5 mg of Vitamin C. 

Oranges or orange juice

One medium-sized orange provides up to 70mg of vitamin C which is 78% of the daily value. A mandarin orange has 24 mg.  Start your day off with a glass of orange juice. Braslow says drinking  6 ounces of orange juice has 93 mg of vitamin C.

Guavas

Braslow says half of a medium guava provides 63 mg of vitamin C. Guava fruit is also a great source of fiber. 

Thyme

“One teaspoon of dried thyme has 1 mg vitamin C,” says Braslow. Even just sprinkling a couple of tablespoons of fresh thyme over your meal adds up to 7 mg of vitamin C to your diet.

Parsley

Two tablespoons of fresh parsley contain 10 mg of vitamin C, providing 11% of the recommended daily value. 

Spinach

A half cup of cooked spinach has 9 mg of vitamin C. There are a variety of spinach options including savoy spinach, flat spinach, and semi-savoy spinach. 

Kale

“60% of the daily value for vitamin C per ½ cup, cooked serving of kale is up to four times what you’ll get from spinach,” says London. She suggests including it when sauteing, as a swap for romaine lettuce in sandwiches, or as part of a hearty winter soup.

Kiwi

“One medium kiwi packs 70% of the daily value for vitamin C,” says London. “ It’s a tasty and slightly-surprising addition to breakfast parfaits or eaten sliced as part of a snack.”

Broccoli

“One cup of broccoli packs up to 220% of the daily value for the nutrient and is easy to cook quickly in a saute pan with a little bit of garlic and olive oil or butter,” says London. 

Brussels sprouts

According to London, a ½ cup of cooked brussels sprouts packs 48 mg of vitamin C, which is about 53% of the daily value. “These are a great choice this time of year since you can drizzle olive oil and stick ‘em on a sheet pan for roasting. I’m also loving Brussels sprouts in the air-fryer.”

Lemons

London says one way to shake things up and get your water and vitamin C in is to add lemons to your drink. “Per half cup, lemon juice will provide more than half of the DV for vitamin C and it also adds tangy tartness to an otherwise unflavored sparkling beverage.”

Bok choy

“All cruciferous veggies provide some vitamin C,” says London. Bok Choy is also rich in Vitamin K.  

Strawberries

“Fresh or frozen, strawberries are a great source of vitamin C and provide up to 50% of the daily value for the nutrient per half cup,” says London. She suggests using it as a topping with plain, unsweetened Greek yogurt or as part of a dessert. You can also use it as a simple, lower-sugar swap for jelly on your peanut butter and jelly sandwich. 

Tomatoes

“Tomatoes are also a great source of vitamin C and are easy to incorporate, from canned tomatoes used in sauce or stew to fresh tomatoes thrown into a quick chopped salad,” suggests London. She says one cup of cherry tomatoes packs up to 30% of your daily value of vitamin C. 

Snap peas

Snap peas, as well as sugar snap peas, are a great source of vitamin C, providing 100% of the daily value in just 3.5 ounces. 

Cantaloupe

A cup of cubed cantaloupe contains over 200 mg of the recommended daily value of vitamin C. 

Potatoes

“A medium baked potato will provide about 30% of the daily value and is another go-to staple that’s easy to add as a side dish to meals, or, my personal favorite, as a quick and easy weeknight dinner of loaded baked potatoes with black beans, tomatoes, scallions, part-skim cheese, greek yogurt, and hot sauce," says London. Braslow adds that you shouldn’t throw away the peel, which is packed with nutrients! 

Cauliflower

“A half cup of cooked cauliflower packs up to 1/3 of your [daily value] for vitamin C, and it’s easy to incorporate now more than ever in the form of frozen, pre-prepped cauliflower rice, which you can find in your produce aisle at your local grocery store, or in the freezer aisle, making it that much easier to add to instant-rice to slowly introduce veggies into more meals and snacks,” says London. 

Grapefruit

Half a grapefruit contains 44 mg of the recommended daily value. 

Pineapple

Pineapples are rich in vitamin C, providing 131% of the daily recommendation. 

Mango

Mangoes are naturally high in vitamin C and beta-carotene.One cup of sliced mango provides 60.1 mg of vitamin C. Next up, here are 66 immune boosters for flu season.

Sources

Jaclyn London, MS, RD, CDN Head of Nutrition & Wellness at WW (Weight Watchers)Elizabeth Somer, MS, RDN, and Personal Nutrition Medical Advisory Board MemberBrenda Braslow, RD.National Institute of Health: “Vitamin C”  25 Best Vitamin C Foods and Drinks  Including the Best Fruits - 8