IF YOU LOOK at the advertising behind some of vitamin C supplements, you’ll likely see language that reads kind of like this: Vitamin C is a super-nutrient, one that boosts your immunity. People have been taking C to stop colds and flus for years, so it’s proven. So why not take a supplement to protect against diseases—especially during the fall and winter months?
Now let’s set some facts straight. Vitamin C does have some powerful health benefits. Vitamin C helps your body make collagen (good for skin and bones), absorb iron (good for muscle growth), and create carnitine (good for turning dietary fat into energy).
Vitamin C is also an antioxidant, so it helps combat free radicals caused by chronic stress and protect your immune cells as they fight off an infection. What it doesn’t do is banish colds and the flu.
Where Did the Claim That Vitamin C Stop Colds Come From?
VITAMIN C HAS been of interest as a treatment for respiratory infections since the 1930s. But vitamin C as a solution to the cold didn’t take off until the 1970s when Nobel Prize winning chemist Linus Pauling stated that clinical trials showed ample evidence of vitamin C preventing the common cold.
It’s been decades since Pauling made vitamin C popular—and the boom of vitamin C supplements. Since then, multiple clinical trials have looked to validate these claims…with little success. (At the height of the pandemic, there was also discussion of vitamin C supplements as a way to stave off COVID, which has since been debunked.)
What is known is that vitamin C may decrease the severity of a cold by 15 percent. A few clinical trials have also seen evidence of vitamin C shortening the duration of a cold. This occurred when people were taking 6 to 8 grams of vitamin C per day. But complete prevention? Not likely.
The recommended daily intake of vitamin C is 90 milligrams for adult men. Although the NIH does say taking at least 200 milligrams a day of vitamin C may be helpful for people who are prone to getting sick: those who exercise intensely, are exposed to cold environments, or have vitamin C deficiency.
The Major Downside of Taking a Vitamin C Supplement
YOU CAN OVERDO it with vitamin C.
People should not be going over 2,000 milligrams of vitamin C per day. That’s not just for supplements. It’s including your total vitamin C intake you get from food and beverages. (The mean intakes of vitamin C from food and beverages are 105.2 mg/day for adult men.)
Excess vitamin C can cause diarrhea, cramps, and nausea because of the osmotic effect of unabsorbed vitamin C in the GI tract. Most of all, exceeding 2,000 milligrams can do the opposite of what you intended to do. “Taking too much can lead to immune-system suppression,” says Ryan Andrews, RD, registered dietitian at Precision Nutrition and an adjunct instructor at Purchase College.
Do You Need to Take a Vitamin C Supplement?
NOT REALLY. MOST guys reach their daily vitamin C requirements through food alone. Whole foods are also full of other healthy nutrients that work synergistically with C, producing more benefits than the vitamin can alone.
Citrus fruits and veggies are your best sources for vitamin C. Tomatoes and potatoes—staples of the American diet—are also rich in vitamin C along with Brussels sprouts, red and green peppers, and strawberries. Even some breakfast cereals are fortified with vitamin C. If you eat one large orange and 1 ½ cups of cooked broccoli, you’ve hit your 200 to 400 milligram recommendation for the day.
Now if you’re someone who doesn’t eat any of the above or have a condition that puts you at risk of a vitamin C deficiency, then maybe it’s worth a conversation with your doctor about a supplement.
This article originally appeared in the December 2020 issue of Men’s Health and has been updated.
Jocelyn Solis-Moreira, MS is the associate health & fitness for Men’s Health and has previously written for CNN, Scientific American, Popular Science, and National Geographic before joining the brand. When she’s not working, she’s doing circus arts or working towards the perfect pull-up.
Cassie Shortsleeve is a skilled freelance journalist with more than a decade of experience reporting for some of the nation’s largest print and digital publications, including Women’s Health, Parents, What to Expect, The Washington Post, and others. She is also the founder of the digital motherhood support platform Dear Sunday Motherhood and a co-founder of the newsletter Two Truths Motherhood and the maternal rights non-profit Chamber of Mothers. She is a mom to three daughters and lives in the Boston suburbs.
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