How "safe" are supplements?_00000711.jpg
How safe are supplements?
02:58 - Source: CNN

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The myth of vitamin C preventing the common cold began back in the 1960s and 1970s

More than 2,000 mg per day can cause nausea, diarrhea and stomach cramps

Taking vitamin C is associated with slightly shorter illnesses

When you feel the sniffles coming on, you should reach for the OJ, right? Not so fast! We asked the experts whether this was an old wives’ tale, or actually sound advice. The verdict: “For most people, taking vitamin C supplements regularly does not reduce the risk of coming down with a cold,” says Carol Haggans, MS, RD, a Scientific and Health Communications Consultant for the NIH’s Office of Dietary Supplements.

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Yet, vitamin C does still play an essential role in supporting your immune system, according to research. And under certain circumstances, it could be beneficial for you, says Haggans.

Confused much? Here’s what’s really going on with your body and the benefits of vitamin C.

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The Legend of Vitamin C

The myth of vitamin C preventing the common cold began back in the 1960s and 1970s when a renowned scientist named Linus Pauling discovered that mega-doses of vitamin C allegedly prevented him from catching a cold for years. According to The Atlantic, “Pauling believed that the common cold would soon be a historical footnote.” Pauling published a best-selling book, and his cold-busting recommendation quickly became common knowledge — though research both before and since has repeatedly refuted Pauling’s claims.

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According to the NIH, “Overall, the evidence to date suggests that regular intakes of vitamin C at doses of at least 200 mg per day do not reduce the incidence of the common cold in the general population.” Taking vitamin C regularly also doesn’t reduce the severity of a cold. Moreover, taking too much vitamin C can cause problems. “Like most vitamins and minerals, vitamin C does have an upper limit,” Haggans notes. More than 2,000 mg per day can cause nausea, diarrhea and stomach cramps.

The Real Benefits of Vitamin C

It’s not all bad news if you’re popping vitamin C supplements. While vitamin C is unlikely to impact whether you get sick or how sick you get, taking vitamin C is associated with slightly shorter illnesses. Researchers found that preventive vitamin C supplementation was associated with colds that were eight percent shorter in adults and 14 percent shorter in kids.

There are a couple other notable exceptions to the “vitamin C doesn’t prevent colds” rule. “For some people, such as marathon runners, skiers and those in the military…[vitamin C] does seem to help reduce the chances of getting a cold,” says Haggans. Those who are under extreme exercise or weather conditions (which could compromise your immune system) may see a benefit from taking between 250 and 1,000 mg of vitamin C, she says.

And while taking extra vitamin C might not help the average person, it is important to meet your recommended daily intake in order to keep your immune system firing on all cylinders. “Vitamin C supplements might also help people with marginal vitamin C intakes, such as elderly people and chronic smokers,” says Haggans. Smokers and those regularly exposed to secondhand smoke have lower levels of vitamin C. Smokers often consume fewer fruits and veggies — and both firsthand and secondhand smoke causes oxidative stress in the body, according to the Institute of Medicine.

There’s an important caveat for all of these populations, though. Positive effects are only seen when taking vitamin C supplements preventively; it’s too late to jump on the bandwagon once you feel that tickle at the back of your throat. Researchers haven’t found any evidence that vitamin C helps kick a cold once you’ve caught it, says Haggans.

Are You Getting Enough Vitamin C?

Fortunately, most of us don’t need to worry about taking extra C — most Americans get plenty, says Haggans. The recommended daily intake is 75 mg for women and 90 mg for men, meaning you’d get more than enough from a six-ounce glass of orange juice or a cup of steamed broccoli, she adds.

Plus, your body seems to like getting its nutrients from real food, as opposed to pills. “A lot of research shows that people who consume high amounts of fruits and vegetables, which are packed with vitamins and minerals, have a lower risk of getting cancer and heart disease,” Haggans says. “But taking the vitamins and minerals separately via dietary supplements doesn’t seem to have the same benefit.”

While you should certainly check with your doctor about any supplements you take or wish to take, maintaining a healthy diet may be your best bet for staying healthy throughout this cold season — and for years to come.

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