Does Vitamin C Really Help When You’re Sick?
Vitamin C has almost legendary status among pharmacy supplements. We usually take a few pills when we’re afraid of getting sick, or mix up a glass of Emergen-C at the first sign of a cold. It’s nice to present this as a panacea, but the reality doesn’t quite live up to our hopes.
Vitamin C probably wouldn’t be what it is today if Nobel laureate Linus Pauling wasn’t really excited about it . (His enthusiasm was, ironically, contagious.) But even today, the Linus Pauling Institute at Oregon State University writes: “Vitamin C is widely believed to enhance immune function, but published human studies to date are inconsistent.”
When Vitamin C (Rarely) Helps
As we noted in a previous post about immune-boosting supplements, the proven benefits of vitamin C are small and probably not applicable to most of us. People who experience extreme stress due to extreme exercise (such as marathon runners and soldiers training in subarctic conditions) may be less likely to catch a cold if they take vitamin C.
Several studies have shown that people who regularly take large amounts of vitamin C may experience colds slightly shorter (recovering a day or half a day sooner), but the vitamin does not prevent them from getting sick in the first place. However, a 2013 Cochrane review concluded that the evidence is mixed, and even short-term colds are not reliably observed in studies.
The National Institutes of Health summarizes the study as follows:
Overall, current evidence suggests that regular intake of vitamin C at a dose of at least 200 mg/day does not reduce the incidence of colds in the general population, but it may be beneficial for people exposed to extreme exercise or cold conditions and people with marginal vitamin C status, such as the elderly and chronic smokers.
Extra Vitamin C Won’t Help You Recover
“Taking supplements after cold symptoms have already begun has no proven benefit,” says the Linus Pauling Institute. If you already have a cold, the opportunity may have been lost to shorten the duration of your cold.
The institute’s information page on vitamin C provides research on other diseases and I would recommend reading it if you want to learn more. People who regularly get enough vitamin C have a lower risk of developing certain diseases, including heart disease.
Luckily, vitamin C is quite common in fruits and vegetables, and if you eat a healthy diet, you probably won’t have trouble meeting your needs. If you want to play it safe by taking it in tablet or powder form, there aren’t many downsides. High doses can sometimes cause diarrhea, but studies have not found any long-term or serious effects from taking large doses of the vitamin. However, caution is advised: a maximum of 2000 mg per day is considered a safe upper limit .
What to take instead of vitamin C
As soon as you start to feel a scratchy throat, don’t take Emergen-C or Airborne —unless it’s your personal ritual that makes you feel better (go ahead, use the placebo effect ).
What should I stock up on instead? Honey is one of the most effective cough syrups . If you need something to help relieve your nasal congestion, take your ID with you and buy pseudoephedrine, a drug commonly sold over the counter. (Its standard substitute, phenylephrine, often sold as “Sudafed PE” or under other names, simply doesn’t work .) Clearing your sinuses with a neti pot (for adults), a bulb syringe, or a NoseFrida (for small children) may also help. .
Make sure you drink plenty of fluids, get as much sleep as possible, and clear your schedule of anything stressful that can be put off until later. You may still get sick, but at least you’re doing your best to minimize the extra stress on your body. Your immune system can take good care of you if you let it. And you don’t need extra vitamin C for this.