Vitamin C might actually do more harm than good when you’re sick.

If you’re looking for ways to clear up sniffles and sneezing, think twice before loading up on Vitamin C supplements. By that time you’re likely too late.

“There is some evidence that shows taking a daily dose of vitamin C supplement on a regular basis while you’re still healthy might shorten your cold by a day or so. But starting a vitamin C supplement once you’re already sick really won’t help, ” says Lauren Cooper from Consumer Reports. 

And many health experts say taking vitamin C supplements won’t prevent a cold in the first place.

Taking high doses of vitamin C can also cause other health problems. Studies have shown that men who take excessive amounts are twice as likely to develop kidney stones and consuming more than 2,000 milligrams of vitamin C a day can cause upset stomach and painful cramps. The Dieticians of Canada recommend 90 milligrams per day for men and 75 milligrams a day for women for maintaining good health. That’s about the equivalent of a single orange.

“The best way to get the vitamin C you need is the old fashioned way, from fruits and vegetables,” recommends Cooper. 

Some of the best foods for vitamin C include red and green peppers, citrus fruits, kiwi and broccoli. 

As for the cold, forget the quick fix. If you need some relief from your symptoms, choose over the counter medications like Ibuprofen or Acetaminophen for aches and fever. Or single ingredient decongestants. To help your cough, try throat lozenges or honey and of course, get plenty of rest, drink lots of fluids and maybe pick up a good humidifier.

And healthcare professionals warn that vitamin C supplements may interact or interfere with certain kinds of treatments and drugs. That includes chemotherapy and heart medication, so it’s always best to check with your doctor before taking any dietary supplements.