Vitamin C supplements may not be best for your cold

Americans spent more than a billion dollars on vitamin C supplements last year. It may seem like a good idea to take an extra boost when you've got a cold, but Consumer Reports says that could be a mistake.

The problem is, you may already be 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," said Lauren Cooper from Consumer Reports.

And taking vitamin C supplements won't prevent a cold in the first place, according to the National Institutes of Health.

Taking high doses of vitamin C can also cause other health problems.

For example, 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 an upset stomach and painful cramps.

In general, the NIH recommends 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," said Cooper.

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

As for that 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 if you'd like, pick up a good humidifier.

Be aware that vitamin C supplements may interact or interfere with certain kinds of treatments and drugs, according to the NIH.

That includes chemotherapy and heart medication. It's best to always check with your doctor before taking any dietary supplements.