Zinc for Colds?

If Vitamin C is not the answer to prevention or treatment of colds, what about zinc? Around 25 years ago, studies showed that zinc lozenges could significantly reduce the duration of the common cold. Since that time, the medical literature has been conflicting, with roughly half of the studies showing benefit, and half appearing equal to placebo.

Zinc nasal preparations were then released, but in 2009, the FDA issued a warning that these intranasal zinc preparations had the potential to cause permanent loss of smell, so they are no longer recommended.

It turns out that you need to have ionic zinc in the lozenges to be effective, and the vast majority of products out there do not have this type of zinc. Taking zinc supplements in pill form doesn't work either, so don't be fooled into swallowing yet another pill.

What DOES work? Well, the best prevention is what your mom most likely taught you growing up: WASH YOUR HANDS! It doesn't matter if you use the hand sanitizer or old-fashioned soap and water, but whatever you use, scrub for 20 to 30 seconds, and try not to touch your face or eyes.

BOTTOM LINE: If you are going to use zinc to try to shorten the duration of your cold, get an ionic zinc lozenge preparation. More importantly, however, WASH YOUR HANDS!

Vitamin C for Colds?

Okay, since I talked again about vitamin D last week, why not talk about a few more vitamins? What about Vitamin C for colds? Should it be taken as prevention, or as a cure? Can you get too much?


Honestly, the medical literature has gone back and forth on vitamin C and colds. Large studies have shown little benefit in prevention, unless you are an extreme athlete or living in very cold temperatures. For people in those categories, it appears Vitamin C in doses greater than 200mg per day can indeed decrease the frequency of upper respiratory infections. Skiers, perhaps you should start your morning with a big glass of juice instead of hot chocolate or coffee!

Where there does seem to be benefit across the board is when Vitamin C (again in doses greater than 200mg per day) is taken once you develop cold symptoms. At that point, Vitamin C seems to decrease the duration of symptoms.

How much is too much? The RDA is 75mg for women and 90mg for men. Supplements come in 100, 200 and 500mg tablets, plus I'm sure you've seen and maybe taken the mega-dose vitamin C packets that come in powder packets. These typically have 1000mg of Vitamin C (along with a handful of other vitamins). While C is water-soluble, which means that "extra" vitamin C not used by your body will simply exit in your urine, it is possible for megadoses (often exceding 2000mg per day) to cause kidney damage by precipitating a special type of stone formation in the kidneys.

What type of Vitamin C is best? As always, you are better off getting your vitamin C from whole foods-fruits like berries, red peppers, guavas, kiwis, and yes, oranges. You will NOT overdose from these natural sources!

BOTTOM LINE: Vitamin C may help shorten the duration of a cold, and could help with prevention for those in cold climates or if you will be doing "extreme" physical activity.