When you stroll down the cold and flu aisle in a drugstore, it’s easy to get lost in the dizzying array of products promising to clear sinus pressure, dry up sniffles and stop plaguing coughs. Some concoctions even offer it all in one magical pill.
But doctors say the science behind some of those claims is lackluster.
“There’s just not much that’s very effective for treating the common cold,” said Dr. Lauren Eggert, clinical assistant professor in the Pulmonary Allergy and Critical Care Division at Stanford University.
“Most of the things out there — antihistamines, decongestants, cough medicines — none of them have a lot of evidence that they’re super effective at improving cough or common cold symptoms.”
Headlines blasted that message in September when advisers to the FDA found oral phenylephrine, which is an active ingredient in some Sudafed, Mucinex, and Dayquil products, is simply not effective. The review was prompted by inquiries dating back nearly a decade.
Shortages of certain vitamins and minerals cause your immune system to be weaker. Low zinc is one but vitamin d, k, b12 and (less than made out by marketing but not zero) C deficiencies make you more susceptible
This is the main thing with supplements in general. If you’re deficient and the supplement is in a bioavailable form then it will help you (though not necessarily with the specific issue you want to resolve, and with illness it’s better to be prepared ahead of time rather than try to catch up once you’re sick). If you aren’t deficient, you’re just giving your kidneys more work for no benefit.
And this is just speculation, but viruses and bacteria also use vitamins and minerals to replicate, so it’s possible that certain supplements could benefit the infection. That said, your cells vastly outnumber infection cells unless you’re doing very badly already, so odds are your body still gets more benefit from not being out of something, even if the virus needs it.