Many people swear by immune system supplements like Emergen-C and Airborne to ward off colds and bolster them for germ traps like airplanes.
The little chalk tablets are chocked full of nutrients and ingredients with names that sound like biochemical wizardry - some of which are dietary components needed to maintain immune system health.
But, ultimately, it's just a multivitamin in fizzy form, and studies have found that taking it may shorten your cold - but it's unlikely to keep you from catching one.
Daily Mail Online breaks down the ingredients that make up Emergen-C - and why none of them are likely to stop you from catching a cold this winter.
Emergen-C and other immune system-boosting tablets contain many vitamins associated with the immune system, but studies show they at best shorten colds - but don't prevent them
WHAT EXACTLY IS THE COMMON COLD, AND HOW DO WE FIGHT IT BETTER?
To understand how to fight off a cold, we first have to know what we and Emergen-C are up against.
Over 200 kinds of viruses can cause the loose web of symptoms - congestion, runny nose, coughing, sneezing and sometimes a fever - that we call the common cold.
When the body detects an invading virus, antibodies rush to the virus cells, halting their ability to multiply and tagging them to make them recognizable to white blood cells, which come to try to diffuse, expel and try to memorize the identity of the virus, in case it should ever come back.
These are all functions of the immune system, so having a strong one is crucial to fighting off infection.
Poor nutrition and nutrient deficiences will certainly hamper the immune system's functioning, but it is made up of many complex components.
So even if you do boost your levels of nutrients key to maintaining your immune system, there is no proof that doing so will make an adult's body fight off a virus that is already attacking you.
There are many different cell types involved in the immune system, and the best 'diet' for one type is not necessarily right for the others and we just don't have the whole equation for nutrition and optimal immunity worked out fully.
So, while the laundry list of vitamins nutrients and other substances an Emergen-C tablet may be linked to immune system health, chugging a glass of them is not a direct boost to overall immunity.
WHAT ARE THE MAIN NUTRIENTS IN EMERGEN-C - AND WHAT DO THEY HAVE TO DO WITH FIGHTING A COLD?
1. VITAMIN C - 250MG
Vitamin C is is food to several different kinds of immunity cells, including T cells, which (in their various sub-forms) can spot a foreign body, turn on fighter cells and
