The advice to take mega doses of vitamin C to stave off illness, or even to cure illness, has been around since Nobel Prize-winning chemist Linus Pauling popularized it in the 1960s. It is stored in the medicine cabinets of households across the nation, and people who suddenly find themselves coming down with a cough or sneeze regularly reach for the vitamin C tablets well before they reach for anything else. But more and more scientists are coming to the conclusion that the vitamin may not actually deliver any immunity-boosting power at all.

Make no mistake, vitamin C plays a vital role in maintaining health. It is a powerful antioxidant, which works to absorb free radicals inside the body, thereby minimizing the amount of oxidative stress and damage that the free radicals can wreak, and also lowering the chances of an individual developing cancer. In addition, it prevents people from developing scurvy, which is a condition caused by a lack of vitamin C and leads to bleeding from the gums, the loss of teeth, and open wounds. But a miracle cold cure the vitamin is not. Upping the dosage of vitamin C from the recommended 75 milligrams for women and 90 milligrams for men to the mega-vitamin dosage of 1,000 milligrams also does not increase the powers of the vitamin, according to Dr. Andrew Weil, a professor at the University of Arizona who has written on health and nutrition, National Public Radio reported. This is because though vitamin C is essential for normal tissue function, a typical human body cannot even process and use more than 200 milligrams of the vitamin each day, meaning that when you take a 1,000-milligram vitamin C supplement, your body is only using 200 milligrams at most. This means that the other 800 milligrams are going to waste – literally. Whatever the body does not use, it ends up excreting in human waste.

In addition, vitamin C supplements can be even more ineffective because the body does not absorb the synthetic vitamin as easily and efficiently as it does absorb the vitamin from actual foods. So while a mega dose of vitamin C in the form of a supplement is not going to be harmful, it also is not a cure-all for sneezing fits or coughs. The best way to prevent a cold and boost your immune system is to eat a healthy diet, including foods that are rich in vitamin C.