Linus Pauling is widely regarded as one of the fathers—if not the father—of molecular biology. He helped discover the nature of chemical bonds, identified sickle cell anemia as a molecular disease, elucidated some of the most common protein structures, revolutionized our understanding of primate evolution, and is widely regarded as one of, if not the father, of molecular biology.
Oh, and he almost single-handedly disseminated one of the most enduring medical myths: that vitamin C prevents colds.
It all started with quackery, just as the much more harmful misconception that vaccines cause autism. Pauling initially learned about vitamin C’s wonders (or lack thereof) from a man named “Dr.” Stone, who was a doctor in the same manner that a koala bear is a bear—that is, he wasn’t. But darned if it wasn’t enough to convince Pauling that 3000 milligrams of vitamin C would cure just about any ailment imaginable.
He and Stone devised a poor clinical trial that purported to illustrate their thesis, but other researchers pointed out had a major flaw: the persons who were given vitamin C were healthier, to begin with, so they naturally had better outcomes. Pauling, on the other hand, was unfazed. The American audience went crazy about his book Vitamin C and the Common Cold, which he published in 1970. After all, here was a man so brilliant that he was (and still is) the first person to ever receive two Nobel Prizes in unrelated subjects, and one of only two persons to earn Nobel Prizes in two fields (chemistry and peace). He’s got to know what he’s talking about, right?
Pauling went on to say that high doses of the supplement may treat everything from heart disease to leprosy to cancer. And the general public was willing to pay for it. Even though every professional medical body in the world dismissed the theory as unfounded, here was a Very Smart Man advising the good people of the Earth that taking vitamin supplements will fix all of their health problems.
The problem is that vitamin C does not prevent colds or cancer, nor does it cure either disease. According to certain studies, regular use may lessen the length of a cold, but not when taken after it has begun. Others have discovered links between higher daily dosages and a lower risk of cardiovascular disease, while others have found no link at all. Cataracts, pneumonia, tetanus, asthma, and liver disease are all examples of this.
In terms of cancer, the highest-quality evidence suggests that taking vitamin C supplements does not influence your risk of developing cancer or the outcome of cancer once you have it. It may improve the efficacy of some therapies, but it’s also plausible that it hinders the efficacy of others. While some tiny studies have shown that exceptionally high doses of vitamin A can destroy cancer cells, this is only true when the vitamin is administered intravenously. Oral supplements cannot significantly boost the quantity of vitamin C in your plasma, however direct injections can.
Linus Pauling died of prostate cancer in 1994, while his wife died of stomach cancer a few years before.
The bottom line is that taking vitamin C pills will almost certainly have no impact on your health. Because it’s a water-soluble vitamin, whatever extra you consume will be expelled from your urine. The biggest danger is that you’ll suffer diarrhea or other gastrointestinal disorders (provided you don’t have genetic hemochromatosis, or iron excess, which can lead to long-term harm to your internal organs).
Taking vitamin C daily is unlikely to harm you, but you almost certainly do not require it. It’s simple to consume enough without taking tablets. Oranges, garlic, strawberries, chili peppers, kiwi, beef liver, oysters, guava, broccoli, parsley, onion, peach, apples, pears, carrots, bananas, avocados, plums, and a whole host of additional foods that you may not be aware of or have never heard of containing vitamin C. (see: Camu Camu, seabuckthorn, and cloudberries).
Having said that, if you have a vitamin C deficit, you should take supplements immediately. Scurvy is no laughing matter, as any 18th-century sailor will tell you. Even if it doesn’t go that far, vitamin C is required for collagen production, wound healing, neurotransmitter production, and immune system support. Most people get enough from their diets, although inadequacies remain in persons who eat junk food nearly exclusively in industrialized countries. Aside from that, the problem has mostly vanished now that the general public has frequent access to a variety of fruits and vegetables.
So, like practically all vitamins, vitamin C isn’t necessary unless you have a serious deficit. Which you most likely don’t. Consider this your permission to quit buying cold treatments that are laced with megadoses of vitamin C and fake orange flavor in an attempt to fool you into believing they’re tasty. Just eat a regular orange and you’ll be fine.