Yes, and no.
Vitamin C is very important to supporting a healthy immune system but it is not a “Star Wars” like defense system, warding off aliens and invaders such as pathogens, harmful bacteria, viruses and such.
In and by itself, Vitamin C is not going to fend off the flu and viruses. And it is certainly very unlikely to provide a protective defense against the new, as well as the older, corona virus.
In short, its presence does not give an immune shield by itself. It is better thought of as supporting your body’s defense systems than as a weapon. A good comparison is thinking of your immune system as a boxer or fighter, while Vitamin C is a part of the nutritional program that keeps that fighter strong and full of "keep on fighting" power!
So yes, it does help support your immune system and so should very much be a part of your ongoing health regimen.
Granted, taking vitamin C can help to shorten a cold’s duration by about 8%, at least for the general population. There are studies done on individuals in very high physical stress situations (such as long-distance runners and Arctic explorers) where doses of vitamin C appeared effective in significantly reducing the likelihood of a cold or flu, but few of us are ever under that level of physical strain.
The point here is that the regular supplementation of vitamin C is the effective route to warding off colds and flu, much more so than the practice of “flu-bombing.”
And, as a note, while rumors abound of Chinese doctors curing COVID-19 patients with massive doses of vitamin C, the truth is that this is only one treatment path being explored amongst many. Hopefully by September of 2020, they will have the clinical outcome of these trials and perhaps there will be positive results. But in the meantime, there is little if any proof that vitamin C could ward off COVID-19 or work as an effective treatment.
Research does not support the idea that Vitamin C, by itself, will protect against colds and the flu. But it does provide vital support to the system that does job–your immune system. Here are some of the ways it does that:
In other words, the body utilizes vitamin C in many of its protective systems and especially in the functions of the immune system.
You probably already know that white blood cells are an important part of your immune system. They patrol the body and respond to the presence of “antigens” and go into attack mode to clear these away. (Antigens are just things like bacteria, viruses, cancer cells and so forth–basically harmful invaders that provoke an immune response)
The most common type of white blood cell is called a “neutrophils” and these guys are the white blood cells troopers that lead most of the immune attacks against the antigens, think of them as the “first responders” to an infection or injury. The neutrophils are able to travel pretty much throughout the body and are key to a healthy and effective immune system.
Well, guess what… studies show that neutrophils contain high concentrations of vitamin C and so it is thought that this is one of the mechanisms behind vitamin C and enhanced immune function–more Vitamin C equals more neutrophils. (For more information see this Study Supporting Vitamin C and Enhanced Immune Function)
The point is that a powerful, functioning immune system is critical to fighting off colds and other ills. It is your best protective shield. Simply taking Vitamin C when you are sick, or feeling under the weather, is not your most effective strategy. It is like waiting to repair the defensive walls only when you see the enemy charging.
The time to build a strong immune system is BEFORE the invaders attack. That way your body can ward them off before they become a problem. And, if they do “breach the walls” then a strong immune system is likely to knock them out before any serious damage is done.
The big takeaway here is to eat a varied diet (lots of dark green vegetables and a moderate intake of fruits, kiwis and citruses are especially good). And to supplement with a quality Vitamin C supplement, the timed-release types are generally best for regular use.
It is important to understand that Vitamin C supplements are a great idea and should be a part of your diet. BUT they are called “supplement” as they are intended to supplement (add to) an already healthy and varied diet. There are tons of references on good sources of Vitamin C, just be sure to load your diet up with these and other superfoods.