Vitamin C

Last updated: January 13, 2017


Lauded as the greatest gift to anyone with the common cold, vitamin C is an essential nutrient with antioxidant properties. While scientific evidence does not favor vitamin C as the be-all-end-all for illness prevention, evidence suggests it can reduce the duration of the common cold by 8 – 14% [1].

Beyond marginal benefits for the common cold, vitamin C can increase blood flow [2], increase oxidation (as an antioxidant) [3], and decreases feelings of fatigue [4]. For the brain, vitamin C is involved in many enzymatic actions that influence aspects of cognition, such as neuroprotection [5]. Because of the vitamin’s role as an antioxidant, there is evidence to suggest adequate vitamin C can help prevent dementia and even Alzheimer’s disease [6][7].

Also Known As

Ascorbic Acid, Ascorbate, 2-oxo-L-threo-hexono-1, 4-lactone-2, 3-enediol, L-ascorbic acid

Editors’ Thoughts on Vitamin C

Like most people, my experience with vitamin C started with parents forcing me to take the supplements to avoid illness. As a competitive athlete putting a lot of stress on my body, I’m now glad that they did. It seems the evidence validates vitamin C as a potent immune booster for athletes specifically even if not the general population.

More recently, I use it once I notice I am getting sick or before journeys to stressful climates (including recent trips to Iceland or New Mexico for skiing).

My only word of caution is to make sure you buy vitamin C that is sugar free. The last thing you want to do is take a bunch of vitamin C for your immune system with a bunch of sugar that (generally) hurts your immune system.

Mansal Denton, Nootropedia Editor

vitamin c

Benefits of Vitamin C

The enzymatic actions involved with vitamin C are many and highly important for adequate cognitive function. Specifically, vitamin C is an enzymatic cofactor for an enzyme called dopamine beta-hydroxylase, which helps to optimize production of major focus and concentration hormones like dopamine, adrenaline, and noradrenaline [8].

Even though vitamin C supplementation may not increase these hormones directly (due to rate-limiting steps in the brain), they are nonetheless important. The same can be said for hormones like oxytocin and vasopressin, which may be why vitamin C shows marked increases in sexual activity (at 3000 mg dose) [9].

Other benefits of vitamin C include neuroprotection via antioxidant mechanisms. In one rat study, vitamin C was able to reduce oxidative and inflammatory markers that often cause dementia and Alzheimer’s disease [10]. To achieve this, not only does vitamin C bind with free radicals (antioxidant effect), but it also increases the production of other antioxidant enzymes [11].

Of course, as your parents might have suggested, vitamin C can also be used for improving immune health and preventing colds. As mentioned above, extensive meta-analyses in the 2013 Cochrane Database of Systematic Reviews, found that vitamin C did not reduce the incidence of colds in 11,306 participants [12].

However, those who took vitamin C after contracting a cold saw a 8 – 14% reduction in the recovery time necessary. It seems athletes have an even greater advantage when using vitamin C to prevent illness because their body is already under stress.

Side Effects of Vitamin C

The most common side effect of vitamin C is diarrhea and gastrointestinal distress. This is often caused when taking high doses of vitamin C above 500 mg because of the relatively poor absorption beyond this quantity [13].

Many vitamin C products (including common, household names) are well beyond the 500 mg threshold. Most vitamin C is absorbed at levels around 100 – 500 mg and anything in excess creates the gastrointestinal distress.

Vitamin C Dosage

The standard vitamin C dosage (recommended daily intake) is 1-200 mg per day. Usually this is attained through diet, but many people still supplement vitamin C elsewhere. Up to 2000 mg can be used during bouts of illness (or for athletes to prevent illness).

How and Where to Buy Vitamin C

Vitamin C is an easily sourced nutrient from your local food or grocery store. Most of the vitamin C for sale is in the form of ascorbic acid, but make sure that you purchase a product that  is free from excess sugar and additional ingredients.

If you are not consuming another product that has vitamin C (such as Qualia), then we suggest you look for a basic alternative such as this.

References (Click to Expand)


Nootropedia provides research-driven and accessible nootropics information. Don’t be in the dark about nootropics.