Back in 1970, Nobel Prizewinner Linus Pauling made headlines when he said large amounts of vitamin C could cure or prevent the common cold.

It was probably the first introduction most Americans had to “alternative” medicine, especially the supplement side of it. Now millions of people take all kinds of supplements. Back then it was a new thing.

It turns out that vitamin C — the first and perhaps the cheapest medicinal supplement – is also good for your brain. As far as that goes, this vital antioxidant helps protect every part of the body from harmful oxidation.

Without it you’d be literally lost – your brain wouldn’t even work well enough to guide you around the block without losing your way.

A wealth of research now shows how this nutrient is crucial for enabling your brain to cope with life in a complicated world. And those studies also demonstrate that the brain is especially needy and greedy when it comes to vitamin C.

Here’s an example of what I mean. . .

When the human body starts to run out of vitamin C and you aren’t consuming enough, it will vanish from every other organ before your body will allow its removal from your brain. Your brain is the last place to give up this precious nutrient.

That’s how important it is to brain health – and to your very survival.

A Neuron’s Best Friend

If you wrote up a list of the brain processes that require vitamin C to function, it would include just about everything the brain has to do to keep your memory intact and your daily life on track.

Vitamin C plays a key role in –

  • Making new neurons from stem cells – processes called neuronal differentiation and maturation.
  • Coating neurons with the myelin sheaths that protect them and help transmit information to the brain’s neural networks.
  • Regulating the system of nerve cells (called the cholinergic system) that reinforces your memory and helps you learn new knowledge.
  • Supporting the brain’s glutaminergic system – the neuronal system that’s central for retrieving memories.

So it’s no surprise that when Australian researchers reviewed almost 40 years of research into the brain’s endless thirst for vitamin C, they found substantial evidence that the level of vitamin C in your blood directly correlates with your mental powers.1

However, these researchers also sounded a note of caution:  Among people who are already suffering serious memory and cognition problems, the studies they reviewed did not find that consuming more vitamin C or, at that point, having more vitamin C in the blood improved a person’s mental abilities.

Sad to say, it seems that once you reach the tipping point of developing Alzheimer’s disease or another serious neurodegenerative condition, upping your vitamin C intake to save your recall abilities doesn’t seem to work.2

You have to maintain adequate vitamin C during your entire life. Take that lesson on board. It’s an important one.

Peeking Through the Blood/Brain Barrier

The brain is able to stubbornly hold on to its supply of vitamin C because the blood/brain barrier enables vitamin C to enter brain tissue from the blood but, when the barrier is working correctly, it keeps vitamin C from leaving.3

Once it’s in the brain, vitamin C stays busy offering antioxidant protection for neurons as well as taking part in the processes that keep the neurons working properly.

Now, although studies have not found that giving doses of vitamin C to people who already have Alzheimer’s is any help, researchers do know that vitamin C performs tasks that are appropriate for helping prevent Alzheimer’s –

  • It chelates and captures the minerals copper, iron and zinc which could otherwise bind to the amyloid plaque that accumulates when you develop Alzheimer’s. Left to their own devices, these minerals can also lead to the formation of harmful substances called advanced glycation end products (AGEs).4Sidebar comment: Few people need to supplement with iron and copper and you should take these minerals in pill form only if confirmed by a blood test and an expert nutritionist. Most people DO need to supplement with zinc, but, again, it’s best to do it under the guidance of an expert. And the amount you need is usually small – 25 mg a day is adequate for most people. Meanwhile, taking vitamin C will help ensure your body doesn’t accumulate too much of these minerals.
  • Vitamin C’s antioxidant activity reduces the development of lesions in the brain that can cause neurons to malfunction.5
  • It helps limit inflammation in the brain.6

Of course, vitamin C doesn’t function in a vacuum. Most of the research I’ve seen points to the fact that eating plenty of fruits and vegetables may add to vitamin C’s ability to protect the brain. And a study in the Netherlands that involved more than 5,000 people found that vitamin E together with vitamin C produces a “lower risk of Alzheimer’s disease.”7

How Much do You Need?

When it comes to the question of how much vitamin C you need for optimal brain function, the jury is still out. A New Zealand study of brain health in 50-year-olds showed that getting around 110 mg a day of vitamin C didn’t seem to be enough to insure an adequate level in the body.8

The recommended daily amount in the US is 90 mg for men and 75 mg for women,9 which is obviously too low to keep your brain well-supplied. And while the Federal Office of Dietary Supplements says you shouldn’t take more than 2,000 mg a day, few people who really know anything about nutrition would agree. There seems to be little – if any – evidence that taking much, much more than that will do you any harm.

The only bad side effect I’ve ever heard from vitamin C is some gastrointestinal distress. Apparently diarrhea sets in for most people if they take around 10 grams (10,000 mg) a day by mouth. People take much greater amounts than that by IV – bypassing the GI tract problem – and in fact this is a powerful cancer treatment.

For the record, I take 2,000 mg per day in supplement form, plus whatever I’m getting in the food I eat, which is probably pretty large.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5622720/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5622720/
  3. https://dm5migu4zj3pb.cloudfront.net/manuscripts/119000/119832/cache/119832.1-20140626150553-covered-253bed37ca4c1ab43d105aefdf7b5536.pdf
  4. https://www.ncbi.nlm.nih.gov/pubmed/20730621/
  5. https://www.ncbi.nlm.nih.gov/pubmed/22888398/
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3725125/
  7. https://www.ncbi.nlm.nih.gov/pubmed/12076218/
  8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579624/
  9. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/