To the average Joe, massive vitamin C doses are undoubtedly the first words that spring to mind when hearing “common cold”. Natural health enthusiasts argue that flooding your body with vitamin C is a shield against cancer and heart disease. Every winter, as the first clouds of green-coloured flu stalk the streets, people dash to the shops to buy vitamin C gummy bears, beverages and giant unswallowable pills.
Health authorities, meanwhile, disagree vehemently. The European Union recommends only 110mg for men and 95mg for women, while India recommends 40mg for both. Denmark, Iceland, Finland, Norway and Sweden all recommend 75mg for both sexes (agreed by a Nordic council, which is much duller than it sounds) while Australia and New Zealand have 45mg for both. Most multivitamins stick rigidly to the 60-100mg mark.
So who’s right? Most importantly, could it affect your noble quest to vanquish acne from the land? Vitamin C affects your skin by 1) acting as an antioxidant, 2) lowering stress hormones, and 3) helping to construct your skin’s collagen.
The fact is that today’s vitamin C recommendations are a relic from another era.
The scurvy connection
To really understand the situation today you have to travel back 500 years, to the era of scurvy. It was caused by extreme vitamin C deficiency, although nobody knew it.
Scurvy was so common on naval voyages that it was a vital deciding factor in warfare. The first symptom was extreme lethargy. Slowly, your gums would become sensitive, before vast gangrenous areas of the skin appeared due to internal haemorrhaging. Due to shortages of manpower, one bumbling 1700s expedition used 70 year old veterans plucked from a military hospital; they were horrified as wounds from 50 years ago reopened. Long ago broken bones would separate as though never healed. Death would come from a haemorrhaging of the heart or brain.
Scurvy is almost non-existent now, but like cancer today, the mere word would strike cold fear into the hearts of 18th century sailors. It was the phantom killer, a mystery illness. For all sailors knew, it could have been a deadly waterborne bacteria. It could have been a mysterious Atlantic whale species with a cursed glance. The “putrid theory” of scurvy was common, that in the watery, cramped ships, a “gradually accumulated putrefaction” of moist air, rotten foods and poor exercise was to blame.
Between 1800 and Columbus reaching America, it’s estimated that 2 million sailors succumbed to scurvy. Governments and shipowners organised crews under the assumption that 50% would fall victim.
More people died from scurvy than enemy attack, shipwrecks and storms combined. Sometimes, sailors would stagger onto the shores of a Caribbean island, buy tropical fruits from a local street vendor, and be astonished as they healed rapidly.
In 1733, James Lind accidentally discovered the role of vitamin C. On a creaky wooden shipdeck, he fed 6 scurvy patients either vinegar, vitriol, seawater, a herbal remedy called “electuary”, lemon juice and oranges. Only the lemon and orange patients improved – so rapidly, in fact, that they aided the good doctor with his experiment.
James Lind then wrote a 400 page book, but vitamin C remained undiscovered. Lind still believed in the purification theory, that citrus fruits treated only one portion of a multifaceted disease. 1795 marked the real turnaround, when the Royal Navy were convinced to supply lemon juice bottles to all ships.
Some historians believe that this decision foiled Napoleon’s invasion, but scurvy wasn’t done yet. For example, in the Crimean war of 1853-1856, Florence Nightingale observed people throwing unused cabbage overboard while sailors lay on deck dying. The invention of pasteurisation caused a scurvy epidemic in the American middle classes due to the heat destroying milks’ nutrients.
In 1932, vitamin C was finally isolated and synthesised in a laboratory. The 400 year scurvy pandemic was finally defeated (mostly), but the echoes were still felt in the 20th century. Every new recommendation for vitamin C was made in the shadow of this killer disease.
Its great benefits for the heart, lungs and brain were an afterthought. Preventing scurvy took as little as 15mg, just five big strawberries. Since it’s a fatal disease, they decided to give it a buffer, and after being founded in 1948, the World Health Organisation established a tiny RDA of 45mg, which still stands to this day.
An old mistake
In 1943, the FDA created the original RDA of 75mg for men. This was decreased to 60mg in 1968, and decreased again to 45mg in 1974.
Why? Because of a series of 1960s and 70s studies which are keeping the RDAs low even decades later.
All these experiments did was administer higher and higher doses, and dismiss them as blood levels failed to increase, without considering where the vitamin C ended up. They concluded that the body’s vitamin C pools were “saturated” at intakes of 100mg per day.
They didn’t consider the brain, which contains the deepest vitamin C reserves of the body, stashed in the form of ascorbate. This accumulation is what improves your cognition and staves off the amyloid protein plaques behind Alzheimers.
Then there’s sodium dependant vitamin C transporters (SVCT2), which move the vitamin from the extracellular space to the intracellular space. Extremely dense reserves are bound up in this molecular hiding place, even when your dietary vitamin C is reduced. The adrenal glands are also disproportionately high in vitamin C.
Furthermore, one study only measured total radioactivity in urine. The patients were injected with radioactive vitamin C (perfectly safe, they didn’t grow a third arm) to measure its removal more accurately. Therefore, a big chunk being removed could have easily been by-products rather than intact vitamin C. The radioactivity dosage was also wisely limited, making tracking the vitamin C harder.
Consequently, the 1970s studies grossly underestimated the amount of vitamin C in the body. In 2020, it is accepted fact that bloodstream content or urinary removal is not an accurate biomarker for your dietary needs.
The science has been superseded, but somehow, huge health bodies are still dependent on it. It’s like the war on saturated fat being based on the 7 countries heart study from back in 1960.
Actually, the recommendations were immediately questioned, by a scientist known as Dr E. Ginter. The studies concluded that a 75kg human had bodily reserves of 1500mg, but Ginter revised this upwards three-fold to 4500mg.
The situation isn’t totally grim. China, for example, has a 100mg bare minimum for men, but also a 200mg “proposed intake” – blandly named, but basically the ideal health level. The European Food Safety Authority has now upgraded to 110mg in 2013 (for men), aiming for near saturated bodily pools of vitamin C, focusing on health. They have moved beyond the old outdated studies, and the old scurvy-fearing mindset.
There’s no doubt that 60mg is too low for vitamin C, both for supercharged health and fantastically clear skin. Most scientists agree – it’s the health authorities who are slow to budge.
Clues from the transporters
The debate starts at massive bro science dosages like 1000mg, 2000mg or even 5000mg. Some scientists argue that beyond 200mg, none is absorbed whatsoever, that as a water soluble vitamin, your body will instantly eliminate any excess.
Firstly, some vitamin C is absorbed directly into the bloodstream through capillaries. However, most leaves the intestine via the SVCT1 transporter, which can only carry so much. If you take 1000mg at once, these transporters will be fully saturated. It’s a physical barrier, at a microscopic level. Note that SVCT2 transporters are the intracellular ones we discussed above.
Secondly, this study found that ascorbic acid overload actually downregulates your SVCT1 genes, with RNA expression falling by 77%. The ascorbic acid absorbed into individual transporters also declined. They concluded that “high-dose supplements might not be the most efficient way of increasing the body pool of vitamin C“.
Thus, we have this 1980 study where humans took a single vitamin C dosage with their breakfast. At 1 gram, the absorption rate was 75%, but this declined to 44.0% at 2 grams, before plummeting to 39%, (3g), 28% (4g) and finally 20% (5g). Meanwhile, this study found that at dosages up to 200mg (which, take note, is far beyond most RDAs), almost 100% is absorbed in human beings.
However, there’s an obvious question: what if you spread the dosage out? If you take 500mg in the morning, afternoons and before bed, will the receptors will be downregulated? The answer is probably inbetween, but I’d guess that with expert timing, 1000mg can easily outperform 200mg. Sending a flood at once may be the wrong decision; you have to give the transporters time. It’s no different to a narrow river bursting its banks in a downpour versus the same quantity in a steady rain storm.
Plus, the 1980 study fared well even with a single dosage. For example, one study found that at 1250mg, only 50% is absorbed. It sounds weak, but it still equates to 625mg vs 200mg.
Do megadoses work anyway?
Which brings us to the next question: if a little tactical genius can get those megadoses into your bloodstream, would they even be beneficial? There’s way too many studies to cover, so where better to check than the classic usage: the common cold.
This 2018 meta-analysis looked fantastic, covering 11 studies and concluding that megadoses improved fever, chest pain and chills. The dosages ranged from 500mg to a gigantic 5 grams. Then there’s this 1999 study on respiratory infections. 463 18-32 year olds began by taking six 1000mg doses of vitamin C on day 1, before switching to 3 daily doses of 1000mg. The result: cold and flu symptoms decreased by 85% compared to the placebo group.
In 2001, however, 400 Australians were given 1 gram or 3 grams of vitamin C, or a placebo. It was a double blind study; nobody knew what they were taking. They were asked to record their colds and their frequency over 1.5 years, and reached the disappointing conclusion that “Doses… in excess of 1 g daily taken shortly after onset of a cold did not reduce the duration or severity of cold symptoms“. This ancient 1974 study compared normal doses to megadoses directly. The results were mixed; while the optimal dosage was 250mg in normal times, high doses had a small benefit during sickness. However, jumping from 4 grams to 8 grams reduced the amount of colds significantly.
It’s the same contradictions everywhere, whether for heart disease or cancer. This megadose study found 2 fold reductions in tumours, when grafted onto mice with crippled immune systems. It was theorised that vitamin C produces hydrogen peroxide (H2O2), which targets cancer cells but ignores normal cells; the more the merrier. But these scientists criticised the result, saying that real life tumours weren’t comparable and the benefit was minuscule compared to chemotherapy (I’d say that if such a simple vitamin has even small benefits, then fantastic). Cancer is particularly relevant to acne because a major culprit is oxidative stress, when free radicals run wild.
How stress increases your needs
However, one factor everyone ignores is stress. They often consider vitamin C for normal people, while ignoring that it’s fairly “normal” these days to smoke, be obese, or have a stress-inducing office job.
Stress in particular is in the upper tier of acne causes. Adrenaline and noradrenaline make acne bacteria more aggressive (see here), while the stress hormone cortisol disrupts your wound healing. The connection to acne? Vitamin C clears excessive cortisol from your bloodstream.
Consider the classic German study. 120 people prepared to give a speech, and all were very nervous. One group received 1000mg of vitamin C, and the other received a placebo. The first group’s speeches were as smooth as butter and the words flowed out of them like a pristine mountain stream. The second group jiber jabbered about nothing while shaking uncontrollably. OK, that’s slightly exaggerated, but vitamin C reduced cortisol, blood pressure and anxiety measurements during the speech.
Vitamin C is a key part of the stress response, increasing by 70% in the inferior vena cava vein during anxiety (study), and therefore getting seriously depleted. It’s known that during times of severe stress (like sliding off a mountainside), a goat will produce 100,000mg of vitamin C over 24 hours. It’s a survivor of evolution – the vitamin C stress response occurs in most animal species. Some scientists believe that losing the vitamin C production enzyme (l-gulono-lactone oxidase) has made us more vulnerable to psychological stress as a species. Guinea pigs and bats are other rare mammals that lack it.
There’s a reason why the adrenal glands are the second densest vitamin C location after the brain. Vitamin C is a vital co-factor in the adrenaline and noradrenaline they manufacture.
The raging battlegrounds in scienceville are definitely the common cold and cancer; there’s nothing on stress. Vitamin C can 1) decrease stress’ acne dangers in the moment, and 2) replenish the vitamin C stores that stress has depleted.
A normal situation is debatable. But if you’re highly stressed, I’m sure that breaking the 200mg boundary will benefit your acne.
The modern world
However, that’s another point: nowadays, there are far fewer “normal situations” than people think.
Firstly, we have smoking. The link is classic. Cigarette smoke is packed with 3 trillion invisible free radicals a puff. They travel into your lungs, and on average, deplete your vitamin C by 25-50% compared to non-smokers.
This study on 11,592 people found that the heavier the smoking, the lower the vitamin C. It occurred independently of dietary vitamin C, which is important because smokers also tend to shun fruit and vegetables. This study found that quitting smoking immediately restored half of the lost vitamin C in the bloodstream. Nobody is safe; second hand smoke can reduce vitamin C by 50% of what real smoking does.
While the WHO stubbornly refuses to change it, the US and Canada now recommend an extra 35mg daily for smokers. However, this study on 11,582 people concluded that only 200mg could make up the difference.
Luckily, smoking is beating a retreat in Western countries, but another threat to your vitamin C stores is rising and rising. Yes, it’s obesity. Vitamin C is often directly inverted to body fat percentage, BMI, and waist circumference (study). A higher body weight means more vitamin C stashed away in tissues rather than patrolling the bloodstream.
Adipose (fat) tissue is also highly bioactive. There’s mounting evidence that it generates inflammatory chemicals and hormones. One of them could easily deplete your vitamin C.
The real implication, however, is that other lifestyle factors might secretly deplete your vitamin C levels.
If you’re an expat studying in Beijing, then there’s the everpresent smog and its PAH pollutants. If eat lots of non-organic strawberries, then the pesticides could be chipping away at your stores. Sunlight won’t affect you much as vitamin C isn’t particularly important for UV protection. However, do you spray your armpits with deodorant every morning? The gas contains volatile organic compounds which deplete your antioxidants.
The point is that free radicals and chemical contaminants affect everyone. It’s highly unlikely that smoking is the only vitamin C burglar; it’s just been studied more because it’s a common habit.
Conclusion
Our verdict is divided into two clear halves. Firstly, the health body recommendations of 60-90mg are undoubtedly too low. You can forget about this number right now and focus on 200mg. I’m sure that newspaper articles will appear soon featuring scientists calling for higher RDAs.
Secondly, we have the murkier frontier of megadoses. Considering the smoking, the studies, and the lifestyle factors, I reckon that unless you’re chronically stressed, a decent starting point would be 500mg.
If you do take the megadose route, then space it out: one third each in the morning, afternoon and evening.
It’s been 273 years since James Lind coaxed a half dead sailor into swallowing lemon juice, but vitamin C’s actions in the body are still mysterious. Except in certain lifestyle circumstances, we simply don’t have enough data to judge whether 2 grams versus 500mg will achieve anything significant for acne.
One particularly mysterious acne element is collagen. You need vitamin C as a co-factor, to convert the amino acid lysine into hydroxylysine, which itself becomes allysine. Deficiencies cause premature wrinkling and a glowless nightmare, but where the cut off point lies is a mystery.
One thing is for sure: you can’t just take more and more and get firmer and firmer skin. An 80 year old couldn’t take 10 grams and look 50 again (imagine the spammy internet adverts if she could). The cut off point does exist.
Thanks for reading!