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Vitamin C has a rich and surprisingly controversial history. On the one hand, science is clear that the body needs it, but the type, dose, and frequency are all up for debate.
When the common cold is making the rounds, many people turn to vitamin C, also known as ascorbic acid, to help ward off illness. Without it, immune system function declines. Studies also show that without adequate vitamin C the lining of blood vessels and membranes of cells deteriorate. It is a big deal!
But, before downing a lot of prepackaged packets of vitamin C (probably with artificial colors and sweeteners), it is important to understand which forms of are most effective and how to safely consume it.
What is Vitamin C?
Vitamin C is a water-soluble vitamin that is needed for many reactions within the body. Humans are not capable of making it internally (most other animals can manufacture it in their livers). Vitamin C is present in many foods, especially brightly colored vegetables like bell peppers and citrus fruits, among others.
Since the human body does not manufacture or store vitamin C, it must be obtained regularly from diet (or supplements). Though low level vitamin C deficiency is common, severe deficiency (also known as scurvy) is rare in modern times.
Vitamin C is a powerful antioxidant, meaning it can help protect the body from the damage of free radicals. On a practical level, this means that it protects cellular health, reduces the effects of aging, and boosts the immune system.
I first learned about the benefits of vitamin C in high school when I had to do a research paper on Dr. Linus Pauling, a Nobel Prize-winning chemist who is considered one of the fathers of biochemistry. He spent much of his career studying vitamin C and even wrote several books on the vitamin’s impact on health. His work provided much of the current understanding of this important vitamin.
How Much Vitamin C Do We Need?

Now, things are going to get hairy. The answer is that it depends on who you ask and when.
Modern research is divided and every health expert seems to have a different opinion. Like many aspects of health, the answer is likely that it depends and that it is different for every individual.
For many healthy people, it is likely possible to get enough vitamin C from rich food sources like certain fruits and vegetables. Certain supplements also contain just whole-food sources of vitamin C and can be beneficial for those wanting to slightly increase their vitamin C consumption.
Research shows that those with certain conditions may benefit from supplemental vitamin C as well, sometimes even in the form of an IV. In fact, some doctors are experimenting with high-dose IV dosing to help in recovery from serious illnesses, surgery, and even cancer.
Linus Pauling himself was rumored to take 12,000 mg or more of vitamin C a day (and he lived to 93)! Since up to a third of people are deficient in vitamin C, it can be important to supplement, but the type absolutely matters!
See what I personally do at the bottom of this post, but do your own research and talk to your own doctor to see what is best for you.
Benefits of Vitamin C
Today, even more science backs up the benefits of optimal amounts of vitamin C. Here are the main health benefits of vitamin C according to current medical research:
1. Boosts the Immune System
Perhaps the most well known benefit, and with good reason. Administering extra vitamin C is always part of my cold and flu protocol. Interestingly, this is also one of the more hotly debated benefits. Several reviews of all randomized controlled data showed little or no effect on colds from vitamin C supplementation. Most of these studies looked at small doses or at the effect after the onset of colds.
Other studies showed benefit from larger doses and from taking vitamin C before the onset of illness. Most notably, one study showed a reduction in symptoms and duration of a cold from one 8 gram dose of ascorbic acid on the first day of symptoms. (Fair warning, a dose that big will likely reach “bowel tolerance” and mean diarrhea for a few hours).
What I do: I start each day with the juice of one lemon in water, which yields about 30 mg vitamin C. I take a food-based vitamin C supplement daily. I also take bigger doses of ascorbic acid during times of stress or illness … more on that below.
2. Supports the Brain
A lesser known but equally important benefit of vitamin C (and why it is part of my daily routine).
The brain maintains vitamin C levels even with other parts of the body show signs of deficiency. In fact, the brain often has 100x concentration as the rest of the body and likely for good reason!
Vitamin C helps the brain in several important ways:
- reduces reactive oxygen species and protects against neural damage
- promotes the healthy development of neurons and supports the formation of myelin
- supports optimal neurotransmitter production
- leads to expression of BDNF (brain-derived-neurotropic-factor)
- may even help avoid Alzheimer’s Disease according to recent studies
3. Fights Oxidative Damage in the Body
As you are probably already aware, free radicals and oxidative damage are bad news.
Vitamin C is a potent antioxidant that correlates with reduced risk of disease and longer lifespan, likely because of its ability to reduce oxidative damage and free radicals.
Specifically, studies have found that vitamin C is especially effective at reducing damage in the lungs. This is why RDA guidelines recommend higher vitamin C intake for smokers. Ascorbic acid is also sometimes used in conjunction with cancer treatments to help mitigate oxidative damage.
For those of us who (hopefully) don’t smoke or have cancer, a diet rich in vitamin C and some occasional supplements will likely just help keep inflammation at bay.
4. Boosts Mood and Libido
I notice I am generally happier and feel better when I get enough vitamin C. (And vitamin D, but that is a topic for another day). But science supports my anecdotal finding…
Studies link severe deficiency of vitamin C to emotional instability and anxiety. In one study adequate consumption led to a 35% reduction in mood disturbances and increased oxytocin. Yet another study found an increase in libido from 3,000 mg a day supplementation.
Yet another reason to start the day with lemon water!
5. Promotes a Healthy Heart
The jury is still out on this one, but some studies show that diets high in vitamin C seem to reduce the chance of heart disease and stroke. This is logical, since vitamin C is naturally found in fruits and vegetables and consuming enough of these is also great for the heart.
Another study showed that vitamin C may increase HDL cholesterol and reduce small particle LDL. The latest research even shows that this vitamin may reduce arterial plaque and strengthen blood vessels.
6. Boosts Collagen Production and Improve Skin
Internal and topical vitamin C can help increase collagen production and improve skin health.
Vitamin C helps stabilize collagen and improves the connective tissue in the entire body, including the skin and bones. It is widely used in beauty products since it induces collagen synthesis. Studies even show that it may slow the natural aging process by protecting and improving the body’s collagen.
Topical treatments are clinically shown to reduce the appearance of wrinkles, lines, and sun spots. I often mix a little ascorbic acid powder into my face wash to get these benefits. I also make this facial serum for additional skin benefits.
7. Supports the Adrenals
I also increase my intake of “C” when I’m stressed because it is directly used by the adrenals.
Though this tidbit is less well known, vitamin C is necessary for healthy levels of cortisol. It is found in high concentrations in the adrenal glands and can become rapidly depleted during times of stress.
Types of Vitamin C
Vitamin C is naturally found in many foods, and when possible, this is the best and safest way to consume it. As I’ve said before, you can’t out supplement a bad diet, so even if supplements are needed, diet must come first.
A note on vitamin C and when to consume/take it: vitamin C also helps the absorption of iron, so I try to take it with meals where I eat a real food source of iron.
Food Sources
To get vitamin C from food, consume plenty of raw vegetables and fruits like brightly colored bell peppers, citrus fruits, acerola cherry, broccoli, cauliflower, and others. This is just good advice in general but also great for ensuring healthy levels of vitamin C.
As I mentioned, my regular go-to is drinking lemon water each morning.
Food-Based Supplements
Even with the best of diets, getting adequate vitamin C from food can sometimes be difficult or not possible. In fact, it’s one of only five supplements that Chris Kresser recommends supplementing with since it can be so hard to obtain from food.
Unfortunately, heating destroys much of the vitamin content in food, so unless a person is consuming a wide variety of raw brightly colored fruits and vegetables daily (which is difficult in the winter months), supplementation can sometimes be helpful. Studies have also shown that the nutrients in food have declined over the last 50 years, and this includes vitamin C.
What I Take Daily:
I take a food-based C supplement daily because it is a relatively small dose and makes up for nutrients that aren’t present in food anymore. My favorite is this Essential C Complex.
Ascorbic Acid
The least expensive and most-studied type of vitamin C is ascorbic acid powder. I keep a big bag of non-GMO ascorbic acid around for use at the first sign of illness but don’t take it daily. I also mix ascorbic acid into one-time use skin applications like face masks and into my daily cleanser. It loses its effectiveness quickly when mixed with liquid so it doesn’t work as well for topical uses when pre-mixed into big batches.
Liposomal C
This form uses a specialized technology that is said to make it more bioavailable and much less acidic. My kids love the taste of this one and take it willingly so I always keep it around. It also has great reviews for skin health and I’ve been experimenting with making it part of my daily routine along with a liposomal turmeric.
Cautions and Risks
This essential vitamin is water soluble and generally considered safe at doses up to 2,000 mg a day, according to the Mayo Clinic. At doses larger than that, it can potentially be problematic. Diarrhea is the most common side effect. At extremely large doses, vitamin C may also carry the risk of increasing the likelihood of kidney disease. Pregnant women should also not take doses above the recommended daily amount as it may cause problems for baby.
This article was medically reviewed by Dr. Scott Soerries, MD, Family Physician and Medical Director of SteadyMD. As always, this is not personal medical advice and we recommend that you talk with your doctor.
What do you think about vitamin C? Do you take it or try to obtain it from food?
Thank you for posting this informative article! I have already known of the importance of natural vitamin c but my husband and I have felt isolated on the subject amongst friends and family so it feels good to know that we are not alone. We use the natural vitamin c from Healthforce, and we also drink vitamineral green and earth. I think it is more effective than traditional medicine in the event of illness too. When my daughter was 2 months old I developed mastitis and drank nothing but water and vitamin c. My fever broke in less than 24 hours and I felt almost completely better within 48 hours. I have a couple of friends who used traditional medicine for the same thing and did not feel better for a good 5 days. Natural vitamin c is truly wonderful for the body.
What are the 5 supplements recommended that you mentioned were hard to get from foods?
I think the five he recommends are: A, D, K2, Magnesium and Vitamin C
Whoops !! In this article you neglected to mention the benefits of sodium ascorbate., another form of vitamin C. Research indicates it is preferred over ascorbic acid.
Be Well ….
Does the Pure Radiance Powder have a taste at all?
Also, just read about treating whooping cough with high doses of Vitamin C, but Dr. Suzanne Humphries recommends only using sodium ascorbate. Would the Pure Radiance Powder compare…?
It does have a taste, mildly bitter but I actually really like the taste. I’ve found that I need less of this than ascorbic acid or sodium ascorbate.
Katie, is this form of vitamin c tolerated by people with reflux? We usually have to avoid the acidic citrus fruits which makes getting our C more difficult.
So, steamed broccoli, cauliflower, kale, ect are not good sources of Vitamin C?
Not so much… Again, the heat breaks it down.
Thanks, I have always used vitamin c and think it really helps. I was thinking that the cheaper powders were not a good source and now you confirmed that. I am with you whatever we can get from food sources are the best! I love your blog and so glad you have touched so many lives! I am a blogger as well and love helping people with their health! Keep up the great work Katie!
I use Nature’s Way Alive Vitamin C. It’s made from only 5 ingredients: organic acerola, organic goji, organic kiwi, organic amla and manioc. Great in smoothies!
As someone who take high dose vitamin c daily as well as making my own liposomal c, I have done a ton of vitamin c research I have a bit of a different take on vitamin c:
Unlike certain vitamins (vitamin e for example), vitamin c from natural and synthetic sources is molecularly identical, meaning there is absolutely no difference at all whatsoever between vitamin c from a natural or synthetic source. They have no difference in activity in the body, in absorption, in bioavailability, or in any other aspect, they are exactly identical molecules.
“Natural and synthetic L-ascorbic acid are chemically identical, and there are no known differences in their biological activity. The possibility that the bioavailability of L-ascorbic acid from natural sources might differ from that of synthetic ascorbic acid was investigated in at least two human studies, and no clinically significant differences were observed.” [http://goo.gl/dbCFG0] (link for source citation)
Also, vitamin c is one of the vitamins that has no co-factors that affect its bioavailability in the human body, no mammal that makes its own vitamin c makes the other molecules you mention, nor are those used by the body to assist with the usage of vitamin c in any way.
“Results from the 10 clinical studies comparing the absorption of vitamin C alone or vitamin C in flavonoid-containing foods showed no appreciable differences in bioavailability of ascorbic acid.” [http://goo.gl/dbCFG0] (link for source citation)
When you buy pure vitamin c it is only the vitamin c molecule, there are no genes or other chemicals or allergens present at all, only pure C. Vitamin c is crucial for humans because we are one of the few mammals that contain a damaged copy of the gene required to make vitamin c internally meaning we have to consume it. Mammals our size require a LOT of c. Vitamin C is one of the safest, most helpful supplements you can take, and ascorbic acid is ascorbic acid regardless of the source, just look for a pure form.
As a long time reader and commenter on your blog, I appreciate the posts and resources you’ve provided. Thank you.
I totally agree. I have been making home made liposomal for two over years now and we have found it to be the single most effective treatment for colds and wound infections. I have a friend who uses liposomal and has gut dysbiosis. Taking straight ascorbic acid gives her symptoms of gut damage, but liposomal doesnt – which shows that it is truly going straight into the bloodstream bypassing the gut all together. When you take a dose of liposomal, you feel the benefit immediately!
Hi. So how do you make liposomal Vit C?
make sure your ingredients are all non-gmo
Non-GMO means nothing on it’s own. All powdered lecithins are produced with chemical solvents, acetone/hexane. So Non-GMO it’s pointless. Further there is no current sunflower lecithin on the market which is Non-GMO. The one company that produced it in Italy was put out of business. Liquid Lecithins are the only Non-GMO, non-chemically processed lecithins available.
What ultrasound machine do you use for making liposomic?
Can you tell us how to make liposomal c. Also how much should one take if they have extreme adrenal fatigue.
I’ve been dealing with adrenal fatigued for two years. While I had been kind of fatigued for like ten years, sleeping 10 to 12 hrs a day, I would have a pretty normal life and feel energetic my awakened hours; but suddenly my adrenals shut down and I was in bed extremely fatigued sleeping 20hrs a day. Doctors wouldn’t know what was wrong with me for like a year and a half, so I started detoxifying and filling nutritional deficiencies with mega vitamin supplementation following doctoryourself.com advice. Doing that got me out of bed and completely healed my suicidal depression (I had that too). It did not healed my adrenal insufficiency but it helped a lot. Finally and ND found out about my adrenals and now am doing hormonal replacement therapy (since my case is so severe). Natural hormones are always better if you have to do them, but it’s safer to try and rebuild the endocrine system with herbs and glandular extracts. The book Adrenal Fatigue by Dr Wilson explains it. And as a curious note: the highest amount of vit C in the body is in the adrenal glands (Dr Jefferies Safe Uses of Cortisol). I hope this help 🙂
Do you use Pure Synergy Pure Radiance C or Paleovalley ESSENTIAL C COMPLEX now and why.I think you used to use Pure Radiance ,but now you recomend Paleovalley?
All of them are excellent products and I use all of them from time to time…
Thank you .I used to mix some raw camu camu powder in my and my kids smoothies ,but wanted to add more nutritions.And still wondering is it better to get camu camu,acerola and amla separately or buy some of these two brands.
Absorbic acid is not vitamin C. Absorbic acid is only the outer sheath. It does have co-factors, namely P, J, & K, plus others. bioavailability may be identical, but how it works after getting into the body is different.
Here is some contrary information from the Linus Pauling institute: https://lpi.oregonstate.edu/mic/vitamins/vitamin-C/supplemental-forms
Note that all studies done on Vitamin C have been done using ascorbic acid.
See Thomas Levy, M.D.’s answer to this question @1:40:00 here https://youtu.be/CUUZTNjV9dI?t=1h40m20s (he is the author of “Curing the Incurable: Vitamin C, Infectious Diseases, and Toxins, 3rd Edition”)
While it is certainly preferable to obtain nutrients from food, it is almost impossible to consume the amounts of vitamin C from food to achieve levels proportionate to those in other mammals (worse, I recall reading that recent tests of commercial oranges showed very low or almost nonexistent levels of vitamin C — organic were not much better — probably due to selective breeding to increase sweetness). Pauling and others have demonstrated a number of disease prevention/cures from high doses of ascorbic acid. The key is frequent consumption at lower levels — e.g., it’s better to take 500 mg. 4X/day than 2000 mg. 1X/day — as the absorption/excretion rate of C is fairly short (an hour or two). Others have recommended buffering ascorbic acid by add 1/2 as much (non-aluminum containing) baking soda (sodium bicarbonate) — it is sold as such (or with other mineral buffers) but it’s much cheaper to DIY.
I usually take the buffered ascorbic acid with some lemon or lime juice as there are other factors in the fruit that may be beneficial either alone or in combination with the vitamin C. It is true that almost all ascorbic acid is manufactured from corn. While I avoid (esp. transgenic) GMOs, it is my understanding that these foreign genes/chemicals are in proteins, of which there shouldn’t be any in synthesized ascorbic acid. Whether it’s corn or any food source, extraction and purification involves chemical processes that are not “natural” — there’s a lot of hype about “natural sources” — it’s not possible to extract and concentrate vitamins from food by any other means.
Brandon, thank you for your amazing links. So much marketing and fear out there. Science uses ascorbic acid. If you got the money, i guess spend it on these WholeC products, but I’m not gonna be afraid of using ascorbic acid
Im a big fan of Katies articles and recipes, even though I sometimes disagree in certain things lol. Vitamin C is the safest supplement one can take, and we should take. Thanks for the links Brandon. I have been taking 9 grams a day of vitamin C in divided doses for eight months now, planning on doing it for life. If I ever come down with some sort of illness or dealing with extra stress, I also use the liposomal form from Liv On Laboratories. http://www.doctoryourself.com excellent website with a huge compilation of scientific papers related to vitamin C; including, of course, the two unshared Nobel prices winning Linus Pauling’s. I healed my depression thanks to doctor yourself.com, and I was very suicidal. I am still struggling with some symptoms of chronic fatigue, but I am a lot better and recovering :))
I have the Doctor Yourself Book. Love it! Drastically improved our lives with Vitamin C megadoses.
What would be a good supplement for kids?
I love Metagenics brand. Their Ultra Potent C Chewable vitamins are perfect for kids and they work great. 250 mg per tablet and I cut them in half for my 3 yr old. Also, checking Labdoor for quality control is important even if someone recommends a brand as superior.
Just ordered pure radiance! Do you have a recipe for gummies for my kids to take it in that form? I have gelatin and can get juice but just don’t know proportions and dosage amounts. Thank you!
It would depend on how many gummies you’d want them to take a day and how big they were. I typically just added the vitamin C (or other vitamins) and wrote down how much I added so once I cut them up or popped them out of the molds and knew how many there were, I could figure out how much each individual gummy had.
Ok, so here’s my statement and question…. Whooping Cough and Vitamin C: Dr. Suzanne Humphries recommends a protocol that requires high doses of vitamin C that I have read from several people has proven effective in shortening the duration. But, as you have mentioned in this blog, synthetic vitamin C kills good and bad gut bacteria, which is not what you want when you have whooping cough. I have searched far and wide for a natural supplement that could replace these high doses, but none exists. There is the supplement you recommend by Pure Radiance and also one made by Activz, but both of these are pretty low on the mg chart. So, I know you are not a doctor, but I’m asking your opinion or any information you can provide dealing with this topic. Has your family dealt with whooping cough and what protocol did you use? Or, do you think using either of these Vitamin C’s in high doses would be a better idea? I am primarily concerned with Vitamin C options. Or, do you just bite the bullet and go with the synthetic for such an issue as whooping cough? Thank you.
I would say the sodium ascorbate would be a good choice for anyone dealing with whooping cough. Even if it does kill both the good and the bad bacteria I think it’s better than the antibiotics your doctor would prescribe you. Just have to make sure you’re taking/giving a really good probiotic between taking the vitamin C.
Just read on Labdoor vitamin C testing that Pure Radiance C was rated poorly- can read it yourself. Am disappointed was recommended on this site. What is up with that?
For a better understanding of Ascorbic Acid, I recommend this article:
https://www.peakenergy.com/articles/nh20160215/The-most-popular-vitamin-C-myths-exposed