Ascorbic Acid: Vitamin C Benefits, Sources & Cautions

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Wellness Mama » Blog » Health » Ascorbic Acid: Vitamin C Benefits, Sources & Cautions

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?

Vitamin C- sources benefits and cautions

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?

Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


158 responses to “Ascorbic Acid: Vitamin C Benefits, Sources & Cautions”

  1. Martina Robert Avatar
    Martina Robert

    Hi..Some people recommend taking vitamin C supplements twice a it safe to take like this..

  2. Emek Blair Avatar
    Emek Blair

    We also just published a paper, “Liposomal-encapsulated Ascorbic Acid: Influence on Vitamin C Bioavailability and Capacity to Protect Against Ischemia–Reperfusion Injury.”

    There is plenty of evidence the vitamin c has significant positive health effects.

  3. Tasha Avatar

    Juice fresh organic oranges a day and you will receive the vitamin C you need. Don’t take the synthetic. I’ve seen all the posts and watched quietly, but trust me the vitamin C you really need is in your juices, herbs and veggies. Juicing parsley has an extremely high amount of vitamin c, as well.

  4. Hena Avatar

    Is it safe to take Pure Radiance C while breastfeeding or even while pregnant? I have not found safe information about all the ingredients. Thanks.

  5. Kate Avatar

    For anyone who’s interested: I’ve asked both a midwife and a doctor about taking vitamin C during pregnancy and they both cleared it. “Pure Radiance” is what I take, it comes in capsule and powder form. However, keep in mind that since it comes from a plant source you don’t need to take as much as if you were taking the synthetic stuff. During pregnancy, you can take anywhere from 500 to 2,000 mg depending on your practitioner’s recommendation.

  6. Nataliya Abayeva Avatar
    Nataliya Abayeva

    “A second study presented to the American Heart Association showed a link between consumption of only 500mg of vitamin C per day and a greater propensity toward thickening of the arteries”

    Please see:

    “Vitamin C / Atherosclerosis scare”

    Excerpt: “1) The study demonstrates no evidence of occlusion (or clogging) contrary to media reports. The USC team used a new, sensitive method of carotid ultrasound that measures three factors: 1. arterial thickening; 2. degree of plaque or atherosclerosis; and 3. blood flow. While there was evidence of thickening, there was no evidence of plaque or diminished blood flow velocity.

    2) The clinical implications of “thickening” of the arterial wall are unclear. The sensitive technique of carotid ultrasound used in this study is brand-new, and researchers haven’t yet concluded that the tiny changes measured are indicative of eventual stroke risk. An equally plausible explanation of the thickening seen can be inferred from vitamin C’s known role as a collagen repair nutrient. Elderly patients with fragile, thinned blood vessel walls might well benefit from the effect.

    3) Last year, the same USC research team (Dwyer, et al) wrote a paper with opposite findings, casting doubt on the new study’s conclusions. Additionally, the new vitamin C paper doesn’t make sense and flies in the face of much of what we already know about vitamin C’s protective role against cardiovascular disease. Recently, studies have shown that vitamin C, when infused directly into the arteries, promotes relaxation of the blood vessel walls facilitating blood flow. We know that vitamin C is an important member of the antioxidant team, counteracting free radicals that are acknowledged to be culprits in promoting blood vessel disease, especially in at-risk populations such as smokers. A recent paper by Simon in Epidemiology (August 1998) showed that for each 0.5 mg. per deciliter increase in blood levels of ascorbic acid (C) there was an 11 percent reduction in coronary heart disease and stroke reduction in a group of more than 6,000 U.S. men and women. Compared to individuals with low or marginal levels of C, there was a 27 percent reduction in heart disease and a 26 percent reduction in stroke in the group with the highest blood levels of vitamin C. No wonder the Nobel Laureate Dr. Linus Pauling made vitamin C the cornerstone of his cardiovascular disease prevention program, personally taking up to 20 grams a day until his death at age of 92. The additional details are emerging on the vitamin C story, but I’m sure that the ultimate conclusions will only fortify our confidence in nutritional supplementation as the basis for a rational heart disease and stroke prevention strategy.”


    “Linus Pauling Institute’s response to the recent article on vitamin C and atherosclerosis”

  7. Jacqueline Bahle Avatar
    Jacqueline Bahle

    Hi, My name is Jacqueline. I started to take vitimin C and vitimin A to help out my arthritis, when I was 30 years old. It helped me a lot. As I got older different doctors (as my husband worked in a lot of states) would give me medicines to things they said I had. When I hit 45 years, I did not take anymore of anything they would give me, as it never seemed to help me. Bottom line, I remember reading a book by Brian Wilson, of the “Beach Boys”, and in it he says he was taking 20,000 vit. C a day, I had also read about Dr. Pauling, so I started to take more C, every 4 hours to bowel tolerance. vit. C does not stay in your body very long, Jump to now, I will be 87 years old in January, 2017, and will swear by vit. C. I also do take other vitamins with the C, but the C is by far the best. I can’t remember when I had a cold or flu. People tell me I don’t look my age, they say I don’t sound my age (on the phone). Also I don’t act my age, but to my dismay, I do walk my age. As you may have noticed, I am not good on paragraphs etc. , so I will chalk that up to old age. I hope this helps someone, as I always like to help people. I have 5 children, 13 grandchildren, and also 13 great grandchildren. I have a lot of them on vitamins. Take care Jacqueline

  8. Jen Avatar

    What about Vitamin C derived from Tapioca? It’s absorbic acid but is not synthetic. Am I missing something (probably!)?

  9. Jo Avatar

    Im wondering how much Camu Camu you took when you were taking it?
    Adult dose and child dose please.
    Thank you.

    1. Jammin Avatar

      Interesting article…it is completely opposite of what is written here about the Vitamin C. It makes it all confusing and challenging, if not disappointing to know which is the right Vitamin C source to use.

      1. Rich Coulter Avatar
        Rich Coulter

        What is written here is wholly incorrect, ascorbic acid is NOT synthetic as it is the molecule nearly all mammals make within their own bodies. How can it not be natural? This is not folate vs. folic acid, this is not the Vitamin E complex of 8 natural forms vs. the rubbish dl-alpha tocopherol used to try and convince men that E increases prostate cancer risk, this is ascorbic acid. It’s like saying H20 is synthetic water.

        Here is a great resource –

  10. Lisa Avatar

    I just checked out your claim about vitamin c causing cancer. The only places I can find with a claim anything like this are coming from sources like the FDA and the American Medical association. Not exactly trusted sources of info on nutritional research. Numerous scientists and organizations have cretiqued these studies and pointed out the gross methodological flaws in them.

    I found a science daily article about how chromium 6 the toxic substance the the Erin Brochovich case is made more toxic by vitamin c, but the vitamin c in foods produces this effect. So the problem is the chromium 6 and the answer is to get rid of it not get rid of vitamin c.

    I think you need to do much more and much deeper research.

  11. Lisa Avatar

    I would be highly skeptical if I were you about the claim made about dr szent gyorgi. I can’t find anything to corroborate this. There are a lot of people in the “natural vitamins” camp making up or parroting made up stuff like this. I’ll give you another example. Dally Fallon in Nourishing Traditions or the Weston a price website says that synthetic b vitamins failed to cure people with pellagra or beriberi and the unpolished rice was successful where b vitamin supplements were not. I was skeptical so I researched it. Every bit of info on these outbreaks and the treatment for them said the exact opposite that recovery was much better and faster with synthetic b supplements compared with food only.

    There are a lot of reasons why people have motives to twist the truth. It can be because they sell overpriced “natural” vitamins or because they have just fallen in love with this idea and want to promote it and believe it. It pays to always be very skeptical and not easily believe whatever you are told. Search out the opposing arguments before swallowing ideas.

  12. Lisa Avatar

    Vitamin c is not a complex. The substances claimed as part of a vitamin c complex are not made by the livers of animals that produce their own vitamin c which is ascorbic acid. There are many substances in plants that have beneficial effects of various sorts which is why we should eat plenty of whole foods. But the claim that vitamin c is a complex that includes such substances as flavinoids is unscientific and false as is the claim that the intake of generous amounts of ascorbic acid is harmful. If this was the case then most animals who make large amounts of ascorbic acid endogenously would be harming themselves.

  13. Esteri Avatar

    Do you think dried fruit powders have the amount of vitamin c they say they have after being processed. Anybody know how they test camu camu after it is processed and packaged and how it retains it vit c after being opened and used. I suppose the ideal thing would be to freeze it as soon as opening it? What would be the next most concentrated Vit C powders?

  14. Kayla Avatar

    Do you take this Pure Radiance Vitamin C while pregnant? Is everything in it safe?

  15. Candace Avatar

    I also take vitamin C, especially in the winter months. I also like for my kids to take it. My mom owned a health food store when I was growing up, and she was a big believer in vitamin C to prevent illness and help us get better faster. It has stuck with me my whole life. Sometimes, I will blend up a mixture of immune building real foods – garlic, cayenne, ginger, lemon juice, raw honey, etc. and take it when I feel like I’m getting sick. I’ve heard that there is actually more vitamin C in the pith of the lemon than in the juice. One question – what are your dose recommendations when taking vitamin C as a supplement? My mom always said that since vitamin C is water soluble, the body will just use what it needs and eliminate any excess – so not to worry about getting too much.

  16. Shay Andrews Avatar
    Shay Andrews

    Hi Katie,
    Im wondering how much Camu Camu you took when you were taking it? MRH cant tell you how much vitamin C is in their Camu Camu powder, so I’m not sure how much to take daily?

  17. Maria Avatar

    I used to really enjoy reading your blog. But this biased article spread with myths and affiliate links to Radiant website which sells uber-expensive ‘wholefood natural’ vitamin C made me pause. There is an overwhelming research regarding the benefits of ascorbic acid and sodium ascorbate which has been used therapeutically from the 1940s.

    Look into the works of Linus Pauling – two times Nobel price winner, Albert Szent Gyorgyi, dr. Cathcart, dr Klenner, Irwin Stone and so many others who used pure ascorbic acid – which is what animals make in their livers as well, and which is what humans made as well until that particular gene became defect in us. There is not even one study which proves that the marketing-gimmick natural wholefood bla bla bla vitamin is any better than the straight up one, which is used in high quantities for almost everything that is an illness affecting people. But then again 1 kg of ascorbic acid costs the same as 100 gram of your affiliated product Radiant. How do you think people can supplement a ‘la orthomolecular therapy with Radiant product you are endorsing for $? No wonder – from ascorbic acid you’d get no commission, afterall it’s dirt cheap.

    With this I say this blog good-bye. You’ll probably not even allow this comment, but at least you’ll see it.

    Maria – who is taking 20-25 grams of ascorbic acid per day and is feeling better and better every day.

    1. Wellness Mama Avatar

      Hi Maria… I’m sorry to hear you feel this way, and while of course you might not see this since you plan to no longer read my blog, I felt the need to respond to certain claims that you made because they are incorrect and in some cases directly insulting. Yes, there is a lot of research on Vitamin C (often in Ascorbic acid form) since the work of Dr Pauling (and others). There are recent studies that show that ascorbic acid may cause certain genotypes that lead to cancer, may interfere with antioxidant production, can affect gut bacteria in a negative way, and potentially be linked to heart problems. Of course, if a person had a serious illness, concerns like those would be outweighed by the potential benefit of vitamin c, but it certainly brings questions of using synthetic vitamin c every day or for minor illnesses.
      As far as affiliate links…. I have never tried to hide in any way that I use affiliate links on this website (my affiliate disclosure is linked to at the top of every blog post: ), and I could have just as easily linked to ascorbic acid. That said, I recommend the products I think are best. Sometimes (and often) these products cost more as you typically get what you pay for, but I’ve also happily linked to products where I had no affiliate link if that was the product I felt was best. In other words, if I’m linking to a product I have an affiliate link for, I include it (this helps cover the cost of the rather expensive hosting it takes to keep Wellness Mama running each month), but if I don’t have an affiliate link, this does not affect my decision to link to it.
      Additionally, while ascorbic acid is what many animals naturally make, we do not, and it is highly unlikely that any person would be able to consume 20-25 grams of vitamin c from natural food sources, especially in an isolated form, so at that point it is more like a supplement or pharmaceutical and should be used with care (especially at this dose). I’m so glad you are having good results, but for the sake of anyone else reading this, I’d absolutely have to recommend finding a qualified naturopath or doctor to help with any treatment that involved that high of a level of any isolated nutrient.

      1. Steven Burke Avatar
        Steven Burke

        No it’s not “often” in ascorbic acid form (which is vitamin C) it’s ALWAYS in ascorbic acid form. Every other form written about is buffered, which is still ascorbid acid.

        The problem here is your article is steering people away from vitamin C, because ascorbic acid is vitamin C, and steering them towards products that have absolutely ZERO scientific evidence supporting them and include things with names you can’t identify what there are, what a shame.

  18. Yoli Avatar

    Hello Katie,

    I have seen a few questions about Vitamin C for babies and kids, but did not see a response. Can you help me? I have an 11 months old boy and a 4.5 year old girl and I would like to give them Vitamin C Supplements.
    I love your posts and I always come to your website when I have questions about various issues.

    Thank you,

      1. Kelly Avatar

        Hi, I’m just curious why you give a different vitamin c to your kids…is the Pure Radiance not safe for children? I too have been looking for one for myself and for my children.

        1. Wellness Mama Avatar

          It is, but it is a little more bitter and they like the liposomal one better but I have given them both. With the pure radiance, I found that mixing it with a little honey or juice helped the taste for them

  19. Franciane Avatar

    I’d like to know if this vitamin C is safe for pregnant women please? 🙂
    Thank you!!!

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