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. Vivian Thornhill Avatar
    Vivian Thornhill

    What about rose hips?
    I pick them in the fall and freeze some for the winter to make tea
    They are free to pick (grow everywhere here on the west coast of Washington) and very high in vitamin C

  2. Sarah Avatar

    Did you take the Essential C while nursing? I’m on board to move from lipsomal to a food based source but can’t find any info on if it’s ok while breastfeeding!

  3. Chelsea Kissiah Avatar
    Chelsea Kissiah

    I’m confused why anyone would choose synthetic vitamin c (lipsomal, ascorbic acid, etc) over a Whole Foods one such as Pure Synergy? Can someone tell me what I’m missing? What the benefits of the synthetic over the other???? I’m missing something

  4. Michele Avatar

    Here’s my dilemma, I’m hoping someone can give me ideas. I’m low in vitamin C however I can take liposomal because I cant have soy or sunflower due to allergy sensitivities. I can’t take any form of bioflavenoids because of overexposure sensitivities… I just don’t know where to turn. I’m afraid to try IV drips because if they contain bioflavenoids it will just make me sick. I only eat 1500 calories a day and consuming that much high C fruit, well that would only bring out the allergy sensitivities and way too much sugar. I’m so lost, can anyone help?

  5. Susan Avatar

    I don’t agree with the Mayo Clinic’s recommendations and warnings. What sources on nutrition do you trust?

  6. Shannon Avatar

    Didnt seem to help me at all in supplement synthetic form just seemed to make body more acidic even combined with magnesium and zinc, Id rather take probiotics that arent D-Lactate forming ones like L-Plantarum and L-Paracasei for better digestive health. Plantarum is important to fix leaky gut…

  7. Viola Avatar

    I’m wanting to make an after pool spray to neutralize chlorine. Would it be less beneficial if I premix the spray ahead of time, or should I wait to mix the sodium ascorbate with water until just before I want to spray?

  8. Alicia Avatar

    I would also love to know Katie’s opinion on sodium ascorbate. I keep hearing that it is actually a dangerous form of vitamin C ?


  9. Teresa Avatar

    Bioflavonoids, Quali-C, Rose Hips, time released, do any of these have a good benefit and what should I be looking for when purchasing a good Vitamin C supplement, that you for your input!

  10. India Avatar

    Great article explaining the benefits of Vitamin C. In addition, Vitamin C is essential for connective tissue repair. Although it is beneficial to athletes participating in a various sports, vitamin C is particularly important to body builders, since their training causes the most connective tissue damage. Vitamin C is also important to athletes because, it is as an antioxidant, and is believed to play a role in many different health conditions, including the aging process, cancer, and heart disease.


    Vitamin C has changed my life. At age one I had double pneumonia. As a child I was told by doctors who examined me and listened to my lungs that I should never smoke because my lungs were weak (this was in the 1950’s). I was plagued by “chest colds”. I would get a runny nose, it would drain down my throat, followed by a sore throat, them chest congestion. As an adult the result became bronchitis. I was put on heavy medication and would start my day with my wife pounding on my back to loosen up green gunk I would cough and spit out. Usually these occurrences ran a course of two weeks or so.I lamented to my doctor about this continual on going problem. His response was there was nothing I could do. Weak lungs did me in. Some people have weak stomachs, some get migraines, I had bad lungs By chance I read an article by Linus Pauling. He touted the value of vitamin C and he took 18000 milligrams per day. My wife, then a RN and her MS in nursing (now a PHD and nursing professor) said that was crazy. Your kidneys could never tolerate such doses. Nevertheless, I started at 2000 milligrams per day (age 29). Initially i could not absorb all of it (you pee a bright yellow orange is the tip off). Shortly I absorbed it all. Over the next year I increased, stopping at 6000 milligrams a day. I am 71 years old now and still take it EVERY DAY! I have had two sore throats and zero chest colds, obviously zero bronchitis illnesses since then! The last time I threw up with the flu was 1978, the only time I have thrown up since starting vitamin C! When I get the flu, and I do, i run a little temp for maybe 12 hours, ache, and feel run down. I just work through it and it is gone. I work still about 70 hours a week. I NEVER miss work. We raised three kids and now babysit grand kids. I work with the public and am exposed to all routine colds and flu and am effectively immune. Vitamin C is the elixir of life. I have not had one antibiotic since I started on it. You can discount this as some make up story but there is not even any exaggeration in it. To sum, in my case, there have been no side effects, to my knowledge, by taking higher doses. Occasionally even now, I will pee bright yellow orange, so for whatever reason, that day my body did not absorb it all. I am a high energy guy who goes all the time and sleeps little. I have no idea if vitamin C has anything to do with that, I have always considered myself high energy, but I can testify that I eliminated my lung issues and it was a direct correlation to my starting taking it. I have nothing to sell. I share this so that you seriously realize, at least in my case, and I am no one special, vitamin C drastically changed my life and I am talking for over 40 years.

  12. Sam Avatar

    What do you think about Garden of Life Vitamin C? Each capsule has 250mg of natural, raw vitamin C.

  13. Jill Avatar

    I have toxic mold illness, and I’ve been told ascorbic acid–in fact, most Vitamin C, is made from a mold source, which of course I can’t have. I looked into a whole food Vitamin C, but it had brewer’s yeast as an ingredient (which moldies can’t have either). Is there any way to know what the source for liposomal Vitamin C is?

  14. Geoffrey moni Avatar
    Geoffrey moni

    Ascorbic Acid or Vitamin C as it is known to the majority of us who take it is a very strong immunity booster. I am diabetic and therefore I benefit by taking it once in a while. The Sources of this vitamin is mainly from fruits which have a lot of medicinal value making it important to those who run short of taking enough fruits as often as necessary by filling that vacuum.

  15. qiaraau Avatar

    Taking vitamins will help you to become healthy, but taking vitamins and probiotics is healthier. Probiotics and vitamins work together really well in the body. Probiotics can help vitamins to be separated and used in the body through the digestive processes. Vitamins do not impede the probiotics role, just as probiotics do not hamper the vitamins potency.

  16. Grace Avatar

    What vitamin C product might you recommend for giving to a child on a daily basis?

  17. Rich Coulter Avatar
    Rich Coulter

    J. Ireland if you have a “sensitivity” to it, it’s not pure ascorbic acid. C6H8O6 is C6H8O6 whether it’s grown in China, Uganda or Mars. It’s scientifically impossible to look at C6H8O6 molecules and know how they were formed, in what country and from what food types.

    That said, one need only shop for “Quali-C” if they want to avoid GMO corn and China-made ascorbic acid. Wanting to avoid consuming GMOs isn’t a valid reason as again, C6H8O6 = C6H8O6, there is no DNA component. However wanting to avoid supporting the GMO industry and the companies that profit from GMOs as well as not supporting that type of agriculture thus being a steward to the planet, all valid reasons.

    Quali-C is 100% made in Scotland where use of GMO ingredients is either prohibited or would require clear labelling. The Vitamin C Foundation uses Quali-C in their products and you can find a few Quali-C options on Amazon as well such as Dr’s Best.

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