By Cat, June 2007; updated May 2019
Vitamin C is considered essential for humans because we lack the enzyme necessary to produce ascorbic acid in the liver from glucose. For this reason, it is vital that we include it in our daily diet. It is necessary for:
- Synthesis of collagen (14);
- Synthesis of the neurotransmitter norepinephrine (crucial for brain function) (14);
- Synthesis of carnitine (14);
- Metabolism of cholesterol to bile acids (14);
- Protection of DNA and RNA from free radical damage (14);
- Promoting wound healing (14);
- Aiding immune function (14);
- Protecting against cancer (14);
- It is a constitutional component of tendons, ligaments, bone, and blood vessels (14); and
- Detoxifying and regenerating hormones (15:).
Vitamin C hit many headlines upon publication of Linus Pauling’s book, “Vitamin C and the Common Cold,” but it is also well-known for prevention and treatment of scurvy, and is becoming better know for its help in treatment of certain cancers.
- Includes: 1. Food Sources, Dosage, and Toxicity of Vitamin C; 2. Benefits & Risks of High-Dose (intravenous) Vitamin C;
- See also: 1. Diet & Health Menu; 2. Vitamins: Intro; 3. Supplements vs Whole Foods (Intro); 4. Vitamin A; 5. Vitamin B complex; 6. Vitamin D; 7. Vitamin E; 8. Vitamin F ;9. Vitamin K;
- Other sites: 1. Vitamin C: The Supplement Almost Everyone Should Take When They Are Sick, a 2009 interview of Dr Ron Hunninghake (7f) 2. Rhonda Patrick discusses Vitamin C on Mercola (7j)
NOTE: Consult with your health practitioner before taking any supplements. Overuse of supplements, just as overuse of drugs, can lead to other health problems, and some supplements can interact negatively with other supplements or drugs.
Remember that the best way to get your vitamins, minerals and other nutrients is from fresh whole foods.
See Vitamins: Intro for
- Introduction: Vitamins
- Vitamin Supplementation vs Whole Foods
Check out: article on Weight Loss Resources website (UK) (8).
Food Sources, Dosage and Toxicity of Vitamin C
Fruits and vegetables are the main sources of vitamin C. Good sources include blackcurrants, berries, green leafy vegetables like Brussels sprouts, cabbage, spinach and broccoli, tomatoes, peppers, kiwi fruit, citrus fruits and their juices. Here’s a sampling indicating vitamin C content (8):
- ½ red pepper: 112 mcg
- 200 ml (6.8 fluid oz) glass of orange juice: 78 mcg
- 100 g (3.5 oz) fresh strawberries: 77 mcg
- 90 g (3.2 oz) boiled broccoli: 40 mcg
- 1 kiwi fruit: 35 mcg
- 1 tomato: 14 mcg
Healthful meals are comprised of whole foods as much as possible, especially fresh (or home canned/frozen) organic or biodynamic foods grown by someone you know. It means avoiding prepared and processed foods (commercially canned, bottled, frozen), and especially avoiding foods made with highly processed or artificial ingredients. Know your ingredients; know your cook. For more, refer to my articles:
- Diet for Health;
- Whole Foods: What they Are, Which Are Not;
- Whole Foods Signatures;
- Whole Foods: Local vs Organic; Procuring Healthful Foods.
Minimal Vitamin C dosages range from 500 mg. – 2000 mg; therapeutic dosages range from 2000 mg. – 30 grams (30, 000 mg). (14) “Oral megadosing is best done before meals and at bedtime. Four to five doses a day can total 20, 3O or 40 grams.” (15f)
However, Vitamin C should never be taken with aspirin as aspirin has been shown to block the effect of Vitamin C. If you need to take both, simply separate them by a few hours.
There are two forms of Vitamin C: acidic (ascorbic acid and liposomal vitamin C). and buffered (ascorbates, such as sodium or calcium ascorbate). When to take (note: I lost the source link for this; I hope I don’t recall it backwards):
- Acidic forms (Ascorbic acid and liposomal vitamin-C) are best taken after/away from a meal;
- Buffered forms (such as sodium or calcium ascorbate) are best taken with a meal. Because buffered ascorbic acid is nearly neutral in pH, it should not interfere with the stomach’s acidity needed for proper digestion.
Liposomal Vitamin C
This is a form of acidic vitamin C that is encapsulated in a phospholipid layer. However, Mercola’s “Liposomal Vitamin C” is not in the liposomal form; rather it is acidic vitamin C combined with phospholipids in a capsule; this combination helps “protect the vitamin C and aid in the formation of liposomes in the stomach.” (7g) As of this update (3/26/20), I take 1 – 2 capsules daily; however if I experience symptoms of the new coronavirus (COVID-19), I will take 3 daily, after meals.
See also Mercola’s sales-pitch for his Liposomal Vitamin C (7h) for lots of additional information.
Because Vitamin C is water soluble it is generally considered non-toxic. However, people can avoid gastric discomfort if they take the buffered form (ascorbate, rather than ascorbic acid). (14)
Benefits and Risks of High-Dose Vitamin C
Here are just a few of the benefits it provides (11b, 7j unless noted otherwise); much of these benefits are supported by research:*
- Accelerates repair and regeneration process of tissues;
- Antioxidant abilities
- Protect nutrients such as proteins, lipids and even DNA and RNA in your body from reactive oxygen species;
- May help decrease risk of neurodegenerative conditions like Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and multiple sclerosis because it reduces oxidative damage
- Research indicates Vitamin C protects cells from the damaging effects of oxyradical, helping to protect immune cells from incurring damage, and may promote the production of interferon, which helps defend against viruses.
- Avoid eye problems such as cataracts (13);
- Can help combat different types of cancers.
- Coronavirus (COVID-19) and related diseases: High doses of intravenous Vitamin C slows down the spread of the new coronavirus, and to help those who already have the disease, to heal. See Vitamin C vs. Viral disease section, below.
- Helps in iron absorption in the body;
- Improved immune system;
- May promote the production of interferon, which helps defend against viruses.
- Neutralizes the effects of nitrites found in packaged food and which are classified as “probably carcinogenic by the International Agency for the Research of Cancer (IARC).” (13)
- Reduces risk of heart attack by decreasing triglycerides and LDL cholesterol [Cat’s note: Being a risk factor is not the same as being a cause of a particular disease];
- Reduced symptoms of cold/flu. Research suggests that using vitamin C prophylactically as well as therapeutically at the onset of cold symptoms may reduce symptoms and cold duration
See also Mercola’s article: Vitamin C: The Supplement Almost Everyone Should Take When They Are Sick, a 2009 interview of Dr Ron Hunninghake (7F) and Rhonda Patrick’s article (7j)
- Bioavailability of vitamin C varies by form; intravenous is most bioavailable, but liposomal vitamin C, in which vitamin C is encapsulated in a lipid particle, may increase bioavailability of oral vitamin C considerably
High-dose vitamin C has some risks: (12)*
- “In patients with a history of kidney disorders, kidney failure has been reported after ascorbic acid treatment. Patients with a tendency to develop kidney stones should not be treated with high-dose vitamin C.
- Case reports have shown that patients with an inherited disorder called G-6-PD deficiency should not be given high doses of vitamin C, due to the risk of hemolysis (a condition in which red blood cells are destroyed).
- Since vitamin C may make iron more easily absorbed and used by the body, high doses of the vitamin are not recommended for patients with hemochromatosis (a condition in which the body takes up and stores more iron than it needs).”
‘* NOTE: the article does not provide its references.
Vitamin C and Coronavirus (COVID-19)
See my “Notes on natural health/healing topics: A – C” post; scroll down to “Coronavirus (COVID-19) and Vitamin C” topic. This could also apply to other respiratory illnesses such as colds and influenza.
Effect of Vitamin C on Blood Pressure
High blood levels of vitamin C have been linked to lowered blood pressure, both cystolic and diastolic by several studies, the most recent of which was “Vitamin C in plasma is inversely related to blood pressure and change in blood pressure during the previous year in young Black and White women,” published in Nutrition Journal, December 17, 2008 (3H).
This effect is attributed to the vitamin’s antioxidant ability, destroying free radicals in the blood stream that could otherwise lead to high blood pressure. (Mercola article (7E), Reuters article (9)) .
Mercola (7E) points out that increased intake of vitamin C is NOT THE CURE for high blood pressure, but it can provide some protection while you work on what he believes is the real cause of elevated blood pressure: elevated blood insulin resulting from insulin resistance: “Groundbreaking research published in 1998 in the journal Diabetes reported that nearly two-thirds of the test subjects who were insulin resistant also had high blood pressure.”
Vitamin C vs. Viral disease & toxic poisoning
2020 update: China recommends intravenous High-dose vitamin C for treatment of the new Corona virus, COVID-19. Corona virus is a group of respiratory viruses that cause colds and flu, with COVID-19 being the new one that originated in China. From Green Med Info (15e):
“The government of Shanghai, China has announced its official recommendation that COVID-19 should be treated with high amounts of intravenous vitamin C. (1) Dosage recommendations vary with severity of illness, from 50 to 200 milligrams per kilogram body weight per day to as much as 200 mg/kg/day.”
Ultra-high doses of vitamin C have been demonstrated to produce remarkable cures for viral diseases. See video news program “Living Proof – Vitamin C Miracle Cure” from New Zealand about miraculous recovery of man from flu-related pneumonia after such intravenous treatment, and the legal lengths the family had to pursue to get the hospital to try this unconventional treatment. (10)
Dr Tom Levy is a leading researcher in this field. From “Benefits of IV VitaminC,” by Dr. Thomas Levy (11A; replaces the original link for “Benefits of Intravenous Vitamin C” by Dr Levy that is no longer valid).
“In a nutshell, it has to do with electron flow; vitamin C is an electron donor, providing flow to stop rampant oxidation in its tracks, giving the body a chance to reverse oxidative damage. Compromised electron flow is a sure sign of disease. “One conclusion that can be reached from this information is simple, elegant, and very compelling: All toxins poison by oxidizing enzymes and tissues.”
See a pdf of a powerpoint presentation by Dr. Levy: “Vitamin C: The Facts, The Fiction, and The Law” (11C). [NOTE: The Law part is targeted for residents of New Zealand, but it would be wonderful if all countries had similar protections.] Examples of diseases cured by vitamin C as listed in the powerpoint:
- acute hepatitis,
- viral encephalitis,
- rheumatic fever,
- toxic mushroom poisoning,
- west nile virus,
- hemorrhagic Dengue fever,
- coronary artery disease.
Dr Levy asserts that vitamin C has no known toxic dosage in patients without preexisting kidney disease, and does not increase risk of kidney stones.
Cat’s note to self: I have saved a copy of Dr. Levy’s pdf at CATSFORK > PDF FILES / Vitamin-C-DrLevy_NZ_Sept2009.pdf
Vitamin C vs. Cancer
- Recent studies indicate intravenous or high-dose liposomal Vitamin C is a powerful agent against certain cancers, by blocking the cancerous stem cells from multiplying (7A) NOTE: Dietary vitamin C will not have the same beneficial effect as IV or liposomal forms.
- blood cancer, including acute and chronic leukemia
- pancreatic, colon, liver and ovarian cancers
- It also improves the effectiveness of chemo and radiation treatments when administering it with the treatments.For example, a study on patients undergoing radiation treatments for glioblastoma brain cancer. “half of the people in the study were alive nearly two years later. The average survival for the disease is generally around a year.” (7B)
- Used in combination with nutritional ketosis and fasting prior to administering chemo radically improves the effectiveness of chemotherapy. (7B, 7C) See my article Cyclical Ketogenic Diet (CKD) and Metabolic Mitochondrial Therapy (MMT) for more about nutritional ketosis and fasting.
- IV or liposomal Vitamin C treatment also:
- lowers chronic inflammation, a hallmark of cancer;
- lowers the risk of metastasis;
- helps improve symptoms associated with cancer and cancer treatment, such as fatigue, nausea, vomiting, pain, loss of appetite and overall quality of life.
Vitamin C, Hormones, and Cancer
See also “Vitamin C vs Cancer” section above; The following is from Green Med Info (15a).
“The molecular structure of progesterone, estrone (a form of estrogen) and testosterone is such that when exposed to differing biological and/or environmental conditions, e.g. UV light, pH, temperature, they lose electrons, becoming toxic and often carcinogenic metabolites that represent a burden on the body’s eliminative capabilities.”
Vitamin C donates electrons to these hormones, thus regenerating the original hormones and detoxifying the carcinogenic metabolites. In the cited research article from 1993 (3i), “vitamin C was capable of almost complete regeneration of estrone and quite significant regeneration of both progesterone (52.7%) and testosterone (58.6%).”
Treatment with vitamin C for these issues, often requires high-doses (via IV). Fortunately, vitamin C is “exceptionally safe at high doses and has hundreds of proven health benefits (view [Green Med Info’s] Vitamin C health benefit database (15b)), whereas conventional chemopreventive agents for cancer, e.g. Tamoxifen (15c), and hormone replacement therapy (15d) using animal derived and/or synthetic hormone analogs, cause a wide range of adverse health effects, including at times increased mortality.”
References (for vitamin C):
- (6) dailyyonder.com/four-food-groups/2010/03/04/2623
- ncbi abstracts (3B – 3G originally cited in Supplements for Insulin Resistance, as numbers 21A – 21F)
- (new) ncbi.nlm.nih.gov/pubmed/23183291
- (21A in Supplements for IR) ncbi.nlm.nih.gov/pubmed/7622343
- (21B) ncbi.nlm.nih.gov/pubmed/6278902
- (21C) ncbi.nlm.nih.gov/pubmed/22986984
- (21D) ncbi.nlm.nih.gov/pubmed/9169302
- (21E) ncbi.nlm.nih.gov/pubmed/3017301
- (21F) ncbi.nlm.nih.gov/pubmed/8131066
- (9A) ncbi.nlm.nih.gov/pubmed/19091068 for Nutrition Journal, December 17, 2008 on PubMed
- Selene River Press, by and about Dr Royal Lee, regarding Dr W. A. Price’s XFactor:
- Dr Royal Lee’s original article on Dr Weston A. Price’s XFactor: seleneriverpress.com/historical/dr-royal-lee-on-the-x-factor-of-dr-weston-a-price/; or see the original article: 6sd6hj41ya-flywheel.netdna-ssl.com/images/pdfs/40_weston_price_vitamin_f.pdf (I’ve also saved it as a pdf: CATSFORK > PDF FILES / Price-VitaminF-XFactor_Dr RoyalLee.pdf)
- Butter, Vitamin E, and the X-Factor (historical archive of Dr Lee’s article) (seleneriverpress.com/historical/butter-vitamin-e-and-the-x-factor-of-weston-a-price/)
- Lectures of Dr. Royal Lee, Vitamin News (seleneriverpress.com/shop/lectures-of-dr-royal-lee-volume-i-pdf-ebook/
- Vitamin News, a collection of all the biannual issues in one book: (seleneriverpress.com/shop/vitamin-news/
- Article on The X-Factor of Dr. Weston A. Price: realmilk.com/health/x-factor-vitamin-k2/
- Mercola: differences from vitamin b list begins here
- (7C) Vitamin C and leukemia and other cancer: articles.mercola.com/sites/articles/archive/2017/09/04/vitamin-c-cancer.aspx;
- (7D) articles.mercola.com/sites/articles/archive/2017/04/17/vitamin-c-improves-effectiveness-chemo-radiation.aspx;
- (7E) articles.mercola.com/sites/articles/archive/2017/03/19/metabolically-supported-therapies-cancer-treatment.aspx;
- (7F) articles.mercola.com/sites/articles/archive/2015/11/23/vitamin-c-curative-power.aspx
- (new) articles.mercola.com/sites/articles/archive/2009/01/24/lower-your-blood-pressure-with-vitamin-c.aspx
- (new) Vitamin C: The Supplement Almost Everyone Should Take When They Are Sick, a 2009 interview of Dr Ron Hunninghake (articles.mercola.com/sites/articles/archive/2010/11/20/ronald-hunninghake-on-vitamin-c.aspx
- Dr Mercola. Beware: Many Vitamin C Supplements Contain These 6 Red Flags. Learn Why Liposomal Vitamin C Is a Superior Form. Available: products.mercola.com/vitamin-c/vitamin-c-v1/.
- Reuters: High vitamin C linked to lower BP in young women
- Living Proof – Vitamin C Miracle Cure foodmatters.com/article/nz-farmer-beats-swine-flu-with-vitamin-c-60-minutes-report (original site 3news.co.nz/Living-Proof-Vitamin-C—Miracle-Cure/tabid/371/articleID/171328/Default.aspx is no longer available )
- Dr Thomas Levy articles, pdfs etc.:
- Benefits of IV VitaminC, by Dr. Thomas Levy (mymultiplesclerosis.gr/benefits-of-i-v-vitamin-c-from-dr-thomas-levy/) [The original link: qfac.com/?z is no longer valid)
- (12) nuuvohealth.com/uncategorized/benefits-high-dose-vitamin-c-iv-therapy-explained/
- pdf of a powerpoint presentation: Vitamin C: The Facts, The Fiction, and The Law; Cat’s note: I have saved a copy of Dr. Levy’s pdf at CATSFORK > PDF FILES / Vitamin-C-DrLevy_NZ_Sept2009.pdf
- International Agency for the Research of Cancer (IARC)
- Online Holistic Health: onlineholistichealth.com/vitamins-2/vitamin-2.html
- Green Med Info: