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Vitamin C

Vitamin C featured article

Background

Vitamin C, also known as ascorbic acid, is an essential nutrient, widely recognized for its antioxidant properties. These properties arise from its potent redox potential due to its capacity to donate electrons to oxidized molecules. Even in small quantities vitamin C can protect critical molecules in the body such as proteins, lipids, carbohydrates, and nucleic acids (DNA and RNA) from damage by reactive oxygen species, which are generated during normal metabolism, by active immune cells, and through exposure to toxins and pollutants (e.g., certain chemotherapy drugs and cigarette smoke). The vitamin also plays a critical role as a cofactor – a molecule that assists enzymes in chemical reactions. This dual nature of vitamin C means that it is instrumental in multiple physiological processes, including those involved in the biosynthesis of collagen, carnitine, and catecholamines. As such, vitamin C participates in immune function, wound healing, fatty acid...

Episodes

Posted on September 7th 2023 (almost 2 years)

Dr. Rhonda Patrick explores growth hormone secretagogues, spermidine's longevity role, methylene blue, whey protein, and solutions for scar tissue in a Q&A.

Posted on April 30th 2022 (about 3 years)

Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.

Posted on April 3rd 2022 (about 3 years)

In this clip, Dr. Rhonda Patrick discusses the safety and side effects of intravenous vitamin C and describes the evidence supporting its use in treating COVID-19.

Topic Pages

  • Multivitamins

    Vitamin C functions independently as a water-soluble antioxidant cofactor, merely co-formulated within multivitamin supplements without direct mechanistic synergy.

News & Publications

  • Collagen is crucial in maintaining the structural integrity of various tissues in the human body, and its decrease contributes markedly to the aging process. A recent study found that supplemental collagen combined with antioxidants substantially improved the appearance and health of skin and hair in adult women, reducing wrinkle depth by 48 percent.

    The study involved 40 healthy adult women between the ages of 38 and 50. Participants consumed a commercially available collagen treatment containing collagen, hyaluronic acid, biotin, and vitamins C and E or a placebo for 56 days. Researchers evaluated various aspects of their skin, such as elasticity, hydration, brightness, and pigmentation, along with hair strength and hair fall (normal hair loss) before, during, and after the intervention.

    They found that those who consumed the collagen treatment experienced a 48 percent reduction in wrinkle depth, a 39 percent reduction in fine lines, and a 16 percent increase in skin hydration compared to those who took a placebo. Their hair fall decreased by 28 percent versus 7 percent among those who took a placebo.

    The findings from this small study suggest that supplemental collagen and antioxidants improve skin and hair health. Collagens are characterized by a triple helix arrangement, forming a sturdy, resilient structure. They serve general tissue assembly and maintenance functions, including tissue scaffolding, morphogenesis, and repair. Learn more about collagen in our overview article.

  • Breathwork has shown promise in ameliorating oxidative stress – a driver of many chronic diseases – in healthy people and those with chronic conditions. However, scientists don’t fully understand the underlying mechanisms that drive these effects. A recent review found that breathwork promotes the activity of endogenous antioxidant enzymes.

    Researchers analyzed the findings of 10 randomized controlled trials (519 participants) investigating the effects of breathwork. The studies encompassed a range of breathwork styles and measured various biomarkers, including malondialdehyde, superoxide dismutase, glutathione, nitric oxide, vitamin C, and total antioxidant capacity levels.

    They found that participants who engaged in breathwork exhibited greater changes in the biomarkers than those who did not. In particular, breathwork increased the activity of the endogenous antioxidant enzymes superoxide dismutase and glutathione activities and decreased levels of malondialdehyde, a marker of oxidative stress.

    Breathwork is an umbrella term that refers to various breathing exercises and techniques. Evidence suggests that breathwork improves heart rate variability and promotes resilience to stress. People often engage in breathwork as part of general relaxation practices, yoga, or meditation.

    These findings suggest that breathwork reduces oxidative stress by promoting the activity of endogenous antioxidant enzymes. Only 10 studies were included in the analysis, however, so more research is needed to support the findings. Sulforaphane, a bioactive compound derived from broccoli, reduces oxidative stress, too. Learn more in this clip featuring sulforaphane expert Dr. Jed Fahey.

  • Supplemental vitamin C and arginine reduce symptoms associated with long COVID, a new study shows. People who took the combined supplements experienced less fatigue and performed better during exercise.

    Researchers gave people with long COVID either a combination of liposomal vitamin C and arginine or a placebo for four weeks. They measured their walking speed, strength, and endothelial function before and after the intervention.

    They found that those who took the vitamin C/arginine combination improved on measures of speed, strength, and endothelial function compared to those who took the placebo. They were also less likely to report experiencing fatigue.

    Vitamin C is an essential nutrient that exerts robust antioxidant properties. Evidence suggests that liposomal formulations of vitamin C are more bioavailable than conventional forms. Learn more about vitamin C in our overview article. Arginine is an amino acid that plays roles in vasodilation. Evidence suggests that arginine metabolism is altered in the setting of COVID-19.

  • Omega-3 fatty acids, folic acid, and CoQ10 reduce the risk of cardiovascular disease.

    Some nutritional components benefit cardiovascular health, but others have no effect on cardiovascular health or may even harm it, according to a recent study. Nutritional components providing the greatest benefit include omega-3 fatty acids, folic acid, and coenzyme Q10 (CoQ10), a vitamin-like compound produced in the body.

    Researchers analyzed the findings of more than 880 trials involving more than 880,000 participants that investigated the benefits of various macronutrients, micronutrients, and bioactive compounds on cardiovascular health.

    They found that the nutritional components had varied effects on cardiovascular health. For example, while omega-3 fatty acids, folic acid, and CoQ10 reduced the risk of cardiovascular disease, selenium and vitamins C, D, and E had no effect on the risk for either cardiovascular disease or type 2 diabetes (which often coincides with cardiovascular disease). On the other hand, beta-carotene (a vitamin A precursor) increased the risk of death from all causes. The researchers did not investigate the effects of the various nutritional components in combination versus alone.

    This analysis demonstrates that nutrition plays important roles in maintaining cardiovascular and metabolic health and supports the findings of large, epidemiological studies that have demonstrated that adherence to dietary patterns that are rich in omega-3 fatty acids, folic acid, and CoQ10, such as the Mediterranean Diet, for example, improves cardiometabolic health.

  • Re-analysis of landmark vitamin C trial data reveals current recommendations for intake may be too low for optimal health.

    During World War II, researchers in England conducted an experiment to determine the level at which vitamin C depletion causes scurvy, a potentially life-threatening collagen-related disorder. A re-analysis of these findings calls into question current recommendations for vitamin C intake.

    The study involved 20 healthy men who had been fed a diet providing 60 to 70 milligrams of vitamin C daily for about one month. The researchers randomly assigned the men to receive zero, 10, or 70 milligrams of vitamin C daily. Because vitamin C plays such an important role in wound healing, the researchers subjected the participants to experimental wounds and then assessed the scar strength to gauge the effects of depletion. They concluded that a dose of 10 milligrams of vitamin C daily was sufficient for optimal scar strength. The study’s findings formed the basis of public health recommendations that soon followed and, in some countries, are still observed today.

    However, the authors of the present-day article posited that the data analysis from the World War II-era study was flawed. They subjected the data to a new analysis, which revealed that the daily intake of vitamin C for providing adequate scar strength is 95 milligrams – twice the amount recommended by the World Health Organization and the National Health Service of the United Kingdom.

    These findings suggest that the landmark study on which some public health recommendations base their recommendations for vitamin C intake grossly underestimated the dose required for wound healing and optimal health. Learn more about vitamin C in our overview article.

  • People with COVID-19 have lower levels of vitamin C.

    Micronutrients – vitamins and minerals – facilitate the body’s immune responses to viral infections. Poor micronutrient status diminishes these responses and may contribute to the emergence of more virulent strains of viruses. Findings from a recent study suggest that people with COVID-19 have poor vitamin C status.

    Vitamin C is a water-soluble vitamin that plays important roles in immune function. For example, immune cells release large quantities of reactive oxygen species, often incurring damage. To protect themselves from this damage, immune cells accumulate large quantities of vitamin C, which serves as an antioxidant within the cells. Immune cells also release interferons, a class of proteins that participate in antiviral activity. Some evidence indicates that vitamin C promotes interferon production.

    The investigators collected 82 blood samples from patients with COVID-19 and healthy people. They categorized the patients according to the severity of their disease (mild, severe, critical, fatal) and measured the concentrations of various micronutrients (vitamins A, C, D, and E) in their blood samples.

    They found that the patients with COVID-19 had markedly lower vitamin C concentrations than the healthy people. Patients with the lowest concentrations tended to have longer hospital stays and were more likely to die than those with higher concentrations. The investigators did not observe similar trends for any of the other micronutrients measured. However, other research has shown that poor vitamin D status increases the risk of COVID-19 infection and severe outcomes.

    These findings demonstrate that people with COVID-19 have poor vitamin C status, which may influence the severity of their disease. Learn more about the health benefits of vitamin C in our overview article.

  • Vitamin C is an essential nutrient, widely recognized for its antioxidant properties. The vitamin protects the body from damage caused by reactive oxygen species and participates in many physiological processes, including immune function, wound healing, fatty acid metabolism, neurotransmitter production, and blood vessel formation, as well as other key processes and pathways. Findings from a new study suggest that vitamin C improves mental health and performance in young adults.

    The study investigators conducted a cross-sectional study involving 214 young adults between the ages of 20 and 39 years. They measured vitamin C concentrations in the participants' serum (the watery portion of blood). Then they conducted a randomized controlled trial involving participants whose vitamin C concentrations were considered inadequate (less than 50 micromoles per liter). Half of the participants received 500 milligrams of vitamin C twice daily for four weeks; the other half received a placebo. They assessed the participants' fatigue, attention, anxiety, and other aspects of work performance and mental health status. They also measured serum concentrations of brain-derived neurotrophic factor (BDNF), a type of neurotrophin – or growth factor – that controls and promotes the growth of new neurons.

    They found that higher serum vitamin C concentrations among participants in the cross-sectional study correlated with greater attention but had no influence on fatigue or mood. Participants who took the supplemental vitamin C had greater attention and work absorption and showed improvements in fatigue, performance, and work engagement. However, supplemental vitamin C did not influence mood or BDNF concentrations.

    These findings suggest that vitamin C benefits mental performance and health in young adults. Learn more about vitamin C in our overview article.](https://www.foundmyfitness.com/topics/vitamin-c)

  • Currently selected for this coming member’s digest by team member Melisa B.

    SARS-CoV-2, the virus that causes COVID-19, stimulates the innate immune system, causing systemic inflammation that damages the lungs. Evidence suggests that those with the most severe cases of COVID are made sicker not by increased viral replication, but by unregulated inflammation. New evidence suggests that high dose intravenous vitamin C decreases inflammation, symptom severity, and death due to COVID-19.

    Vitamin C is essential for proper immune regulation. White blood cells produce harmful chemicals to attack pathogens and carry large amounts of vitamin C to neutralize the free radicals these attacks generate. Without enough vitamin C in the body, inflammation can cause severe damage to host tissues or even death.

    The authors of the study enrolled 56 ICU patients with confirmed SARS-CoV-2 infection and severe pneumonia. They assigned participants to receive either high-dose intravenous vitamin C (24 grams per day for seven days) or a placebo (water). The authors of the study monitored the participants for inflammation, disease severity, and death.

    Participants in the high-dose intravenous vitamin C group experienced a statistically significant improvement in lung function, as measured by blood oxygen content, over seven days. They also exhibited a statistically significant decrease in blood concentrations of the proinflammatory cytokine interleukin-6. Participants with multiple organ dysfunction were less likely to die.

    High dose intravenous vitamin C therapy was found to be safe in this small pilot study, but the authors advised that further research is needed to confirm its benefits for COVID-19. These results have been shared in a preprint report, meaning they haven’t been peer reviewed yet. It is also important to note that intravenous vitamin C can result in blood concentrations that are 30 to 70 times higher than the same oral dose, so these results cannot be used to support the use of oral vitamin C supplements for SARS-CoV-2 or any other infection.

  • From the publication:

    Ascorbic acid is a known cofactor in the biosynthesis of carnitine, a molecule that has an obligatory role in fatty acid oxidation […] Ascorbic acid supplementation increased the mRNA levels of PPARα and its target enzymes involved in fatty acid β-oxidation in visceral adipose tissues. Consistent with the effects of ascorbic acid on visceral obesity, ascorbic acid not only inhibited hepatic steatosis but also increased the mRNA levels of PPARα-dependent fatty acid β-oxidation genes in livers. Similarly, hepatic inflammation, fibrosis, and apoptosis were also decreased during ascorbic acid-induced inhibition of visceral obesity. In addition, serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, and LDL cholesterol were lower in HFD-AA-fed mice than in those of HFD-fed mice.

    A few bullet points:

    • Reduced visceral obesity
    • Reduced hepatic inflammation
    • Increased expression of PPAR-a
    • Improved markers of liver health and cholesterol

    Related: studies in humans have shown reduced vitamin C status directly impacts fat oxidation in response to exercise.

  • Vitamin C is essential for the synthesis of carnitine, a compound required for fatty acid oxidation – the utilization of fatty acids as energy – commonly referred to as “fat burning.” Carnitine deficiency is associated with fatigue and poor exercise tolerance. Findings from a new study suggest that high dose vitamin C improves fatty acid oxidation.

    The two-part clinical study involved 22 men and women between the ages of 18 and 38 years. Fifteen of the participants had marginal vitamin C blood levels (less than 34 micromoles per liter) and seven had adequate vitamin C blood levels (greater than 34 micromoles per liter).

    In the first part of the study, all of the participants completed a 60-minute treadmill walk at 50 percent of their VO2 max. Fat utilization during the treadmill walk was 25 percent lower among participants with marginal vitamin C status, suggesting that vitamin C status affects fuel utilization during exercise.

    In the second part of the study, the participants' vitamin C levels were depleted over a period of four weeks. Then they took either 500 milligrams of vitamin C or a placebo every day for four additional weeks. At the end of the eight-week period, the average blood vitamin C levels in the supplemented group were 41.7 micromoles per liter, but average levels among the depleted group were 9.7 micromoles per liter. Fatty acid utilization in the supplemented group was approximately four times greater than the vitamin C depleted group. Poor fatty acid oxidation during exercise was related to higher levels of fatigue.

    These findings suggest that low vitamin C status is associated with poor fatty acid oxidation during exercise and may explain why some people are unsuccessful when trying to lose weight.

  • According to animal research, even mild vitamin C deficiency may impact fetal hippocampal development, a part of the brain crucial for learning and memory.

    From the article:

    “Even marginal vitamin C deficiency in the mother stunts the fetal hippocampus, the important memory centre, by 10-15 per cent, preventing the brain from optimal development,” says Professor Jens Lykkesfeldt.

    […]

    “People with low economic status who eat poorly – and perhaps also smoke – often suffer from vitamin C deficiency. Comparatively speaking, their children risk being born with a poorly developed memory potential. These children may encounter learning problems, and seen in a societal context, history repeats itself because these children find it more difficult to escape the environment into which they are born,” says Jens Lykkesfeldt.

    From an earlier study’s press release:

    Guinea pigs subjected to moderate vitamin C deficiency have 30 per cent less hippocampal neurones and markedly worse spatial memory than guinea pigs given a normal diet. […] The highest concentration of vitamin C is found in the neurons of the brain and in case of a low intake of vitamin C, the remaining vitamin is retained in the brain to secure this organ.

    Vitamin C deficiency is widespread and may impact early development:

    In some areas in the world, vitamin C deficiency is very common – population studies in Brazil and Mexico have shown that 30 to 40 per cent of the pregnant women have too low levels of vitamin C, and the low level is also found in their foetuses and new-born babies.

  • From the article:

    Scientists treated both normal mice and mice with a mutation in the gene responsible for Werner’s syndrome (WRN gene) with vitamin C in drinking water. Before treatment, the mice with a mutated WRN gene were fat, diabetic, and developing heart disease and cancer. After treatment, the mutant mice were as healthy as the normal mice and lived a normal lifespan. Vitamin C also improved how the mice stored and burned fat, decreased tissue inflammation and decreased oxidative stress in the WRN mice.

    From actual publication, rather than press release:

    Daily ascorbate supplementation allowed [Werner mice] to recover a normal mean life span and healthy aging. Although the number of animals used in each cohort was not big enough for a statistical testing on maximum life span, ascorbate treatment did prevent the appearance of Werner syndrome characteristic redox imbalance and related genomic damage. It also prevented the liver proinflammatory status observed in [Werner mice].

    What’s someone unexpected about the fact that additional vitamin C restoring mean lifespan is the fact that Werner syndrome is associated with higher-than-usual ascorbate status rather than reduced, so supplementing with vitamin C being beneficial may be somewhat counter to expectation:

    Interestingly, blood ascorbate levels increased with phenotypic progression in [Werner mice]. Ascorbate being protective, it is possible that the retention of vitamin C is a defense mechanism to counterbalance the age‐dependent rise in oxidative stress. We cannot rule out, however, the possibility that the increased ascorbate levels observed in [Werner mice] are due to a modification in ascorbate metabolism only specific to these mice.

  • From the article:

    We now report that vitamin C supplementation can prevent some of the effects of maternal nicotine exposure on pulmonary function of offspring. […] Nicotine exposure significantly reduced forced expiratory flows, but supplementation of mothers with 250 mg vitamin C per day prevented the effects of nicotine on expiratory flows. Vitamin C supplementation also prevented the nicotine-induced increases in surfactant apoprotein-B protein.

    […]

    Prenatal nicotine exposure significantly decreased levels of elastin content in the lungs of offspring, and these effects were slightly attenuated by vitamin C. These findings suggest that vitamin C supplementation may potentially be clinically useful to limit the deleterious effects of maternal smoking during pregnancy on offspring’s lung function.

  • The human body responds to mental stress by releasing hormones called corticosteroids, triggering the body’s fight or flight response. Chronic activation of these hormones can impair immune function, increasing susceptibility to infection and disease. Findings from an early study in mice demonstrate that vitamin C mitigates the body’s stress response, thereby improving immunity.

    The authors of the study immobilized mice for an hour every day for three weeks to induce stress. They also fed the mice 200 milligrams of vitamin C daily – roughly equivalent to several grams per day in humans. A control group of mice also received vitamin C but they were not subjected to stress.

    The stressed mice that received large doses of vitamin C in their diets exhibited fewer signs of stress as evidenced by lower levels of corticosteroid hormones as well as other physical manifestations, such as weight loss. The mice also exhibited higher levels of IgG, the most abundant antibody in circulation, responsible for binding a broad selection of pathogens, including viruses, bacteria, and fungi, to prevent infection. Interestingly, the non-stressed mice that received large doses of vitamin C exhibited even greater increases in IgG, suggesting that stress cancels out some of the beneficial effects of the vitamin.

    These findings suggest that high dose vitamin C might improve immune function, especially during times of mental and physical stress.

  • From the article:

    “It’s true that vitamin C does react with oxidized lipids to form potential genotoxins,” said Balz Frei, professor and director of the Linus Pauling Institute, and co-author on this study. “But the process does not stop there. We found in human studies that the remaining vitamin C in the body continues to react with these toxins to form conjugates - different types of molecules with a covalent bond - that appear to be harmless.

    In human tests, the OSU scientists found in blood plasma extraordinarily high levels of these conjugates, which show this protective effect of vitamin C against toxic lipids.

    “Prior to this, we never knew what indicators to look for that would demonstrate the protective role of vitamin C against oxidized lipids,” Stevens said. “Now that we see them, it becomes very clear how vitamin C can provide a protective role against these oxidized lipids and the toxins derived from them. And this isn’t just test tube chemistry, this is the way our bodies work.

  • From the article:

    The researchers found that bacteria such as pneumococci release large quantities of hydrogen peroxide, and that this causes inactivation of inflammasomes thereby weakening the immune system […] Our studies demonstrate that hydrogen peroxide is an inhibitor of an important component of the inflammatory machinery suggesting that the mechanism we have uncovered is a common strategy employed by many microbes to thrive within us,“ says Saskia Erttmann, first author in the study and former member of Nelson Gekara’s research group.

    Role for vitamin C:

    “One of the best known substances with the ability to neutralize hydrogen peroxide and that could hence boost anti-bacterial immunity are vitamins such as Vitamin C found in fruits. Perhaps the old adage ‘an apple a day keeps the doctor away’ is not off the mark,” adds Nelson Gekara.

  • From the article:

    Human studies in siblings show that children born to a mother who was obese during pregnancy are at greater risk of heart disease than siblings born to the same mother after bariatric surgery to reduce maternal obesity. Such studies have provided strong evidence in humans that the environment experienced during critical periods of development can directly influence long-term cardiovascular health and heart disease risk.

    [New research] shows that adult offspring from pregnancies complicated by chronic hypoxia have increased indicators of cardiovascular disease, such as high blood pressure and stiffer blood vessels.

    […]

    The Cambridge study, led by Professor Dino Giussani, used pregnant sheep to show that maternal treatment with the antioxidant vitamin C during a complicated pregnancy could protect the adult offspring from developing hypertension and heart disease. The work therefore not only provides evidence that a prenatal influence on later heart disease in the offspring is indeed possible, but also shows the potential to protect against it by “bringing preventative medicine back into the womb,” as Dr Kirsty Brain, first author of the study, puts it.

  • From the article:

    Earlier work by UI redox biology expert Garry Buettner found that at these extremely high levels (in the millimolar range), vitamin C selectively kills cancer cells but not normal cells in the test tube and in mice.

    […]

    “In this paper we demonstrate that cancer cells are much less efficient in removing hydrogen peroxide than normal cells. Thus, cancer cells are much more prone to damage and death from a high amount of hydrogen peroxide,” says Buettner […] “This explains how the very, very high levels of vitamin C used in our clinical trials do not affect normal tissue, but can be damaging to tumor tissue.”

    Some cancers may be more vulnerable than others:

    Buettner says this fundamental information might help determine which cancers and which therapies could be improved by inclusion of high-dose ascorbate in the treatment. “Our results suggest that cancers with low levels of catalase are likely to be the most responsive to high-dose vitamin C therapy, whereas cancers with relatively high levels of catalase may be the least responsive,” he explains.

  • Inflammation is a biological response triggered by the immune system in response to a physical injury or infection. Vitamin C’s immune-boosting and antioxidant properties can mediate the body’s inflammatory response, reducing the symptoms or risk of various diseases. Evidence suggests that vitamin C can lower C-reactive protein, a marker of inflammation.

    C-reactive protein (CRP) is a protein that increases in the blood with inflammation and infection as well as following a heart attack, surgery, or trauma. It is one of several proteins that are often referred to as acute phase reactants. Blood levels of CRP greater than 1 milligram per liter are indicative of elevated cardiovascular disease risk.

    The randomized study involved nearly 400 healthy adults (average age, 44 years) who took 1 gram of vitamin C, 800 international units of vitamin E, or a placebo every day for two months. The findings revealed that vitamin E had no effect on lowering CRP; however, vitamin C supplementation decreased CRP 16.7 percent compared to pre-treatment measurements, but only in participants who had baseline CRP levels above 1 milligram per liter. This reduction in CRP was comparable to those achieved with statins (cholesterol-lowering drugs).

    Interestingly, the study identified a strong link between obesity and elevated CRP levels. Whereas 25 percent of normal-weight people had elevated CRP levels of CRP, 50 percent of overweight participants and 75 percent of obese participants had elevated levels.

    These findings suggest that vitamin C might be able to decrease inflammation to a similar magnitude as some statins in people at a higher risk of cardiovascular disease based on CRP levels.

  • Mechanical ventilation – a therapeutic measure used to assist or replace spontaneous breathing – is an important strategy used to treat people experiencing respiratory failure. A recent meta-analysis found that vitamin C treatment shortened the duration of mechanical ventilation among patients in the intensive care unit.

    The investigators looked at the findings from eight trials involving 685 patients. They found that vitamin C shortened the duration of mechanical ventilation an average of 14 percent. But the investigators noted major differences in the effect of vitamin C between the trials, with the greatest benefit observed among patients who were on mechanical ventilation for the longest duration – the patients who were most critical. In five trials involving more than 470 patients requiring ventilation for more than 10 hours, providing 1 to 6 grams of vitamin C per day shortened ventilation time an average of 25 percent.

    These findings indicate that vitamin C shortens the duration of mechanical ventilation, especially among critically ill patients.

  • From the article:

    High-dose injections of vitamin C, also known as ascorbate or ascorbic acid, reduced tumor weight and growth rate by about 50 percent in mouse models of brain, ovarian and pancreatic cancers, researchers report in the Proceedings of the National Academy of Sciences. The researchers traced ascorbate’s anti-cancer effect to the formation of hydrogen peroxide in the extracellular fluid surrounding the tumors. Normal cells were unaffected.

    Intravenous administration as a crucial differentiator:

    “Clinical and pharmacokinetic studies conducted in the past 12 years showed that oral ascorbate levels in plasma and tissue are tightly controlled. In the case series, ascorbate was given orally and intravenously, but in the trials ascorbate was just given orally. It was not realized at the time that only injected ascorbate might deliver the concentrations needed to see an anti-tumor effect,” said Levine

  • From the article:

    Vitamin C metabolism is changed in many conditions that involve physiological stress, such as infections, surgery, traumas, and burns, in which case vitamin C levels can decline dramatically. Although 0.1 grams per day of vitamin C can maintain a normal plasma level in healthy persons, much higher doses, up to 4 grams per day, are needed for critically ill patients to increase their plasma vitamin C levels to the range of normal healthy people. Therefore, high vitamin C doses may be needed to compensate for the increased metabolism in critically ill patients.

    […]

    Dr. Harri Hemilä from the University of Helsinki, Finland, and Dr. Elizabeth Chalker from the University of Sydney, Australia, carried out a systematic review of vitamin C for ICU patients. They identified 18 relevant controlled trials, and 12 of them were included in the meta-analysis on the length of stay. On average, vitamin C administration shortened ICU stay by 7.8%. In six trials, orally administered vitamin C with an average dose of 2 grams per day reduced the length of ICU stay on average by 8.6%.

  • Exercise-induced bronchoconstriction – a narrowing of the airways in response to exercise – occurs in as much as 10 percent of the general population and up to 50 percent in some fields of competitive athletics. Findings from a meta-analysis suggest that vitamin C might reduce the incidence of exercise-induced bronchoconstriction.

    Previous research demonstrated that vitamin C can triple respiratory tissue levels within an hour or two of a single oral dose of 1 or 2 grams. This local increase in vitamin C concentration appears to protect against acute increases in airway oxidative stress. In addition, vitamin C inhibits the production of prostaglandins and leukotrienes, biological compounds that participate in the pathogenesis of exercise-induced bronchoconstriction.

    In addition, vitamin C halved the incidence of the common cold among people experiencing heavy short-term physical stress – an indication that vitamin C might also have other effects on people experiencing heavy physical exertion.

    The authors of the current conducted analyses of nine studies that investigated varied aspects of the effects of vitamin C on exercise-induced bronchoconstriction. Three placebo-controlled studies analyzed the relative exercise-induced decline in forced expiratory volume, or FEV1, (a measure of respiratory capacity) with or without a vitamin C. They found that doses ranging between 0.5 and 2 grams of vitamin C reduced FEV1 decline by half. Similarly, five studies investigated the effects of vitamin C supplementation on respiratory symptoms after short-term heavy physical work and found that incidence was halved. One study investigated the duration of respiratory symptoms in young male swimmers and also found that incidence was halved.

    The authors noted that a variety of factors might influence whether and to what degree vitamin C affects respiratory function during exercise, including the type of activity and the conditions under which it is performed, among others.

  • According to animal research, even mild vitamin C deficiency may impact fetal hippocampal development, a part of the brain crucial for learning and memory.

    From the article:

    “Even marginal vitamin C deficiency in the mother stunts the fetal hippocampus, the important memory centre, by 10-15 per cent, preventing the brain from optimal development,” says Professor Jens Lykkesfeldt.

    […]

    “People with low economic status who eat poorly – and perhaps also smoke – often suffer from vitamin C deficiency. Comparatively speaking, their children risk being born with a poorly developed memory potential. These children may encounter learning problems, and seen in a societal context, history repeats itself because these children find it more difficult to escape the environment into which they are born,” says Jens Lykkesfeldt.

  • From the article:

    Miller and his colleagues reviewed and analyzed data from 29 randomized, controlled, previously published clinical trials that reported systolic and/or diastolic blood pressure values and also compared vitamin C intake to a placebo. What they found is that taking an average of 500 milligrams of vitamin C daily – about five times the recommended daily requirement – reduced blood pressure by 3.84 millimeters of mercury in the short term. Among those diagnosed with hypertension, the drop was nearly 5 millimeters of mercury.

    A comparison to common pharmacological treatment:

    By comparison, Miller says, patients who take blood pressure medication such as ACE inhibitors or diuretics (so-called “water pills”) can expect a roughly 10 millimeter of mercury reduction in blood pressure.

  • Vitamin C, which has previously been shown in some studies to reduce inflammatory markers in conditions like rheumatoid arthritis, may improve emotional state of acutely hospitalized patients.

    From the article:

    Patients administered vitamin C had a rapid and statistically and clinically significant improvement in mood state, but no significant change in mood occurred with vitamin D, the researchers discovered. […] About one in five acute-care patients in our hospital have vitamin C levels so low as to be compatible with scurvy,“ added Hoffer.

    Vitamin C, which concentrates in immune cells called neutrophils and lymphocytes at concentrations 50 to 100-times greater than plasma, play an important role in generating the so-called oxidative burst used by these cells to attack invading bacteria.

  • The bulk of scientific research on the effectiveness of vitamin C in fighting infection has centered on reducing the symptoms and duration of the common cold. Much of the studies have used doses of approximately 1 gram per day. Findings from a 2017 study suggest that larger doses might reduce a cold’s duration.

    Although most adults typically have only one or two colds per year, cold symptoms are the reason for many lost days of work or school. Some evidence suggests that the financial costs associated with having a cold are similar to those associated with having high blood pressure or a stroke.

    The author of the study reviewed the findings of two randomized trials focused on the effectiveness of vitamin C in reducing cold symptom duration. One of the trials had four treatment groups: one group that took a placebo, two groups that took 3 grams per day, and one group that took 6 grams per day. The 6-gram dose reduced cold symptom duration by about 17 percent – roughly twice as much as that observed with only 3 grams. The placebo had no effect on symptom duration. The other trial had three treatment groups: one that took 4 grams per day, one that took 8 grams per day, and one that took a placebo. Taking 8 grams per day reduced symptom duration by 21 percent, compared to the placebo group.

    These findings suggest that large doses of oral vitamin C might reduce the duration of symptoms associated with the common cold, but self-dosing should commence as soon as cold symptoms appear for the greatest benefit.

  • Sepsis is a potentially life-threatening condition caused by the body’s innate immune response to acute infection. Under some circumstances, aspects of this response that are typically associated with defense against infection can induce extensive cell and tissue damage, leading to multiple organ failure, the hallmark of sepsis. Acute respiratory distress syndrome (ARDS) is a common sepsis-associated injury that can lead to respiratory failure and death. A 2019 phase 2 trial found that intravenous vitamin C reduced death rates among patients with sepsis and ARDS.

    The randomized, double-blind, placebo-controlled, multicenter trial took place in seven medical intensive care units in the United States over a period of three years. The study participants included 167 male and female patients (average age, 55 years) with sepsis and ARDS. Every six hours for four days, the patients received either intravenous vitamin C (50 milligrams per kilogram of body weight) or a placebo.

    The authors of the study noted a substantial difference in the death rates for the two groups. Whereas approximately 30 percent of patients who received intravenous vitamin C died, more than 46 percent of patients who took the placebo died. Patients who received vitamin C also had fewer ventilated days, spent less time in intensive care (seven days versus ten), and their hospital stays were approximately one week shorter than those who received the placebo.

    These findings suggest that intravenous vitamin C administration might be beneficial in critically ill patients who have sepsis and respiratory failure.

  • Hi Rhonda,

    First off, I’m a big fan and I love your podcasts. The one thing I’m not such a fan of though, is the supplement craze.

    Do you have any comments on this study? By the looks of it, the only supplement worth taking is folic acid and B-vitamins (which is something I am considering, since I rarely eat meat).

    In my mind, if you predominantly eat plant-based wholefoods (vegetables, berries and fruits, legumes, grains, nuts and seeds in that order), molluscs every now and then (once a month-ish) (and I do eat a bit of egg and cheese on occasions), is supplementation really necessary or even desired?

    I’m a mid-twenties guy, who exercises a lot (stretching/yoga and running everyday, weights/calisthenics 3-6days/wk and intervals 2days/wk) and I strive to “optimize” my health and fitness (although I do feast on junk in social occasions every blue moon). I intermediate fast every day, every now and then I do a 2-4 day fast, and I meditate daily). Do you have any recommendations for other healthy habits I could implement? Sorry for the digression, I’d be happy with just an answer in regards to the study :)

  • Around 93% of the people receiving the intravenous vitamin C are responding to chemotherapy and radiation, compared to 40% who usually do. The intravenous vitamin C may also show encouraging results in a small sample of people with glioblastoma. Remember that oral doses of vitamin C (even liposomal) can not achieve the same plasma concentrations that IVC can, which are between 800 to 1,000-fold higher. Other studies have revealed mechanisms by which the IVC works including the production of hydrogen peroxide which selectively kills cancer cells. Normal cells can detoxify the hydrogen peroxide but cancer cells cannot. The IVC also inhibits glucose from being taking up into the cancer cells since it competes for binding to glucose transporters. The multitude of both animal studies and clinical studies on intravenous vitamin C seem like it may be a very promising cancer treatment particularly with the standard of care treatment. I look forward to seeing the results of larger trials.

  • High-dose intravenous vitamin C has previously been shown to selectively kill cancer cells by increasing hydrogen peroxide and now it has been found to potently kill cancer stem cells. The new study screened a variety of compounds in order to find those that were most potent at killing cancer stem cells, which are the most resistant to any type of cancer treatment. Interestingly, vitamin C was found to be 10 times more potent at killing cancer stem cells (cultured in a dish) than 2-deoxyglucose, a drug that prevents cancer cells from using glucose via glycolysis. While this study was done in a culture dish, other studies have been done in animals and humans. It is important to realize that intravenous vitamin C increases blood levels that are 100-500 times higher than levels that can be achieved with oral ingestion. It is this VERY-high concentration of vitamin C in the blood that results in the generation of hydrogen peroxide that selectively kills cancer cells because normal cells effectively remove it but cancer cells cannot. Also, early phase 1 clinical trials showed that the combination of high-dose, intravenous vitamin C with standard chemotherapy or radiation was well tolerated and improved patient outcome. Larger clinical trials are now underway.

  • I also want to add that while vitamin C is considered an antioxidant it does not act the same as other antioxidants such as vitamin E and NAC, which have actually been shown to accelerate tumor growth. Vitamin E and NAC can sequester reactive oxygen species (which activates cancer cell death) and prevents cancer cells from dying. Vitamin C does not act the same way. This is why it is VERY important to understand mechanisms and not make generalizations. Vitamin C is in constant homeostasis between oxidized and reduced forms and this depends on many factors including dose. When administered intravenously, the vitamin C dose is so high that it forms the oxidized form and this does a couple of important things that can kill cancer cells. First, it causes oxidative stress in cancer cells (a well known mechanism to activate cell death of a cancer cell). Second, it inhibits the glycolysis pathway, thus starving cancer cells of glucose.

  • Catechins are bioactive compounds present in green tea. One well-known catechin, epigallocatechin gallate (EGCG), is a potent scavenger of reactive oxygen species and has demonstrated antioxidant, anti-inflammatory, and anticarcinogenic properties in both clinical and in vitro studies. Some evidence suggests that adding vitamin C to green tea might increase the bioavailability of the catechins present in green tea.

    Consumers of green tea commonly add milk, lemon, or other substances to their tea. To assess the impact that these additives have on catechin bioavailability, the authors of the study added varying quantities of citric acid, BHT and EDTA (common preservatives), ascorbic acid (vitamin C), milk (cow’s, soy, and rice), and citrus juice (orange, grapefruit, lemon, and lime) to prepared tea. Then they subjected the tea formulations to simulated digestive processes and measured the amount of catechins they recovered.

    They found that overall, green tea catechin recovery was poor, with more than 80 percent loss of catechins during digestion. Adding milk to tea increased catechin recovery considerably, but the greatest improvements were observed with the addition of vitamin C or citrus juices, the latter of which increased recovery to 98 percent.

    Citrus juices contain bioactive compounds that might influence catechin recovery, but they are also rich in vitamin C. These findings suggest that consumption of green tea with vitamin C, especially in conjunction with other bioactive compounds in citrus juices, increases the recovery of the beneficial components present in the tea.