Why 500 mg Isn’t High Dose and What the

Figure 1. Plasma vitamin C concentration measured by finger-prick sampling on a dosing day (Sept 26, 2022, three oral doses of sodium ascorbate totaling 14.7 g) versus a no-supplementation baseline (Sept 27, 2022). Plasma levels sustained well above 200 µM throughout the day with split dosing. Preliminary unpublished data, M.S. Donaldson; full publication forthcoming.

There are a couple of takeaways from the graph here:

1. You can keep vitamin C levels elevated by taking multiple doses throughout the day. Every three or four hours is about the right amount of time between doses.
2. Vitamin C concentrations can be achieved that are clinically meaningful for therapeutic endpoints.
3. The doses you need to achieve these doses are safe, but are much more than you get from food.

Let me explain what the research shows when the dose is actually high enough to matter. What I achieved here, as shown in the graph above, is way more than has generally been tested in the literature. So, the results below here are really the floor, not the ceiling, of what is possible. The dose makes the therapy. 2 grams a day (1 gram in the morning and 1 gram in the evening) is not the same as 5 grams, three times a day.

Ten Conditions With Clinical Evidence for High-Dose Vitamin C

1. High Blood Pressure

Vitamin C’s effect on blood pressure comes down to nitric oxide. Endothelial cells lining your blood vessels need a cofactor called tetrahydrobiopterin (BH4) to produce nitric oxide, which relaxes arterial walls. Oxidative stress oxidizes BH4, shutting down that pathway. Vitamin C regenerates BH4 and maintains nitric oxide production.

Dr. Noyan Gokce, Dr. John F. Keaney Jr., and colleagues at Boston University School of Medicine published a randomized, double-blind, placebo-controlled trial in Circulation in 1999, testing this in 46 patients with established coronary artery disease. A single 2-gram dose of oral vitamin C improved endothelial flow-mediated dilation from 6.6% to 10.1%. That improvement held up after 30 days of 500 mg per day. Blood vessels that couldn’t dilate properly started working again.

A 2026 umbrella review by Kosari, Shahinfar, and colleagues covering 17 randomized controlled trials, published in Food and Function, found that vitamin C supplementation reduced systolic blood pressure by an average of 3.7 mmHg. In people with diabetes, diastolic blood pressure dropped 2.3 mmHg. A 2023 meta-analysis by Lbban, Kwon, and colleagues in the International Journal of Food Sciences and Nutrition confirmed a 4.6 mmHg systolic drop in diabetic patients specifically. The effect is strongest in people where oxidative stress is driving the dysfunction. The median dose in these studies was 750 milligrams, so not exactly a megadose.

A 3- to 5-point drop in systolic pressure isn’t dramatic for one person. But if you got a 3- to 5-point drop for everyone in the population, it corresponds to a 10-15 percent reduction in overall stroke risk. That would be a significant benefit. But that’s not all. You can stack vitamin C with other interventions, like high-nitrate vegetables. See our article on How to Lower Blood Pressure Naturally: 10 Foods That Work for a full rundown. By stacking these nutritional interventions, you can achieve a much greater effect on blood pressure than any single approach can on its own.

2. Cancer: Adjunct Therapy

A cancer diagnosis is an all-hands-on-deck kind of emergency. We don’t recommend a minimalist approach. We bring to bear all our tools to boost immune function and to reverse the metabolic conditions in which cancer thrives. That’s true of functional medicine practitioners and integrative medicine doctors as well. And intravenous vitamin C is one of their most powerful tools. Rather than just advocating for vitamin C therapy, let’s look honestly at what the evidence supports and doesn’t support. High-dose intravenous vitamin C is being studied as an adjunct to conventional cancer therapy, not as a replacement for it. It is not used as monotherapy for cancer.

At IV concentrations above 1,000 micromolar, vitamin C generates hydrogen peroxide inside tumor cells through a pro-oxidant mechanism. This selectively damages cancer cells while leaving healthy tissue unharmed. A 2026 review by Zhao, Fu, Yang, and colleagues at Chongqing Medical University in Genes and Diseases confirmed safety in phase I and II clinical trials and reported promising survival data in adjuvant pancreatic cancer trials. 

The history here is worth knowing. Dr. Ewen Cameron and Dr. Linus Pauling published trials in 1976 in PNAS showing that high-dose IV vitamin C extended survival in patients with terminal cancer. The Mayo Clinic tried to “replicate” those results using oral vitamin C and failed. For years, that was used to dismiss the whole field.

The Levine group at NIH resolved that apparent contradiction in 2004: oral and intravenous vitamin C produce fundamentally different plasma concentrations. Cameron and Pauling were using IV. The Mayo Clinic was using oral. They were testing different interventions, not replicating the same one. I wonder if they also knew that back in 1976, though I don’t have proof of that theory.

A January 2026 systematic review by Alangari, Arif, and colleagues in the Journal of Medicine and Life reviewed the full body of RCT evidence. It documented immune-modulation effects, including suppression of STAT1 and PD-L1 inflammatory pathways, reduced chemotherapy-related toxicities, and improved quality of life in palliative care. Three smaller trials showed reductions in organ dysfunction and mortality benefits in sepsis. Five larger combination therapy trials showed no difference. There are some real benefits to IV vitamin C, but exactly how to do it and who benefits most from it are still being worked out. You may want to speak with an integrative oncologist about your specific situation.

3. Type 2 Diabetes and Blood Sugar Control

Most people don’t realize this: glucose and vitamin C compete for entry into cells through the same GLUT transporters. When blood sugar is chronically elevated, vitamin C gets crowded out. Ironically, the cells that need it most (immune cells, the adrenal glands, the lens of the eye) become depleted even when dietary intake looks adequate. This is one reason why high blood glucose is so dangerous.

A 2023 systematic review and meta-analysis by Nosratabadi, Ashtary-Larky, and colleagues covering 22 randomized controlled trials in 1,447 people with type 2 diabetes, published in Diabetes and Metabolic Syndrome, found that supplementation at 1,000 mg or more per day significantly reduced HbA1c, fasting blood glucose, and fasting insulin. The high-dose subgroup also significantly reduced HOMA-IR, a direct measure of insulin resistance.

A 1995 study published in the Annals of Nutrition and Metabolism by Drs. Eriksson and Kohvakka at the University of Tampere used 2,000 mg per day in type 2 diabetics. After 90 days, fasting blood glucose fell from 12.7 to 10.0 mmol/L. Post-meal glucose dropped from 16.5 to 11.7 mmol/L. Even with results like these, vitamin C is rarely mentioned as a nutritional therapy for diabetes. Unreal.

4. Immune Function and Infections

Vitamin C concentrates in white blood cells at levels 50 to 100 times higher than plasma. That’s not a coincidence. Immune cells consume vitamin C rapidly during active infection, and plasma levels drop during illness even without any change in what you’re eating. It seems like arming your immune system’s warriors would be a good thing.

Dr. Harri Hemila at the University of Helsinki has spent decades studying vitamin C and reviewing this literature. His 2017 narrative review in Nutrients covers 148 animal studies showing vitamin C alleviated or prevented infections from bacteria, viruses, and protozoa. In humans, it tells a nuanced story.

Regularly administered vitamin C does not reduce the incidence of colds in the general population. But it halved the number of colds among people under heavy physical stress (marathon runners, military recruits during winter exercises, schoolchildren at ski camps). And there’s a dose-response for duration: 1 gram per day shortened cold duration by 8% in adults, 18% in children. At 6 to 8 grams per day, the evidence for shortening duration becomes stronger.

Here’s the part of this history that most people don’t know. Three papers published in 1975, by Chalmers, by Karlowski and colleagues, and by Dykes and Meier, effectively killed research interest in vitamin C and the common cold for 30 years. Those papers were cited in medical textbooks and national health recommendations as proof that vitamin C doesn’t work.

They were methodologically wrong. Hemila documented the errors thoroughly. Chalmers pooled studies using doses as low as 25 milligrams. Karlowski’s data showed a dose-response benefit, but the authors attributed the effect to the placebo. Dykes and Meier presented no quantitative analysis at all. None of these papers justified the sweeping conclusion that vitamin C is ineffective against infections. The damage from that conclusion, however, lasted for a generation.

Dr. Tom Levy, a cardiologist and attorney, has also written extensively on this topic. His book Vitamin C: Infectious Diseases and Toxins is a comprehensive treatment of the clinical history of using vitamin C to treat infections. It’s worth reading if you want the full picture of what was learned before the dismissals of the 1970s took hold.

For more on how vitamin C fits into a complete immune support protocol, see our immune function webinar, where this is a centerpiece of the discussion.

5. Sepsis and Critical Illness

Vitamin C levels crash in critically ill patients. Sepsis patients commonly arrive with plasma levels near zero, even if their diet was adequate before admission. The oxidative stress load of systemic infection is simply overwhelming.

Dr. Paul Marik at Eastern Virginia Medical School published a retrospective before-after study in Chest in 2017 that stopped the critical care world in its tracks. He treated 47 sepsis patients with intravenous vitamin C, hydrocortisone, and thiamine. Hospital mortality was 8.5% in the treatment group compared to 40.4% in the control group. Every patient in the treatment group came off vasopressors within 18 hours on average. None developed progressive organ failure.

The controversy that followed is still ongoing. Other groups have tried to replicate Marik’s results in larger trials and have not consistently seen the same mortality benefit. The current understanding is that hydrocortisone may drive vitamin C into cells more effectively, enhancing its action in ways that make the combination more potent than vitamin C alone. Whether the specific protocol, dose, timing, or patient selection accounts for the different results in replication attempts is not yet settled.

Here is what we do know: the biological rationale is strong, the safety profile of IV vitamin C is excellent, and the clinical signals are real enough that the research continues. Dr. Alpha Fowler at Virginia Commonwealth University published a randomized controlled trial in JAMA in 2019 testing 200 mg per kg body weight of IV vitamin C per day for four days. Organ failure scores fell significantly. 28-day mortality dropped from 46% to 30%. But mortality at 28 days was not a primary outcome in this trial and was not mentioned in the study’s abstract. In fact, the abstract makes it seem like vitamin C was ineffective in treating sepsis. Note that JAMA is a magazine published by the AMA for doctors. Go figure.

6. Trauma and Surgery

Major trauma and surgery create an acute oxidative stress burden that can drop plasma vitamin C to near-scurvy levels within hours. Burn patients lose vitamin C directly through wound exudate.

Dr. Bryan Collier and colleagues at Vanderbilt University Medical Center implemented a protocol in their trauma center using 1,000 mg of IV vitamin C every 8 hours, plus vitamin E and selenium. The results, published in the Journal of Parenteral and Enteral Nutrition in 2008, were striking. Patients on the antioxidant protocol had a 28% lower risk of death and significantly shorter hospital and ICU stays. Patients with an expected survival below 50% had a 76% lower risk of death. The effect was strongest among those who were most severely injured.

This is one of the mechanistically tightest cases for high-dose vitamin C. The need is measurable and acute. The deficiency is well-documented. The biological connection between collagen synthesis, immune function, and tissue repair is directly relevant to the outcome being measured.

7. Cardiovascular Disease

Beyond blood pressure, vitamin C protects the cardiovascular system by preventing LDL cholesterol from oxidizing. Oxidized LDL is what actually damages arterial walls and initiates atherosclerotic plaques. Unoxidized LDL is comparatively benign.

Dr. Balz Frei at the Linus Pauling Institute at Oregon State University published foundational research in PNAS showing that vitamin C at concentrations achievable through supplementation inhibits LDL oxidation in plasma. Their research showed that vitamin C is the preferred antioxidant in blood for preventing LDL oxidation. Nothing else substituted for vitamin C, and even very high levels of vitamin C never became pro-oxidant in the blood, which has been confirmed many times by IV vitamin C infusions.

The Gokce and Keaney trial discussed in the blood pressure section above directly demonstrated that 2 grams of vitamin C restored endothelial function in patients with established coronary artery disease, with the effect maintained at 500 mg per day over the long term.

8. Bone Health and Collagen Synthesis

Vitamin C doesn’t just support collagen. It’s required for collagen synthesis. Not just helpful, but required. The enzymes that cross-link collagen fibers (prolyl hydroxylase and lysyl hydroxylase) cannot function without it. Collagen makes up roughly 30% of bone by weight. The mineral matrix deposits on that collagen scaffold. Without adequate vitamin C, the scaffold weakens regardless of how much calcium you’re taking in.

Population studies consistently find higher bone mineral density in people with higher vitamin C intake. Scurvy is the extreme case, where collagen falls apart and old wounds literally reopen. Subclinical insufficiency is more common than most people recognize, particularly in older adults, smokers, and anyone with chronic illness. See our article on vitamin C and bone health for the full breakdown.

9. Skin Health and Anti-Aging

The skin connection is the most visible expression of vitamin C’s role in collagen synthesis. The dermis is largely collagen. UV radiation depletes skin vitamin C directly, which is why sun-exposed skin ages faster than protected skin, even in people with good dietary habits.

Higher plasma vitamin C levels are consistently associated with reduced skin wrinkling, better wound healing, and improved hydration. Topical vitamin C has its own evidence base, but oral supplementation raises plasma levels, supplying the skin from within. That’s a different and complementary mechanism. See our article on vitamin C and skin health for the specific evidence on doses and outcomes.

10. Exercise Recovery and Muscle Soreness

Intense exercise produces oxidative stress in muscle tissue. That oxidative burst is part of the training adaptation signal, but it also drives delayed onset muscle soreness (DOMS) and slows recovery. Vitamin C helps neutralize that exercise-induced oxidative damage.

Dr. Chun-Chung Chou, Dr. Yu-Chi Sung, and Dr. Glen Davison studied how short-term high doses of vitamins C and E affect muscle damage in athletes. They either gave a placebo or 2,000 mg of vitamin C and 1,400 IU of vitamin E daily for four days to elite Taekwondo athletes. The results showed that this combo helped reduce muscle damage and inflammation during matches, as seen through lower levels of muscle damage markers. The study suggests that short-term antioxidant use can aid in recovery without affecting performance. So, take vitamin C a few days before a strenuous workout or your long weekend project to aid recovery.

Forms of Vitamin C: An Honest Comparison

The supplement market sells vitamin C in at least half a dozen forms with claims that can be hard to evaluate. Here’s what the evidence actually supports.

Ascorbic Acid

This is standard vitamin C. When you see ascorbic acid on a label, you’re getting the molecule your body uses. The issue at high doses is that it’s an acid. Taking 3,000 mg of ascorbic acid at once is likely to cause stomach discomfort and loose stools in most people. That’s not toxicity. It’s a stomach pH issue that limits how much you can take at one time. The reason the tolerable upper limit (TUL) for vitamin C is 2,000 milligrams a day is because of stomach discomfort and loose stools in some people. It’s not a toxicity issue at all. 

Standard vitamin C does not dissolve very well in water either, so it’s not as easy to use. It’s okay in capsules and tablets, but for high doses, this isn’t the form you want. 

The way to use ascorbic acid, if that is what you have available, is to take 1 g per hour as a tablet or capsule. That works quite well as the acid is spread out.

Sodium Ascorbate (What We Recommend)

Sodium ascorbate is ascorbic acid buffered with sodium to a neutral pH. Your body uses it identically. The difference is tolerability and dissolvability. Sodium ascorbate is far gentler on the stomach at high doses, so you can take more without the digestive side effects that make people stop. One teaspoon of our Vitamin C Powder (Sodium Ascorbate) provides 4,400 mg of vitamin C in a form your gut handles comfortably. The sodium content (around 450 mg per teaspoon) is worth noting if you’re managing sodium intake carefully. Sodium ascorbate also dissolves very well in water, juice, or smoothies, with only the taste of salt, so it is much easier to use than ascorbic acid.

Liposomal Vitamin C

Liposomal vitamin C encapsulates ascorbic acid in phospholipid spheres to improve absorption. The evidence supports a real but modest advantage. Clinical trials consistently show liposomal vitamin C is roughly 1.3 to 1.8 times more bioavailable than standard oral vitamin C at equivalent doses, measured by peak plasma concentration and total exposure. There’s also evidence of better uptake into white blood cells specifically, which matters for immune applications. See, for example, the study by Davis and coworkers, published in Nutrition and Metabolic Insights, who tested four grams of vitamin C delivered four ways in 11 adults: oral placebo, standard oral, oral liposomal, and intravenous. Liposomal produced higher plasma levels than standard oral, but lower than IV.

So, there is a genuine benefit to liposomal vitamin C. But it’s not a dramatic one, and it doesn’t close the gap with IV. Liposomal vitamin C is significantly more expensive than sodium ascorbate. For most people pursuing high-dose supplementation, well-timed divided doses of sodium ascorbate produce comparable sustained plasma levels at a fraction of the cost. That’s the honest comparison.

Intravenous Vitamin C

IV vitamin C is in a different category entirely. It bypasses the intestinal absorption ceiling and produces plasma concentrations 50 to 100 times higher than any oral form can achieve. This is what makes it a serious tool in cancer adjunct therapy and critical illness. The plasma levels needed to generate the pro-oxidant, tumor-selective hydrogen peroxide mechanism require IV administration.

IV vitamin C is a clinical intervention, not a supplement. It requires medical supervision, a clinical setting, and appropriate screening. G6PD deficiency testing in particular is essential because IV vitamin C can trigger hemolysis in G6PD-deficient individuals. If you’re pursuing this as an adjunct therapy for cancer, work with an integrative oncologist experienced with IV protocols.

What About Food Sources?

Red bell peppers deliver about 190 mg of vitamin C per cup. Kiwi, about 70 mg each. Citrus, 50 to 80 mg per piece. Broccoli, 80 mg per cup. Acerola cherries are exceptional at up to 800 mg per 100 grams.

A whole-food plant-based diet rich in raw fruits and vegetables can comfortably deliver 300 to 500 mg of vitamin C per day without any supplementation. That’s quite a bit of vitamin C from food, really.

But here’s the catch. If you’re looking for the effects I mentioned above from the clinical literature at 2,000 to 15,000 mg per day, food alone won’t get you there. You’d have to eat the equivalent of 10 to 80 red bell peppers every day. That’s not a practical dietary strategy. Food establishes your baseline and provides many polyphenols that improve your overall antioxidant status. But to capture the real power of vitamin C, you need to use supplemental forms.

Practical Dosing and Bowel Tolerance

The bowel tolerance method, developed by Dr. Robert Cathcart, is the most practical approach to finding your optimal high-dose intake. Gradually increase your daily dose until you notice loose stools, then back off by 10 to 20 percent. That’s your functional bowel tolerance. It varies significantly among individuals and increases during illness or periods of high oxidative stress.

Healthy adults typically tolerate 4,000 to 15,000 mg per day in divided doses before reaching that threshold. During an acute infection, tolerance can rise dramatically as the body consumes vitamin C faster than it can be cleared.

For sustained high plasma levels, the key is split dosing. Based on the plasma data shown in Figure 1, three to four doses spread throughout the day maintain plasma vitamin C well above 200 micromolar for the entire waking day. Taking 4,000 mg at breakfast, 4,000 mg at midday, and 4,000 mg in the afternoon is a reasonable starting protocol for most people. 

Another way to do it is to take one gram per hour until you reach “bowel tolerance.” Then slow down just a bit. Taking a large loading dose at the beginning of the day is helpful. That will quickly get your vitamin C levels up to a protective level. Then you just add more doses to maintain that high level. This is what you see in Figure 1.

Sodium ascorbate is the most practical form for this approach. Mix one teaspoon of our Vitamin C Powder (Sodium Ascorbate) into water or juice and take three times a day with meals. The neutral pH means you can take 4 to 6 grams per dose without the stomach issues that limit ascorbic acid.

A few cautions. High-dose vitamin C can increase iron absorption, which matters if you have hemochromatosis. People with kidney disease or a history of calcium oxalate kidney stones should consult their physician before taking doses above 1,000 mg per day. G6PD-deficient individuals should avoid IV vitamin C specifically; the oral form is generally safe for them.

A Hallelujah Diet Perspective

Does vitamin C work then? You had questions initially, and after reading all the evidence, you can say, “Yes, it does work.” But you have to use enough. Just like fighting a house fire with a garden hose doesn’t work, you need a fire hose and a pumper truck. Like water for a fire, vitamin C for infections, disease, and toxins is the right tool. You just need enough of it.

Self-healing is built into our bodies by God’s magnificent design. When we supply the body with the building blocks it needs, the ammunition for the immune system, and remove toxins out of the way, it tends to find a healthy way to support the mission we have on Earth. So be encouraged, take hope, don’t listen to industry and media lies, and take your vitamin C. Lots of it. Hallelujah!

Frequently Asked Questions

How much vitamin C is considered a high dose?

Most researchers define high-dose vitamin C as 2,000 mg (2 grams) per day or more. The RDA for adults is 65 to 90 mg per day. Much of the clinical research showing significant effects on specific conditions uses 2,000 to 15,000 mg per day orally, and 15,000 to 100,000 mg per day intravenously for cancer and critical illness applications.

Is it safe to take 5,000 mg of vitamin C a day?

For most healthy adults, 5,000 mg per day in divided doses is within the range that research participants have taken without serious adverse effects. The most common side effect at high oral doses is loose stools, which resolve when you reduce the dose. People with kidney disease, G6PD deficiency, hemochromatosis, or a history of kidney stones should consult their physician before taking doses above 1,000 mg per day.

What is the best form of vitamin C to take?

For most people pursuing high-dose oral supplementation, sodium ascorbate is the most practical choice. It’s metabolically identical to ascorbic acid, but the buffered pH means you can take large doses without stomach irritation. Liposomal vitamin C produces modestly higher plasma levels at low doses, but the advantage diminishes at higher doses, and the cost difference is substantial. Intravenous vitamin C is a different category entirely, appropriate for use as an adjunct therapy in cancer and critical illness under medical supervision.

Does vitamin C help with blood pressure?

Yes, with meaningful but modest effects. Meta-analyses consistently show that vitamin C supplementation reduces systolic blood pressure by 3 to 5 mmHg on average, with larger effects in people who are already hypertensive or diabetic. The mechanism involves vitamin C’s role in maintaining nitric oxide production in endothelial cells. This doesn’t replace medication, but it’s a real tool in a comprehensive cardiovascular strategy.

Can vitamin C help with cancer?

High-dose intravenous vitamin C is being studied as an adjunct to conventional cancer therapy, not as a replacement for it. At IV concentrations, it generates hydrogen peroxide in tumors, selectively damaging cancer cells. Clinical trials have shown it can reduce chemotherapy side effects and improve quality of life. The evidence is strongest for pancreatic cancer. Oral vitamin C cannot reach the plasma concentrations needed for the pro-oxidant anti-tumor mechanism. This is a conversation to have with an integrative oncologist.

References

1. Liu TZ, Chin N, Kiser MD, Bigler WN. Specific spectrophotometry of ascorbic acid in serum or plasma by use of ascorbate oxidase. Clin Chem. 1982;28(11):2225-2228. http://www.clinchem.org/cgi/content/abstract/28/11/2225
2. Padayatty SJ, Sun H, Wang Y, et al. Vitamin C pharmacokinetics: implications for oral and intravenous use. Ann Intern Med. 2004;140(7):533-537. https://doi.org/10.7326/0003-4819-140-7-200404060-00010 [PMID: 15068981]
3. Hemila H. Vitamin C and infections. Nutrients. 2017;9(4):339. https://doi.org/10.3390/nu9040339 [PMID: 28353648]
4. Zhao H, Fu W, Yang X, et al. High-dose vitamin C: a promising anti-tumor agent, insight from mechanisms, clinical research, and challenges. Genes Dis. 2026;13(2):101742. https://doi.org/10.1016/j.gendis.2025.101742 [PMID: 41403402]
5. Alangari A, Arif J, et al. Clinical benefits and risks of high-dose intravenous vitamin C: a systematic review. J Med Life. 2026;19(1):16-23. [PMID: 41815850]
6. Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: Prolongation of survival times in terminal human cancer. Proc Natl Acad Sci USA 1976;73(10):3685–3689. [PMID: 1068480]
7. Marik PE, Khangoora V, Rivera R, Hooper MH, Catravas J. Hydrocortisone, vitamin C, and thiamine for the treatment of severe sepsis and septic shock: a retrospective before-after study. Chest. 2017;151(6):1229-1238. https://doi.org/10.1016/j.chest.2016.11.036 [PMID: 27940189]
8. Fowler AA, Truwit JD, Hite RD, et al. Effect of vitamin C infusion on organ failure and biomarkers of inflammation and vascular injury in patients with sepsis and severe acute respiratory failure. JAMA. 2019;322(13):1261-1270. https://doi.org/10.1001/jama.2019.11825
9. Gokce N, Keaney JF, Frei B, et al. Long-term ascorbic acid administration reverses endothelial vasomotor dysfunction in patients with coronary artery disease. Circulation. 1999;99(25):3234-3240. https://doi.org/10.1161/01.cir.99.25.3234 [PMID: 10385496]
10. Collier BR, Giladi A, Dossett LA, et al. Impact of high-dose antioxidants on outcomes in acutely injured patients. JPEN J Parenter Enteral Nutr. 2008;32(4):384-388. https://doi.org/10.1177/0148607108319808 [PMID: 18596309]
11. Kosari A, Shahinfar H, et al. The effect of vitamin C supplementation on blood pressure in adults: an umbrella review of meta-analyses. Food Funct. 2026;17(6):2643-2654. https://doi.org/10.1039/d5fo03679h [PMID: 41784995]
12. Lbban E, Kwon K, et al. Vitamin C supplementation showed greater effects on systolic blood pressure in hypertensive and diabetic patients. Int J Food Sci Nutr. 2023;74(8):814-825. https://doi.org/10.1080/09637486.2023.2264549 [PMID: 37791386]
13. Nosratabadi S, Ashtary-Larky D, et al. The effects of vitamin C supplementation on glycemic control in patients with type 2 diabetes: a systematic review and meta-analysis. Diabetes Metab Syndr. 2023;17(8):102824. https://doi.org/10.1016/j.dsx.2023.102824 [PMID: 37523928]
14. Eriksson J, Kohvakka A. Magnesium and ascorbic acid supplementation in diabetes mellitus. Ann Nutr Metab. 1995;39(4):217-223. https://doi.org/10.1159/000177865
15. Frei, B., England, L., & Ames, B. N. (1989). Ascorbate is an outstanding antioxidant in human blood plasma. Proc Natl Acad Sci USA. 1989:86(16), 6377–6381. https://doi.org/10.1073/pnas.86.16.6377
16. Chou CC, Sung YC, Davison G, Chen CY, Liao YH. Short-Term High-Dose Vitamin C and E Supplementation Attenuates Muscle Damage and Inflammatory Responses to Repeated Taekwondo Competitions: A Randomized Placebo-Controlled Trial. Int J Med Sci. 2018;15(11):1217-1226. https://doi.org/10.7150/ijms.26340
17. Levy TE. Vitamin C: Infectious Diseases and Toxins. Xlibris Corporation; 2002.
18. Davis JL, Paris HL, Beals JW, et al. Liposomal-encapsulated Ascorbic Acid: Influence on Vitamin C Bioavailability and Capacity to Protect Against Ischemia–Reperfusion Injury. Nutr Metab Insights. 2016;9:25-30. doi:10.4137/NMI.S39764