Effects of High Doses of Vitamin C on Cancer Patients in Singapore

Raymond, Yuen Chuen Fong; Glenda, Chong Sze Ling; Meng, Lim Kah

doi:10.1177/1534735415622010

Cited by 29 publications

(23 citation statements)

References 22 publications

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“…Instead they found that supplementary vitamin D was strongly associated with lessened disability for knee OA patients (28). Some studies report in oncology that the use of Vitamin C improves the quality of life of the oncological patient (29, 30). However, the reduction in quality of life is led to the reduction of pain.…”

Section: Discussionmentioning

confidence: 99%

Vitamin C May Help to Reduce the Knee's Arthritic Symptoms. Outcomes Assessment of Nutriceutical Therapy

et al. 2019

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Introduction: Osteoarthritis (OA) is a chronic joint disease characterized by degeneration of the articular cartilage, changes in the physico-chemical properties of the synovial fluid and macroscopical modifications of the joint. Patients with Classes I and II of Knee OA can be treated with pharmacologic therapy. Vitamin C is key for both preventing inflammatory arthritis and maintaining healthy joints with OA. Aim: The aim of our paper is to verify the effectiveness of the addition of vitamin c in nutriceutical drugs for the therapy of the knee arthritis in the young adult. Results: Group B has a lower VAS score at 6 and 12 months with p<0.05. Not statistical difference we found in KSS during all follow up. A better quality of life was founded in Group B at 12 months in group B(p<0.05) and less use of pain killers/monthly(p<0.05). Conclusion: There is no denying that vitamin C benefits everybody, whether they have arthritis or not. Therefore, it is a good idea to maintain a healthy balance of vitamin C. Without a doubt, vitamin C benefits most people with early OA.

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Section: Discussionmentioning

confidence: 99%

Vitamin C May Help to Reduce the Knee's Arthritic Symptoms. Outcomes Assessment of Nutriceutical Therapy

et al. 2019

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“…There is an acknowledged need for good clinical studies to determine the anticancer efficacy of this practice and to establish appropriate clinical guidelines. Case reports suggest that there may be circumstances under which vitamin C can provide a clinical benefit (these are usually high intravenous doses, given as a course over months) ( Drisko et al, 2003 ; Padayatty et al, 2006 ; Mikirova et al, 2016 ; Raymond et al, 2016 ) and recent phase I trials have indicated that high-dose vitamin C is a useful adjunct to chemotherapy ( Welsh et al, 2013 ; Hoffer et al, 2015 ). However, given the prevalence of ascorbate use by cancer patients, clinical advantage is not commonly seen, suggesting that only a subset of patients may benefit.…”

Section: Introductionmentioning

confidence: 99%

Potential Mechanisms of Action for Vitamin C in Cancer: Reviewing the Evidence

2018

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Whether vitamin C (ascorbate) has a role to play as an anti-cancer agent has been debated for decades. Ascorbate has been used by cancer patients in an unregulated environment, either as a dietary supplement or in pharmacological doses administered by infusion, with numerous reports of clinical benefit, but in the absence of rigorous clinical trial data. The design of appropriate clinical trials has been hindered by a lack of understanding of the mechanism(s) of action that would inform the choice of effective dose, timing of administration and likely responsive cancer models. More recently, expanded understanding of the biological activities of ascorbate has led to a number of plausible hypotheses for mechanisms of anti-cancer activity. Prominent among these are the generation of significant quantities of hydrogen peroxide by the autoxidation of supra-physiological concentrations of ascorbate and stimulation of the 2-oxoglutarate-dependent dioxygenase family of enzymes (2-OGDDs) that have a cofactor requirement for ascorbate. Hydrogen peroxide generation is postulated to generate oxidative stress that preferentially targets cancer cells. The 2-OGDDs include the hydroxylases that regulate the hypoxic response, a major driver of tumor survival, angiogenesis, stem cell phenotype and metastasis, and the epigenetic histone and DNA demethylases. The latter are of particular interest, with recent studies suggesting a promising role for ascorbate in the regulation of the ten-eleven translocase (TET) DNA demethylases in hematological cancers. Support for these proposed mechanisms has come from many in vitro studies, and xenograft animal models have consistently shown an anti-cancer effect of ascorbate administration. However, decisive evidence for any particular mechanism(s) of action is not yet available from an in vivo setting. With a number of early phase clinical trials currently underway, evidence for potential mechanism(s) of action is required to inform the most appropriate study design and choice of cancer model. Hopefully such information will result in sound clinical data that will avert adding any further controversy to this already contentious debate.

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“…Pharmacokinetic studies in humans have shown that intravenous administration of sodium L-ascorbate can generate up to 30 mM peak plasma levels, 100-fold higher than the levels produced by high-dose oral administration, and is not toxic due to the rapid elimination (a few hours [19,58]). Recent clinical trials and case studies have shown efficacy of vitamin C as an anticancer agent when administered IV at high doses ranging from 0.4 to 1.5 g ascorbate/kg body weight to treat patients with a variety of solid tumors including breast, ovarian, prostate, kidney, lung, and liver cancer [72,[97][98][99][100][101][102]. Recently, high-dose vitamin C was shown to be selectively toxic to KRAS or BRAF mutant colorectal cancer cells [93].…”

Section: Medical Significance Of the Modelmentioning

confidence: 99%

On the physiological and cellular homeostasis of ascorbate

Przybyło

Langner

2020

Cell Mol Biol Lett

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Recent interest in the role of ascorbate in crucial metabolic processes is driven by the growing number of medical reports that show beneficial effects of ascorbate supplementation for maintaining general well-being and recovery from a variety of medical conditions. The effect of ascorbate on the local body environment highly depends on its local concentration; at low concentrations it can cause the reduction of reactive oxygen and facilitate activities of enzymes, while at high concentrations it generates free radicals by reducing ferric ions. Ascorbate serving as an electron donor assists the iron-containing proteins and the iron transfer between various aqueous compartments. These functions require effective and adjustable mechanisms responsible for ascorbate biodistribution. In the paper we propose a new biophysical model of ascorbate redistribution between various aqueous body compartments. It combines recent experimental evidence regarding the ability of ascorbate to cross the lipid bilayer by unassisted diffusion, with active transport by well-characterized sodium vitamin C transporter (SVCT) membrane proteins. In the model, the intracellular concentration of ascorbate is maintained by the balance of two opposing fluxes: fast active and slow passive transport. The model provides a mechanistic understanding of ascorbate flux across the epidermal barrier in the gut as well as the role of astrocytes in ascorbate recycling in the brain. In addition, ascorbate passive diffusion across biological membranes, which depends on membrane electric potentials and pH gradients, provides the rationale for the correlation between ascorbate distribution and the transfer of iron ions inside a cell. The proposed approach provides, for the first time, a mechanistic account of processes leading to ascorbate physiological and cellular distribution, which helps to explain numerous experimental and clinical observations.

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Effects of High Doses of Vitamin C on Cancer Patients in Singapore

Cited by 29 publications

References 22 publications

Vitamin C May Help to Reduce the Knee's Arthritic Symptoms. Outcomes Assessment of Nutriceutical Therapy

Vitamin C May Help to Reduce the Knee's Arthritic Symptoms. Outcomes Assessment of Nutriceutical Therapy

Potential Mechanisms of Action for Vitamin C in Cancer: Reviewing the Evidence

On the physiological and cellular homeostasis of ascorbate

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