scholarly journals Unintended Consequence of High-Dose Vitamin C Therapy for an Oncology Patient: Evaluation of Ascorbic Acid Interference With Three Hospital-Use Glucose Meters

2020 ◽  
pp. 193229682093218
Author(s):  
Brooke M. Katzman ◽  
Brandon R. Kelley ◽  
Gayle R. Deobald ◽  
Nikki K. Myhre ◽  
Sean A. Agger ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
High Dose ◽  
Oncology Patient ◽  
Glucose Meter ◽  
High Doses ◽  
The Impact ◽  
Very High ◽  
High Dose Vitamin ◽  
Hospital Use

The use of high-dose vitamin C in cancer care has offered promising results for some patients. However, the intravenous (IV) doses used for these patients can reach concentrations that interfere with some strip-based glucose meters. We characterized the impact of vitamin C interference, from standard to the very high doses used for some cancer protocols, using three different hospital-use glucose meters. For two of the three devices tested, increasing concentrations of ascorbic acid caused false elevations in the glucose measurements. The third glucose meter did not provide inaccurate results, regardless of the vitamin C concentration present. Rather, above a certain threshold, the device generated error messages and no results could be obtained.

scholarly journals High-dose vitamin C enhances cancer immunotherapy

2020 ◽  
Vol 12 (532) ◽  
pp. eaay8707 ◽  
Author(s):  
Alessandro Magrì ◽  
Giovanni Germano ◽  
Annalisa Lorenzato ◽  
Simona Lamba ◽  
Rosaria Chilà ◽  
...  
Keyword(s):  
Immune System ◽  
Vitamin C ◽  
Clinical Evidence ◽  
High Dose ◽  
Dependent Manner ◽  
Cancer Cell Growth ◽  
Mutational Burden ◽  
Cancer Types ◽  
High Doses ◽  
High Dose Vitamin

Vitamin C (VitC) is known to directly impair cancer cell growth in preclinical models, but there is little clinical evidence on its antitumoral efficacy. In addition, whether and how VitC modulates anticancer immune responses is mostly unknown. Here, we show that a fully competent immune system is required to maximize the antiproliferative effect of VitC in breast, colorectal, melanoma, and pancreatic murine tumors. High-dose VitC modulates infiltration of the tumor microenvironment by cells of the immune system and delays cancer growth in a T cell–dependent manner. VitC not only enhances the cytotoxic activity of adoptively transferred CD8 T cells but also cooperates with immune checkpoint therapy (ICT) in several cancer types. Combination of VitC and ICT can be curative in models of mismatch repair–deficient tumors with high mutational burden. This work provides a rationale for clinical trials combining ICT with high doses of VitC.

scholarly journals Vitamin C and Sepsis

2021 ◽  
Author(s):  
Adriana Françozo de Melo ◽  
Giulia Oliveira Timo ◽  
Mauricio Homem-de-Mello
Keyword(s):  
Reactive Oxygen Species ◽  
Immune Response ◽  
Ascorbic Acid ◽  
Vitamin C ◽  
High Dose ◽  
Supportive Treatment ◽  
Tnf Α ◽  
The Moment ◽  
Cellular Immune ◽  
Very High

Vitamin C is a supplement used orally by several people globally. It may help in many other conditions, like sepsis, which is caused by an infection that leads to an imbalanced immune response involving pro (e.g., TNF-α, IL-1, IL-2, IL-6) and anti-inflammatory (e.g., IL-10, IL-4, IL-7) cytokines. Ascorbic acid is an antioxidant and acts against reactive oxygen species. At the same time, this vitamin influences cellular immune signaling, avoiding exacerbated transcription of pro-inflammatory cytokines. Very high intravenous doses have already shown to be beneficial in septic patients. Some clinical trials are still running to evaluate the real impact of vitamin C in this condition. To the moment, the combination of low-dose corticosteroids, high-dose parenteral ascorbate, and thiamine seems to be the most effective supportive treatment that could help septic patients recover.

scholarly journals Decreased expression of the vitamin C transporter SVCT1 by ascorbic acid in a human intestinal epithelial cell line

2002 ◽  
Vol 87 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Lauren MacDonald ◽  
Alfred E. Thumser ◽  
Paul Sharp
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Cell Model ◽  
Human Kidney ◽  
The Body ◽  
Epithelial Cell Line ◽  
High Dose ◽  
Acid Uptake ◽  
Cellular Processes ◽  
High Doses

Vitamin C (ascorbic acid) is an essential nutrient that is involved in a number of cellular processes. However, unlike most mammals, man is unable to synthesize vitamin C and it must therefore be acquired from the diet. Absorption of vitamin C is achieved by two transporters, SVCT1 and SVCT2, recently cloned from rat and human kidney. SVCT1 is thought to be the predominant transporter in the intestine. Vitamin C supplements are increasingly common, thus contributing to an increased dietary load, and therefore the aim of the present study was to investigate the effect of high doses of ascorbic acid on SVCT1 expression. Using the Caco-2 TC7 cell model of small intestinal enterocytes, we measured the effects of ascorbic acid (4·5 mg/ml culture medium) on L-[14C]ascorbic acid uptake and SVCT1 expression (determined by reverse transcription-polymerase chain reaction). Ascorbic acid uptake was decreased significantly in Caco-2 TC7 cells exposed to ascorbate for 24 h (-50 %, P<0·0005). Expression of SVCT1 was also significantly reduced by exposure to elevated levels of ascorbate for 24 h (-77 %, P<0·005). Taken together these results suggest that high-dose supplements might not be the most efficient way of increasing the body pool of vitamin C.

scholarly journals Report of the Pilot Study Done for the Proposed Investigation on the Possible Synergic Effect between High-Dose Ascorbic Acid Application and Oncothermia Treatment

2013 ◽  
Vol 2013 ◽  
pp. 1-2
Author(s):  
Csaba Kovago ◽  
Nora Meggyeshazi ◽  
Gabor Andocs ◽  
Andras Szasz
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Internal Control ◽  
Remission Rate ◽  
Treatment Method ◽  
High Dose ◽  
Main Question ◽  
High Doses ◽  
The Right

According to recent investigations, the parenteral application of ascorbic acid (vitamin C) at high doses has significant antitumor activity in in vitro assays. The goal of our experiment was to determine the possible potentiating effect of application of high dose pH-neutralized ascorbic acid to the normal oncothermia treatment method. The NMRI mice were inoculated with C26 murine colon carcinoma cell line subcutaneously at both of their femoral regions and were kept till the tumors reached symmetrically 10 mm in diameter. We created four experimental groups, containing 5 male and 5 female animals in each. Both vitamin-C and oncothermia treatments were applied once; ascorbic acid was applied intra-peritoneally. Oncothermia treatment was applied only to the right limb tumor; the other side will be used as internal control. After the treatment, the animals were sacrificed, and all tumors were removed and analyzed histopathologically. Our main question centers on the comparison of the cell destruction ratio of the various applied treatment regimes, and studies the possible synergy or additive cross-potentiating of the methods. The results of this experiment turned out to be controversial, since the ascorbic acid did not change the remission rate of the allografts and showed no synergy with oncothermia.

Failure of High-Dose Vitamin C (Ascorbic Acid) Therapy to Benefit Patients with Advanced Cancer

1979 ◽  
Vol 301 (13) ◽  
pp. 687-690 ◽  
Author(s):  
Edward T. Creagan ◽  
Charles G. Moertel ◽  
Judith R. O'Fallon ◽  
Allan J. Schutt ◽  
Michael J. O'Connell ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Advanced Cancer ◽  
High Dose ◽  
Acid Therapy ◽  
High Dose Vitamin

High-dose Vitamin C: A Risk for Persons with High Iron Stores?

1999 ◽  
Vol 69 (2) ◽  
pp. 67-82 ◽  
Author(s):  
Gerster
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Iron Overload ◽  
Deficiency Anemia ◽  
High Dose ◽  
Iron Stores ◽  
High Iron ◽  
Increased Risk ◽  
And Storage ◽  
High Dose Vitamin

The contribution of vitamin C (ascorbic acid) to the prevention of iron deficiency anemia by promoting the absorption of dietary non-heme iron – especially in persons with low iron stores – is well established. But the question has been raised whether high-dose intakes of vitamin C might unduly enhance the absorption of dietary iron in persons with high iron stores or in patients with iron overload, possibly increasing the potential risk of iron toxicity. Extensive studies have shown that overall the uptake and storage of iron in humans is efficiently controlled by a network of regulatory mechanisms. Even high vitamin C intakes do not cause iron imbalance in healthy persons and probably in persons who are heterozygous for hemochromatosis. The uptake, renal tubular reabsorption and storage of vitamin C itself are also strictly limited after high-dose intake so that no excessive plasma and tissue concentrations of vitamin C are produced. The effect of high-dose vitamin C on iron absorption in patients with iron overload due to homozygous hemochromatosis has not been studied. Of special importance is the early identification of hemochromatosis patients, which is assisted by the newly developed PCR test for hereditary hemochromatosis. Specific treatment consists of regular phlebotomy and possibly iron-chelating therapy. These patients should moreover avoid any possibility of facilitated absorption of iron and need to limit their intake of iron. Patients with beta-thalassemia major and sickle cell anemia who suffer from iron overload due to regular blood transfusions or excessive destruction of red blood cells need specialized medical treatment with iron chelators and should also control their intake of iron. The serum of patients with pathological iron overload can contain non-transferrin-bound iron inducinglipid peroxidation with subsequent consumption of antioxidants such as vitamin E and vitamin C. The role of iron in coronary heart disease and cancer is controversial. Early suggestions that moderately elevated iron stores are associated with an increased risk of CHD have not been confirmed by later studies. In vitro, ascorbic acid can act as a prooxidant in the presence of transition metals such as iron or copper, but in the living organism its major functions are as an antioxidant. High intakes of vitamin C have thus not been found to increase oxidative damage in humans. Accordingly, the risk of CHD or cancer is not elevated. On the contrary, most studies have shown that diets rich in vitamin C are inversely related to the incidence of these diseases.

The efficacy of high doses of vitamin C in patients with paraquat poisoning

2010 ◽  
Vol 30 (8) ◽  
pp. 844-850 ◽  
Author(s):  
Jeong Mi Moon ◽  
Byeong Jo Chun
Keyword(s):  
Vitamin C ◽  
Multivariate Logistic Regression Analysis ◽  
Kidney Injury ◽  
Pulse Therapy ◽  
High Dose ◽  
Difficult Condition ◽  
Group 2 ◽  
High Doses ◽  
High Dose Vitamin ◽  
Group 1

Paraquat (PQ) poisoning is an extremely difficult condition to manage clinically because of the lack of effective treatments. The purpose of this study was to assess the effect of high doses of vitamin C in combination with anti-inflammatory and immunosuppressant therapy in patients with PQ poisoning. The medical records of 134 patients who presented to the emergency department within 24 hours after PQ poisoning were reviewed retrospectively. The 57 patients presented between January 2004 and September 2005 were group 1; they received pulse therapy, which included cyclophosphamide and methylprednisolone, followed by the administration of dexamethasone over 2 weeks. The 77 patients that presented between October 2005 and January 2008 were group 2; they received the above-mentioned therapy and high-dose vitamin C for 2 weeks. There was no difference in the distribution of baseline variables between the 2 groups. However, group 2 showed a significant reduction in acute kidney injury related to PQ. Furthermore, a multivariate logistic regression analysis showed that the addition of vitamin C to the treatment was significantly associated with an increased survival of the patients. Larger trials will be needed to verify the effect of high-dose vitamin C on survival in patients with PQ poisoning.

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