The health effects of vitamin C supplementation: a review.

Bendich, Adrianne; Langseth, L

doi:10.1080/07315724.1995.10718484

Cited by 126 publications

(59 citation statements)

References 119 publications

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“…The importance of vitamin C in protecting against exercise-induced oxidative stress is not well-established, partly because most mammalian species synthesize vitamin C, making a deficiency study rather difficult. Vitamin C also performs numerous functions that are not related to those of antioxidants (67). By reducing dietary vitamin C content to 10% of the normal values (0.2 g/kg), Packer et al (68) demonstrated that myocardial capacity to oxidize pyruvate, 2-oxoglutarate and succinate was significantly reduced in guinea pigs (which can not synthesize vitamin C) vs. controls.…”

Section: Non-enzymatic Antioxidantsmentioning

confidence: 99%

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

Leichtweis

1997

AGE

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Strenuous exercise is characterized by increased oxygen consumption and the disturbance between intracellular pro-oxidant and antioxidant homeostasis. At lease three biochemical pathways (i.e., mitochondrial electron transport chain, xanthine oxidase, and polymorphoneutrophil) have been identified as potential sources of intracellular free radical generation during exercise. These deleterious reactive oxygen species pose a serious threat to the cellular antioxidant defense system, such as diminished reserves of antioxidant vitamins and glutathione. However, enzymatic and non-enzymatic antioxidants have demonstrated great versitility and adaptability in response to acute and chronic exercise. The delicate balance between pro-oxidants and antioxidants suggests that supplementation with antioxidants may be desirable for physically active individuals under certain physiological conditions by providing a larger protective margin.

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Section: Non-enzymatic Antioxidantsmentioning

confidence: 99%

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

Leichtweis

1997

AGE

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“…The current recommended dietary allowance (1) for vitamin C is 60 mg/day for nonsmoking adult males, which is sufficient to prevent scurvy (5). However, vitamin C has been suggested as having both a preventative and therapeutic role in a number of other pathologies when administered at much higher-than-recommended dietary allowance levels, including cancer (6), atherosclerosis (7), and viral infections (8,9).…”

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confidence: 99%

Vitamin C Inhibits NF-κB Activation by TNF Via the Activation of p38 Mitogen-Activated Protein Kinase

Bowie

O’Neill

2000

The Journal of Immunology

295

173

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The transcription factor NF-κB is a central mediator of altered gene expression during inflammation, and is implicated in a number of pathologies, including cancer, atherosclerosis, and viral infection. We report in this study that vitamin C inhibits the activation of NF-κB by multiple stimuli, including IL-1 and TNF in the endothelial cell line ECV304 and in primary HUVECs. The induction of a NF-κB-dependent gene, IL-8, by TNF was also inhibited. The effect requires millimolar concentrations of vitamin C, which occur intracellularly in vivo, particularly during inflammation. Vitamin C was not toxic to cells, did not inhibit another inducible transcription factor, STAT1, and had no effect on the DNA binding of NF-κB. Inhibition by vitamin C was not simply an antioxidant effect, because redox-insensitive pathways to NF-κB were also blocked. Vitamin C was shown to block IL-1- and TNF-mediated degradation and phosphorylation of I-κBα (inhibitory protein that dissociates from NF-κB), due to inhibition of I-κB kinase (IKK) activation. Inhibition of TNF-driven IKK activation was mediated by p38 mitogen-activated protein kinase, because treatment of cells with vitamin C led to a rapid and sustained activation of p38, and the specific p38 inhibitor SB203580 reversed the inhibitory effect of vitamin C on IKK activity, I-κBα phosphorylation, and NF-κB activation. The results identify p38 as an intracellular target for high dose vitamin C.

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“…Anderson had reported a 30% decrease (P < 0.001) in the total number of days confined to house per subject (5). Many people might consider that with an inexpensive nutrient that costs pennies per gram and that is safe in large doses (41,52,53) even such moderate benefits are worthy of exploitation irrespective of how they compare to Pauling's predictions.…”

Section: Conceptual Problems In the Interpretation Of Common Cold Stumentioning

confidence: 99%

“…It also seems important to understand the biochemical mechanisms of the effect as this could eventually help in the identification of groups of people who would benefit most. Furthermore, it may be asked whether vitamin C supplementation has moderate effects on certain other diseases, as has been suggested in a few recent reviews (41,53,(58)(59)(60)(61)(62)(63).…”

Section: Open Questionsmentioning

confidence: 99%

Vitamin C supplementation and common cold symptoms: Problems with inaccurate reviews

Hemilä

1996

Nutrition

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In 1971, Linus Pauling carried out a meta-analysis of four placebo-controlled trials and concluded that it was highly unlikely that the decrease in the "integrated morbidity of the common cold" in vitamin C groups was caused by chance alone (P < 0.00003). Studies carried out since then have consistently found that vitamin C ( 1 g/d) alleviates common cold symptoms, indicating that the vitamin does indeed have physiologic effects on colds. However, widespread conviction that the vitamin has no proven effects on the common cold still remains. Three of the most influential reviews drawing this conclusion are considered in the present article. Two of them are cited in the current edition of the RDA nutritional recommendations as evidence that vitamin C is ineffective against colds. In this article, these three reviews are shown to contain serious inaccuracies and shortcomings, making them unreliable sources on the topic. The second purpose is to suggest possible conceptual reasons for the persistent resistance to the notion that vitamin C might have effects on colds. Although placebo-controlled trials have shown that vitamin C does alleviate common cold symptoms, important questions still remain.

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The health effects of vitamin C supplementation: a review.

Cited by 126 publications

References 119 publications

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

Vitamin C Inhibits NF-κB Activation by TNF Via the Activation of p38 Mitogen-Activated Protein Kinase

Vitamin C supplementation and common cold symptoms: Problems with inaccurate reviews

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