Vitamin C

[yerrag]

Yeah for sure, cancer can be brewing below the surface for a decade before revealing itself. Another reason to keep C high! I'd rather deal with possible higher requirements for certain minerals than die of terrible diseases.

Yes. It's nice when you think about it. The Vitamin -C Flush test is a cheap reality check on our health status.

 

[Amazoniac]

Pharmacokinetics of vitamin C: insights into the oral and intravenous administration of ascorbate

"[..]repeated oral doses [] may result in sustained plasma ascorbate levels. Keep in mind that the larger the oral vitamin C dose, the more incompletely absorbed from the gut."

"Vitamin C in doses up to 50 grams per day, infused slowly, was not toxic to cancer patients and, even more importantly, some patients had complete remission after high doses following intravenous infusion. Although concentrations that kill most tumor cells (i.e., 200 - 400 mg/dl) were not achieved after infusion of 30 grams of vitamin C, remissions were still observed in patients treated with this dose level, which was assumed by the authors to occur as a result of vitamin C induced biological response modification rather than its cytotoxic potential (40). It could also result from the subject simply having a high level of copper or iron that enhances hydrogen peroxide production by ascorbate in a Fenton-like reaction. The cytotoxic action of vitamin C is greatly enhanced by the presence of synergistic substances such as vitamin K3 or other quinones, lipoic acid, oxygen and futile redox cycling substances."

"Blanchard et al. presented their “ceiling effect” hypothesis for ascorbate pharmacokinetics after megadoses (45). They argued that as the daily oral dose is increased, the background concentration of ascorbate in the plasma and other body compartments does not increase proportionally, but instead tends to approach an upper limit. For example, when the daily dose is increased from 200 to 2,500 mg (1.1 to 14.2 mmol) the peak plasma response increases, but the background concentration increases only from 12 to 15 mg/L (68.1 to 85.2 μM)." "[..]these authors only focus their analysis on pharmacokinetic data from young, healthy male volunteers instead of cancer patients. That is, the implications of the disease-state condition on ascorbate pharmacokinetics must be considered as a factor at the moment of analyzing the pharmacokinetic perspective of [intravenous] megadose use."

"Hickey, Roberts and Cathcart’s paper suggested that the NIH’s misinterpretation of oral ascorbate bioavailability has an impact on the proposed RDA for vitamin C (28). According to the NIH viewpoint, the ascorbate bioavailability is maximized at a dose of 200 mg. This statement assumed a complete absorption of ascorbate by the body at this dose, or at lower intakes whereas a smaller proportion (although a higher absolute amount) will be absorbed after higher doses.
Notably, as Hickey and co-workers pointed out, the short half-life of vitamin C during the rapid excretion phase is sometimes ignored (28). Plasma levels above 70 μM have a half-life of approximately 30 minutes, so large doses taken several hours apart should be considered independent, as should be their bioavailability. This cumulative pattern means that splitting a single large dose into several smaller ones, taken a few hours apart, increases the effective bioavailability of the large dose. This schedule dependence phenomenon needs to be taken into consideration for any further interpretation of ascorbate pharmacokinetic and pharmacodynamic results."

"Cathcart’s bowel tolerance method indicates that individual bioavailability can vary by a factor of at least two orders of magnitude, thus confirming that any variation depends upon the individual’s health status (47). Accordingly, bioavailability is not a static property of ascorbate, but is subject to individual differences and varies with the timing of the dose. It follows that the appropriate intake will vary widely, both between individuals and also over time for the same person, depending on factors such as state of health and intake patterns, among others."

"Blanchard and co-workers published various ascorbate bioavailability values [↓, or ↯ if you're Zeus] calculated from different literature reports (45). The estimated dose-dependent absorbed fractions (bioavailability) using either the mean plasma ascorbate concentrations or the urinary recovery data were observed at daily vitamin C doses ranging from 200 mg (1.1 mmol) to 2,500 mg (14.2 mmol) and from 1 (5.7 mmol) to 12 g (68.1 mmol), in several reference sources.
The tendency for bioavailability to decrease with increasing dose is clearly evident from the literature values cited. However, the magnitudes of the bioavailability values reported in the literature for daily doses higher than 200 mg were considerably greater than the values calculated by Blanchard and co-workers (45). One reason for this discrepancy was proposed by the authors who argued that bioavailability is commonly calculated from the ratio of oral to intravenous AUC, assuming that the AUC is directly proportional to the amount absorbed, which implies constancy of clearance. But plasma ascorbate concentrations are often considerably higher soon after an intravenous dose than after oral administration and consequently the excretion rate of ascorbate would be greater after intravenous dosing than after an equivalent oral input. Because of the nonlinear renal tubular reabsorption, a direct comparison of an oral AUC with an intravenous AUC will produce an overestimation of oral bioavailability.
In addition, the oral bioavailability estimates reported in the literature may be somewhat biased because they are frequently based on the assumption that the rate of ascorbate absorption is linear and therefore the nonlinear carrier-mediated absorption is often ignored. Likewise, multiple oral doses are expected to produce fluctuations in the absorption rate. Despite the uncertainty in the estimation of oral bioavailability, the analysis suggests that plasma ascorbate concentrations largely depend on limited absorption, probably as a result of a saturable transport mechanism."

"[Due to saturable absorption,] the bioavailability of ascorbate will be increased when given in divided doses or concurrently with food (48)."

"[..]the depletion of tissue ascorbate in cancer and other chronic diseases is associated with an excessive catabolism of proteins (11, 50)."

"Ascorbate can generate hydrogen peroxide upon oxidation in biological systems. This action can be enhanced by divalent cations such as iron and copper. Hydrogen peroxide may further generate additional reactive species and secondary products of oxidation. In general, the cytotoxicity induced by ascorbate seems to be primarily mediated by hydrogen peroxide formation."

"Reviewing the current literature, most studies have used single large daily, or twice-a-day, doses of vitamin C. Occasional studies have used low-dose, slow release formulations. A large single daily dose will produce only a transient increase in plasma levels. Such once or twice daily mega-dose supplementation of ascorbate will not load tissues, such as red blood cells, or increase the body pool substantially; and therefore, would not be expected to show more than a minimal biological effect, when compared with the dynamic flow model."​

[45] Pharmacokinetic perspectives on megadoses of ascorbic acid

For a laxative effect: single bolus dose.
For sustaining high vitamin C levels: spread dose throughout the day, it might be possible to achieve better results using much less in total.

 

[Braveheart]

Pharmacokinetics of vitamin C: insights into the oral and intravenous administration of ascorbate

"[..]repeated oral doses [] may result in sustained plasma ascorbate levels. Keep in mind that the larger the oral vitamin C dose, the more incompletely absorbed from the gut."

"Vitamin C in doses up to 50 grams per day, infused slowly, was not toxic to cancer patients and, even more importantly, some patients had complete remission after high doses following intravenous infusion. Although concentrations that kill most tumor cells (i.e., 200 - 400 mg/dl) were not achieved after infusion of 30 grams of vitamin C, remissions were still observed in patients treated with this dose level, which was assumed by the authors to occur as a result of vitamin C induced biological response modification rather than its cytotoxic potential (40). It could also result from the subject simply having a high level of copper or iron that enhances hydrogen peroxide production by ascorbate in a Fenton-like reaction. The cytotoxic action of vitamin C is greatly enhanced by the presence of synergistic substances such as vitamin K3 or other quinones, lipoic acid, oxygen and futile redox cycling substances."

"Blanchard et al. presented their “ceiling effect” hypothesis for ascorbate pharmacokinetics after megadoses (45). They argued that as the daily oral dose is increased, the background concentration of ascorbate in the plasma and other body compartments does not increase proportionally, but instead tends to approach an upper limit. For example, when the daily dose is increased from 200 to 2,500 mg (1.1 to 14.2 mmol) the peak plasma response increases, but the background concentration increases only from 12 to 15 mg/L (68.1 to 85.2 μM)." "[..]these authors only focus their analysis on pharmacokinetic data from young, healthy male volunteers instead of cancer patients. That is, the implications of the disease-state condition on ascorbate pharmacokinetics must be considered as a factor at the moment of analyzing the pharmacokinetic perspective of [intravenous] megadose use."

"Hickey, Roberts and Cathcart’s paper suggested that the NIH’s misinterpretation of oral ascorbate bioavailability has an impact on the proposed RDA for vitamin C (28). According to the NIH viewpoint, the ascorbate bioavailability is maximized at a dose of 200 mg. This statement assumed a complete absorption of ascorbate by the body at this dose, or at lower intakes whereas a smaller proportion (although a higher absolute amount) will be absorbed after higher doses.
Notably, as Hickey and co-workers pointed out, the short half-life of vitamin C during the rapid excretion phase is sometimes ignored (28). Plasma levels above 70 μM have a half-life of approximately 30 minutes, so large doses taken several hours apart should be considered independent, as should be their bioavailability. This cumulative pattern means that splitting a single large dose into several smaller ones, taken a few hours apart, increases the effective bioavailability of the large dose. This schedule dependence phenomenon needs to be taken into consideration for any further interpretation of ascorbate pharmacokinetic and pharmacodynamic results."

"Cathcart’s bowel tolerance method indicates that individual bioavailability can vary by a factor of at least two orders of magnitude, thus confirming that any variation depends upon the individual’s health status (47). Accordingly, bioavailability is not a static property of ascorbate, but is subject to individual differences and varies with the timing of the dose. It follows that the appropriate intake will vary widely, both between individuals and also over time for the same person, depending on factors such as state of health and intake patterns, among others."

"Blanchard and co-workers published various ascorbate bioavailability values [↓, or ↯ if you're Zeus] calculated from different literature reports (45). The estimated dose-dependent absorbed fractions (bioavailability) using either the mean plasma ascorbate concentrations or the urinary recovery data were observed at daily vitamin C doses ranging from 200 mg (1.1 mmol) to 2,500 mg (14.2 mmol) and from 1 (5.7 mmol) to 12 g (68.1 mmol), in several reference sources.
The tendency for bioavailability to decrease with increasing dose is clearly evident from the literature values cited. However, the magnitudes of the bioavailability values reported in the literature for daily doses higher than 200 mg were considerably greater than the values calculated by Blanchard and co-workers (45). One reason for this discrepancy was proposed by the authors who argued that bioavailability is commonly calculated from the ratio of oral to intravenous AUC, assuming that the AUC is directly proportional to the amount absorbed, which implies constancy of clearance. But plasma ascorbate concentrations are often considerably higher soon after an intravenous dose than after oral administration and consequently the excretion rate of ascorbate would be greater after intravenous dosing than after an equivalent oral input. Because of the nonlinear renal tubular reabsorption, a direct comparison of an oral AUC with an intravenous AUC will produce an overestimation of oral bioavailability.
In addition, the oral bioavailability estimates reported in the literature may be somewhat biased because they are frequently based on the assumption that the rate of ascorbate absorption is linear and therefore the nonlinear carrier-mediated absorption is often ignored. Likewise, multiple oral doses are expected to produce fluctuations in the absorption rate. Despite the uncertainty in the estimation of oral bioavailability, the analysis suggests that plasma ascorbate concentrations largely depend on limited absorption, probably as a result of a saturable transport mechanism."

"[Due to saturable absorption,] the bioavailability of ascorbate will be increased when given in divided doses or concurrently with food (48)."

"[..]the depletion of tissue ascorbate in cancer and other chronic diseases is associated with an excessive catabolism of proteins (11, 50)."

"Ascorbate can generate hydrogen peroxide upon oxidation in biological systems. This action can be enhanced by divalent cations such as iron and copper. Hydrogen peroxide may further generate additional reactive species and secondary products of oxidation. In general, the cytotoxicity induced by ascorbate seems to be primarily mediated by hydrogen peroxide formation."

"Reviewing the current literature, most studies have used single large daily, or twice-a-day, doses of vitamin C. Occasional studies have used low-dose, slow release formulations. A large single daily dose will produce only a transient increase in plasma levels. Such once or twice daily mega-dose supplementation of ascorbate will not load tissues, such as red blood cells, or increase the body pool substantially; and therefore, would not be expected to show more than a minimal biological effect, when compared with the dynamic flow model."​

[45] Pharmacokinetic perspectives on megadoses of ascorbic acid

View attachment 9359​

For a laxative effect: single bolus dose.
For sustaining high vitamin C levels: spread dose throughout the day, it might be possible to achieve better results using much less in total.

Excellent and timely, as I have been considering the Pauling Therapy...but have had my doubts about amt and timing after much reading...I have also come to the conclusion that smaller doses multiple times might be more effective... Keep the info coming ...thanks!

 

[lollipop]

Pharmacokinetics of vitamin C: insights into the oral and intravenous administration of ascorbate

"[..]repeated oral doses [] may result in sustained plasma ascorbate levels. Keep in mind that the larger the oral vitamin C dose, the more incompletely absorbed from the gut."

"Vitamin C in doses up to 50 grams per day, infused slowly, was not toxic to cancer patients and, even more importantly, some patients had complete remission after high doses following intravenous infusion. Although concentrations that kill most tumor cells (i.e., 200 - 400 mg/dl) were not achieved after infusion of 30 grams of vitamin C, remissions were still observed in patients treated with this dose level, which was assumed by the authors to occur as a result of vitamin C induced biological response modification rather than its cytotoxic potential (40). It could also result from the subject simply having a high level of copper or iron that enhances hydrogen peroxide production by ascorbate in a Fenton-like reaction. The cytotoxic action of vitamin C is greatly enhanced by the presence of synergistic substances such as vitamin K3 or other quinones, lipoic acid, oxygen and futile redox cycling substances."

"Blanchard et al. presented their “ceiling effect” hypothesis for ascorbate pharmacokinetics after megadoses (45). They argued that as the daily oral dose is increased, the background concentration of ascorbate in the plasma and other body compartments does not increase proportionally, but instead tends to approach an upper limit. For example, when the daily dose is increased from 200 to 2,500 mg (1.1 to 14.2 mmol) the peak plasma response increases, but the background concentration increases only from 12 to 15 mg/L (68.1 to 85.2 μM)." "[..]these authors only focus their analysis on pharmacokinetic data from young, healthy male volunteers instead of cancer patients. That is, the implications of the disease-state condition on ascorbate pharmacokinetics must be considered as a factor at the moment of analyzing the pharmacokinetic perspective of [intravenous] megadose use."

"Hickey, Roberts and Cathcart’s paper suggested that the NIH’s misinterpretation of oral ascorbate bioavailability has an impact on the proposed RDA for vitamin C (28). According to the NIH viewpoint, the ascorbate bioavailability is maximized at a dose of 200 mg. This statement assumed a complete absorption of ascorbate by the body at this dose, or at lower intakes whereas a smaller proportion (although a higher absolute amount) will be absorbed after higher doses.
Notably, as Hickey and co-workers pointed out, the short half-life of vitamin C during the rapid excretion phase is sometimes ignored (28). Plasma levels above 70 μM have a half-life of approximately 30 minutes, so large doses taken several hours apart should be considered independent, as should be their bioavailability. This cumulative pattern means that splitting a single large dose into several smaller ones, taken a few hours apart, increases the effective bioavailability of the large dose. This schedule dependence phenomenon needs to be taken into consideration for any further interpretation of ascorbate pharmacokinetic and pharmacodynamic results."

"Cathcart’s bowel tolerance method indicates that individual bioavailability can vary by a factor of at least two orders of magnitude, thus confirming that any variation depends upon the individual’s health status (47). Accordingly, bioavailability is not a static property of ascorbate, but is subject to individual differences and varies with the timing of the dose. It follows that the appropriate intake will vary widely, both between individuals and also over time for the same person, depending on factors such as state of health and intake patterns, among others."

"Blanchard and co-workers published various ascorbate bioavailability values [↓, or ↯ if you're Zeus] calculated from different literature reports (45). The estimated dose-dependent absorbed fractions (bioavailability) using either the mean plasma ascorbate concentrations or the urinary recovery data were observed at daily vitamin C doses ranging from 200 mg (1.1 mmol) to 2,500 mg (14.2 mmol) and from 1 (5.7 mmol) to 12 g (68.1 mmol), in several reference sources.
The tendency for bioavailability to decrease with increasing dose is clearly evident from the literature values cited. However, the magnitudes of the bioavailability values reported in the literature for daily doses higher than 200 mg were considerably greater than the values calculated by Blanchard and co-workers (45). One reason for this discrepancy was proposed by the authors who argued that bioavailability is commonly calculated from the ratio of oral to intravenous AUC, assuming that the AUC is directly proportional to the amount absorbed, which implies constancy of clearance. But plasma ascorbate concentrations are often considerably higher soon after an intravenous dose than after oral administration and consequently the excretion rate of ascorbate would be greater after intravenous dosing than after an equivalent oral input. Because of the nonlinear renal tubular reabsorption, a direct comparison of an oral AUC with an intravenous AUC will produce an overestimation of oral bioavailability.
In addition, the oral bioavailability estimates reported in the literature may be somewhat biased because they are frequently based on the assumption that the rate of ascorbate absorption is linear and therefore the nonlinear carrier-mediated absorption is often ignored. Likewise, multiple oral doses are expected to produce fluctuations in the absorption rate. Despite the uncertainty in the estimation of oral bioavailability, the analysis suggests that plasma ascorbate concentrations largely depend on limited absorption, probably as a result of a saturable transport mechanism."

"[Due to saturable absorption,] the bioavailability of ascorbate will be increased when given in divided doses or concurrently with food (48)."

"[..]the depletion of tissue ascorbate in cancer and other chronic diseases is associated with an excessive catabolism of proteins (11, 50)."

"Ascorbate can generate hydrogen peroxide upon oxidation in biological systems. This action can be enhanced by divalent cations such as iron and copper. Hydrogen peroxide may further generate additional reactive species and secondary products of oxidation. In general, the cytotoxicity induced by ascorbate seems to be primarily mediated by hydrogen peroxide formation."

"Reviewing the current literature, most studies have used single large daily, or twice-a-day, doses of vitamin C. Occasional studies have used low-dose, slow release formulations. A large single daily dose will produce only a transient increase in plasma levels. Such once or twice daily mega-dose supplementation of ascorbate will not load tissues, such as red blood cells, or increase the body pool substantially; and therefore, would not be expected to show more than a minimal biological effect, when compared with the dynamic flow model."​

[45] Pharmacokinetic perspectives on megadoses of ascorbic acid

View attachment 9359​

For a laxative effect: single bolus dose.
For sustaining high vitamin C levels: spread dose throughout the day, it might be possible to achieve better results using much less in total.

Great post here @Amazoniac. I like how it references the 50gm for cancer that I had heard the doctor in Britain was having success putting cancer into remission.

 

[2thecloudsabove]

It could also result from the subject simply having a high level of copper or iron that enhances hydrogen peroxide production by ascorbate in a Fenton-like reaction. The cytotoxic action of vitamin C is greatly enhanced by the presence of synergistic substances such as vitamin K3 or other quinones, lipoic acid, oxygen and futile redox cycling substances."

"Ascorbate can generate hydrogen peroxide upon oxidation in biological systems. This action can be enhanced by divalent cations such as iron and copper. Hydrogen peroxide may further generate additional reactive species and secondary products of oxidation. In general, the cytotoxicity induced by ascorbate seems to be primarily mediated by hydrogen peroxide formation."

"In addition, our findings might explain the mechanism for the protective effect of iron against vitamin C induced cell toxicity."

Iron prevents ascorbic acid (vitamin C) induced hydrogen peroxide accumulation in copper contaminated drinking water

​

 

[Frankdee20]

Does anyone get a mood elevating effect from Vitamin C ? I take Sodium Ascorbate powder, non GMO, from the UK.

What are the mechanisms behind this ? Lowered COMT enzyme, cortisol, Tyrosine Hydroxylase, norepinephrine synthesis ?

 

[Amazoniac]

From 'The conquest of cancer' by Virginia of the livingstons:
"[Guineae pigs have] a natural [?] immunity and are resistant to cancer. Only 1 guineae pig in 500,000 develops cancer spontaneously."

 

[InChristAlone]

Does anyone get a mood elevating effect from Vitamin C ? I take Sodium Ascorbate powder, non GMO, from the UK.

What are the mechanisms behind this ? Lowered COMT enzyme, cortisol, Tyrosine Hydroxylase, norepinephrine synthesis ?

I thought I read it could be norepinephrine.

 

[yerrag]

From 'The conquest of cancer' by Virginia of the livingstons:
"[Guineae pigs have] a natural [?] immunity and are resistant to cancer. Only 1 guineae pig in 500,000 develops cancer spontaneously."

Why do they have a natural immunity to cancer? And it's interesting to note that guinea pigs need vitamin C, just as humans do, because they can't produce it themselves.

 

[Frankdee20]

I thought I read it could be norepinephrine.

Yes, online data suggests it effects beta hydroxlylase enzyme that converts Dopamine to Norepinephrine.

 

[InChristAlone]

From 'The conquest of cancer' by Virginia of the livingstons:
"[Guineae pigs have] a natural [?] immunity and are resistant to cancer. Only 1 guineae pig in 500,000 develops cancer spontaneously."

Maybe they just don't live long enough? How many animals even get cancer? When I had guinea pigs I had one who grew a large tumor. I probably didn't take care of him well enough.

 

[Amazoniac]

Why do they have a natural immunity to cancer? And it's interesting to note that guinea pigs need vitamin C, just as humans do, because they can't produce it themselves.

I don't know. But..

Maybe they just don't live long enough? How many animals even get cancer? When I had guinea pigs I had one who grew a large tumor. I probably didn't take care of him well enough.

I wonder how you manage to post and read threads. Is it while you're getting ready at the runway backstage? You might miss your turn and Carolina Herrera is going to be very upset.

I think she was comparing with other rodents such as mice.

..I suspect it has something to do with mice being abused in research more so than guinea pigs, which might be less stressed for generations. This includes reduction in pathogens exposure.

 

[InChristAlone]

I don't know. But..

I wonder how you manage to post and read threads. Is it while you're getting ready at the runway backstage? You might miss your turn and Carolina Herrera is going to be very upset.

I think she was comparing with other rodents such as mice.

..I suspect it has something to do with mice being abused in research more so than guinea pigs, which might be less stressed for generations. This includes reduction in pathogens exposure.

Hahaha you flatter me!

 

[Amazoniac]

Didn't read but seems interesting:
Inhibiting Effect of Sodium Chloride on the Oxidation of Ascorbic Acid (cooking)

 

[Amazoniac]

The effect of chronic marginal vitamin C deficiency on the α-tocopherol content of the organs and plasma of guinea-pigs

"We undertook this study to ascertain whether the assumed synergism between vitamins C and E and changes in the lipid metabolism caused by a prolonged latent vitamin C deficiency [8] induce changes in a-tocopherol levels in the blood and organs of guinea-pigs exposed to marginal vitamin C deficiency over a long period."

"Prolonged vitamin C deficiency resulted in a decrease of a-tocopherol concentration in the liver, lungs and kidneys to approximately a half of the control values; its concentration in testes, epididymal fat and blood plasma did not change significantly (table)."

"There is [] growing evidence of the interaction of the 2 vitamins in animal tissues. In some conditions, vitamin C can improve a-tocopherol metabolism; in others it may increase the demand of the body for vitamin E [18-20]."

"Decreased a-tocopherol content in the liver, lungs and kidneys of guinea-pigs with chronic marginal vitamin C deficiency suggests that in these organs a-tocopherol replaced the missing ascorbic acid in some redox-processes. There is also a possibility that in conditions of long-lasting low ascorbate levels in the above organs a tocopherol is more susceptible to oxidation to quinons.

"In the light of known relations between the plasma levels of lipids and vitamin E [4-6], the absence of changes in the plasma level of vitamin E in vitamin C-deficient guinea pigs, which showed a nearly 4-fold increase in triglyceridaemia, is surprising."

"The results suggest that chronic marginal deficiency of vitamin C can lead also to relative deficiency of vitamin E."

 

[lollipop]

The effect of chronic marginal vitamin C deficiency on the α-tocopherol content of the organs and plasma of guinea-pigs

"We undertook this study to ascertain whether the assumed synergism between vitamins C and E and changes in the lipid metabolism caused by a prolonged latent vitamin C deficiency [8] induce changes in a-tocopherol levels in the blood and organs of guinea-pigs exposed to marginal vitamin C deficiency over a long period."

"Prolonged vitamin C deficiency resulted in a decrease of a-tocopherol concentration in the liver, lungs and kidneys to approximately a half of the control values; its concentration in testes, epididymal fat and blood plasma did not change significantly (table)."

"There is [] growing evidence of the interaction of the 2 vitamins in animal tissues. In some conditions, vitamin C can improve a-tocopherol metabolism; in others it may increase the demand of the body for vitamin E [18-20]."

"Decreased a-tocopherol content in the liver, lungs and kidneys of guinea-pigs with chronic marginal vitamin C deficiency suggests that in these organs a-tocopherol replaced the missing ascorbic acid in some redox-processes. There is also a possibility that in conditions of long-lasting low ascorbate levels in the above organs a tocopherol is more susceptible to oxidation to quinons.

"In the light of known relations between the plasma levels of lipids and vitamin E [4-6], the absence of changes in the plasma level of vitamin E in vitamin C-deficient guinea pigs, which showed a nearly 4-fold increase in triglyceridaemia, is surprising."

"The results suggest that chronic marginal deficiency of vitamin C can lead also to relative deficiency of vitamin E."

Hello @Amazoniac, I remember one of your posts from quite a long time ago concerning Vit C consumption. At that point you felt 1000mg a day was a safe balanced amount. Is this still where you land on this issue?

 

[Amazoniac]

Hello @Amazoniac, I remember one of your posts from quite a long time ago concerning Vit C consumption. At that point you felt 1000mg a day was a safe balanced amount. Is this still where you land on this issue?

500-1000 mg spread throughout the day is what I would consider if taste is somewhat blunted and unreliable for some reason. It can be adjusted based on reactions but it's better through cravings and just ignore the ranch.
There's now an impostor around: lisalisa.

 

[lollipop]

500-1000 mg spread throughout the day is what I would consider if taste is somewhat blunted and unreliable for some reason. It can be adjusted based on reactions but it's better through cravings and just ignore the ranch.
There's now an impostor around: lisalisa.

Great, thank you @Amazoniac...

LoL...looking out for this shameless imposter lisalisa

 

[Mito]

DNA Methylation, Aging, And Cancer

 

[Amazoniac]

Why are you taking so much?


Am J Clin Nutr. 1997 Nov;66(5):1165-71.
Pharmacokinetic perspectives on megadoses of ascorbic acid.
Blanchard J1, Tozer TN, Rowland M.
Author information
Abstract
Ascorbic acid (vitamin C) is commonly used as a dietary supplement, often in megadoses. However, as the daily oral dose is increased, the concentration of ascorbic acid in the plasma and other body fluids does not increase proportionally, but instead tends to approach an upper limit. For example, when the daily dose is increased from 200 to 2500 mg (from 1.1 to 14.2 mmol) the mean steady state plasma concentration increases only from approximately 12 to 15 mg/L (from 68.1 to 85.2 mumol/L). Published data were reanalyzed with an integrated modeling approach to shed new quantitative light on this phenomenon. This analysis is based on the renal clearance of ascorbic acid, which rises sharply with increasing plasma concentrations as a result of saturable tubular reabsorption. The analysis indicates that both saturable gastrointestinal absorption and nonlinear renal clearance act additively to produce the ceiling effect in plasma concentrations. As a consequence of this ceiling effect, there is no pharmacokinetic justification for the use of megadoses of ascorbic acid.

Pharmacokinetic perspectives on megadoses of ascorbic acid. - PubMed - NCBI

Spoiler

Orange: other studies
Yellow: current study

For comparison:
1x 1000 mg at 40% → 400 mg.
2x 250 mg at 85% → 210 mg * 2 → 420 mg.

Talk about contaminant exposure minimization!
Hopefully it doesn't increase the efficiency of their absorption as well.