Ascorbic acid (vitamin C)

[Persej]

There is also another way:

We have previously shown that vitamin C (ascorbic acid) can initiate hydroxyl radical formation in copper contaminated household drinking water. In the present study, we have examined the stability of vitamin C in copper and bicarbonate containing household drinking water. In drinking water samples, contaminated with copper from the pipes and buffered with bicarbonate, 35% of the added vitamin C was oxidized to dehydroascorbic acid within 15 min. After 3 h incubation at room temperature, 93% of the added (2 mM) ascorbic acid had been oxidized. The dehydroascorbic acid formed was further decomposed to oxalic acid and threonic acid by the hydrogen peroxide generated from the copper (I) autooxidation in the presence of oxygen. A very modest oxidation of vitamin C occurred in Milli-Q water and in household water samples not contaminated by copper ions. Moreover, addition of vitamin C to commercially sold domestic bottled water samples did not result in vitamin C oxidation. Our results demonstrate that ascorbic acid is rapidly oxidized to dehydroascorbic acid and further decomposed to oxalic- and threonic acid in copper contaminated household tap water that is buffered with bicarbonate. The impact of consuming ascorbic acid together with copper and bicarbonate containing drinking water on human health is discussed.

https://www.tandfonline.com/doi/abs/10.1080/10715760410001700497

Under the cell-free condition, copper is known to oxidize ascorbic acid (the active form of vitamin C) and the event leads to the loss of vitamin C. However, the biological consequence of this interaction was never examined in the presence of cells. We demonstrated in intestinal epithelial cells that dehydroascorbic acid (the oxidized form of ascorbic acid), when generated from ascorbic acid in the presence of copper, can be efficiently transported into the cells and reduced back to ascorbic acid. We also observed in other types of cells the transport and intracellular reduction of dehydroascorbic acid in the presence of copper. In the presence of iron, a metal that also oxidizes ascorbic acid, we observed similar oxidation-related accumulation in intestinal cells. Other metals that do not interact with ascorbic acid had little effect on vitamin C transport. A nonmetal pro-oxidant, hydrogen peroxide, is known to oxidize ascorbic acid and we observed that the oxidation is also accompanied by an increased intracellular accumulation of vitamin C. The efficient coupling between dehydroascorbic acid transport and intracellular reduction could help to preserve the important nutrient when facing oxidative metals in the intestine.

Cellular vitamin C accumulation in the presence of copper - PubMed

Under the cell-free condition, copper is known to oxidize ascorbic acid (the active form of vitamin C) and the event leads to the loss of vitamin C. However, the biological consequence of this interaction was never examined in the presence of cells. We demonstrated in intestinal epithelial cells...

pubmed.ncbi.nlm.nih.gov

They mentioned that first-draw water used in the morning can be contaminated by copper ions:

Samples from drinking water fountains in 50 schools in New Jersey were collected at specific times during a typical school day and analyzed for lead, copper, pH, alkalinity, and hardness. First-draw lead and copper levels (medians 0.010 mg/l and 0.26 mg/l, respectively) decreased significantly after 10 min of flushing in the morning (medians 0.005 mg/l lead and 0.068 mg/l copper), but levels increased significantly by lunchtime (medians 0.007 mg/l lead and 0.12 mg/l copper) after normal use of fountains in the morning by students. Corrosive water, as defined by the aggressive index, contained significantly higher levels of lead and copper (medians 0.012 mg/l and 0.605 mg/l, respectively) than noncorrosive water (medians 0.005 mg/l and 0.03 mg/l, respectively).

Effectiveness of flushing on reducing lead and copper levels in school drinking water - PubMed

Samples from drinking water fountains in 50 schools in New Jersey were collected at specific times during a typical school day and analyzed for lead, copper, pH, alkalinity, and hardness. First-draw lead and copper levels (medians 0.010 mg/l and 0.26 mg/l, respectively) decreased significantly...

pubmed.ncbi.nlm.nih.gov

Daily intake of copper from drinking water among young children in Sweden - PubMed

Copper is an essential trace element that may cause intoxication if intake becomes excessive. Young children are at risk of intoxication because of high consumption of drinking water and immature copper metabolism. The aims of this prospective study were to estimate concentrations of copper in...

pubmed.ncbi.nlm.nih.gov

Some of you could be already consuming a lot of dehydroascorbic acid because you have a lot of copper in your tap water. But if you want more copper, there is an option of ayurvedic copper bottles.

 

[daddycat]

Another way to make dehydroascorbic acid is to mix ascorbic acid with iodine

Good old orange juice and Lugol's.

 

[Persej]

Good old orange juice and Lugol's.

Yes, but some would say that it's a waste of iodine. And in fact it is certainly a waste of copper because vitamin C decreases absorption of copper, which can be a problem for people who have a lack of copper in their diet.

I tried a green tea with vitamin C combination and all it did was giving me a short headache. Perhaps something was getting inside my brain but I didn't like it. Perhaps the best way to take vitamin C would be to mix it with some fresh fruit juice that has those enzymes in it that will turn ascorbic acid into DHA.

 

[daddycat]

Yes, but some would say that it's a waste of iodine.

I'm fine with wasting iodine. Do you agree dehydroascorbic acid is made with orange juice and Lugol's?

 

[Persej]

Do you agree dehydroascorbic acid is made with orange juice and Lugol's?

Yes, but you would need too much iodine for that, so it's not practical.

It seems that the best results you could get is to either mix orange juice with some other fruit or vegetable that has plenty of ascorbic acid oxidizing enzymes, or just let it stand in the air and UV light for some time.

Some suggestions by ChatGPT:

A smoothie offers an ideal environment for enzymatic oxidation due to:

• High surface area (from blending)
• Mixed enzyme sources
• Oxygen availability
• pH and temperature compatible with enzyme activity

You can use fruits like banana, zucchini, pumpkin, cucumber, or spinach to naturally oxidize ascorbic acid. These contain ascorbate oxidase or polyphenol oxidase, which work in the presence of oxygen.

Good options:

• Banana – very active PPO (browning)
• Zucchini or cucumber – good AAO activity
• Pumpkin (raw) – strong AAO
• Spinach – contains AAO and trace metals
• Apple – moderate PPO
• Papaya or mango – milder AAO
• Avocado – active peroxidase/PPO

Avoid:

• Highly acidic fruits (lemon, pineapple) — they slow enzyme activity
• Pasteurized juices or cooked ingredients — enzymes are deactivated

I posted before this video about mixing ascorbic acid with zucchini. The ideal temperature for AAO enzyme is 40 degrees Celsius. So a lemonade with warm alkaline water is another good option, but anything above 40C will deactivate enzymes.

 

[Persej]

The interaction of glutathione (GSH) with ascorbic acid and dehydroascorbic acid was examined in in-vitro experiments in order to examine the role of GSH in protecting against the autoxidation of ascorbic acid and in regenerating ascorbic acid by reaction with dehydroascorbic acid. If a buffered solution (pH 7.4) containing 1.0 mM ascorbic acid was incubated at 37 degrees C, there was a rapid loss of ascorbic acid in the presence of oxygen. When GSH was added to this solution, ascorbic acid did not disappear. Maximum protection against ascorbic acid autoxidation was achieved with as little as 0.1 mM GSH. Cupric ions (0.01 mM) greatly accelerated the rate of autoxidation of ascorbic acid, an effect that was inhibited by 0.1 mM GSH. Other experiments showed that GSH complexes with cupric ions, resulting in in a lowering of the amount of GSH in solution as measured in GSH standard curves. These results suggest that the inhibition of ascorbic acid autoxidation by GSH involves complexation with cupric ions that catalyze the reaction. When ascorbic acid was allowed to autoxidize at 37 degrees C the subsequent addition of GSH (up to 10 mM) did not lead to the regeneration of ascorbic acid. This failure to detect a direct reaction between GSH and the dehydroascorbic acid formed by oxidation of ascorbic acid under this condition was presumably due to the rapid hydrolysis of dehydroascorbic acid. When conditions were chosen, i.e., low temperature, that promote stability of dehydroascorbic acid, the direct reaction between GSH and dehydroascorbic acid to form ascorbic acid was readily detected. The marked instability of dehydroascorbic acid at 37 degrees C raises questions regarding the efficiency of the redox couple between GSH and dehydroascorbic acid in maintaining the concentration of ascorbic acid in mammalian cells exposed to an oxidative challenge.

In vitro oxidation of ascorbic acid and its prevention by GSH - PubMed

The interaction of glutathione (GSH) with ascorbic acid and dehydroascorbic acid was examined in in-vitro experiments in order to examine the role of GSH in protecting against the autoxidation of ascorbic acid and in regenerating ascorbic acid by reaction with dehydroascorbic acid. If a buffered...

pubmed.ncbi.nlm.nih.gov

The Antioxidant Effects of Glutathione and Ascorbic Acid

The functions of glutathione have been explored by use of a model animal system in which the cellular synthesis of glutathione is inhibited. Glutathione deficiency, induced by administration of buthionine sulfoximine (an inhibitor of the first step of glutathione...

link.springer.com

Since glutathione is the thing that converts dehydroascorbic acid into ascorbic acid, then taking anything that reduces glutathione would increase the amount of dehydroascorbic acid. That could explain why some people like taking vitamin C. Perhaps they naturally have low amounts of glutathione in their body, so the vitamin C can more easily get inside their brain?