Dehydroascorbic acid

VitaminVitamin C form

What is it

Dehydroascorbic acid (DHA) is the oxidized form of vitamin C (ascorbic acid). It is converted to and from ascorbic acid in the body and serves as a transient form during vitamin C's antioxidant activity.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Vitamin C status

Strong Evidence

Vitamin C in either form prevents and treats vitamin C deficiency (scurvy) and supports collagen synthesis and immune function.

How it works

When ascorbic acid donates electrons (its antioxidant role), it becomes dehydroascorbic acid. Inside cells and red blood cells, DHA can be reduced back to ascorbic acid by glutathione-dependent enzymes, recycling the molecule. Interestingly, DHA crosses cell membranes through glucose transporters (GLUT1), which is different from ascorbic acid's uptake via sodium-vitamin C transporters. This has prompted research interest, particularly regarding brain delivery, since GLUT1 transporters function at the blood-brain barrier.

Dosage

There is no separate RDA for DHA; vitamin C as a whole has an RDA of 90 mg/day for adult men and 75 mg/day for adult women. As a stand-alone ingredient, DHA is uncommon; most products use ascorbic acid or mineral ascorbates.

When and how to take it

Vitamin C is water-soluble; smaller divided doses generally absorb better than a single large dose. Can be taken with or without food.

2 commercial forms

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Dehydroascorbic acid (research)

Uncommon as a stand-alone supplement form.

Enters cells via glucose transporters; rapidly reduced to ascorbate intracellularly.

Ascorbic acid (standard vitamin C)

Used in most vitamin C products.

Most common supplemental form; equivalent for nutritional purposes.

Safety

DHA is essentially equivalent to vitamin C in terms of nutritional and safety profile, since the two forms interconvert in the body. Vitamin C above 2000 mg/day can cause GI upset and increase oxalate excretion. DHA has been studied at high parenteral doses in research, with potential pro-oxidant effects at very high concentrations.

Who should be cautious

People with hemochromatosis, G6PD deficiency, or kidney stones should avoid high-dose vitamin C in any form. Standard supplement doses are safe for most people.

Interactions

Same as ascorbic acid: very high doses may affect lab tests, slightly enhance iron absorption, and interact with certain chemotherapy drugs and anticoagulants at extreme doses.

Food sources

Bell pepper, red

Amount
1/2 cup
%DV
105%

Citrus fruits

Amount
1 medium orange
%DV
78%

Strawberries

Amount
1 cup
%DV
108%

Frequently asked questions

Is dehydroascorbic acid different from regular vitamin C?⌄

It is the oxidized form, and the two interconvert in the body. Nutritionally, the body treats them as equivalent.

Should I look for dehydroascorbic acid on labels?⌄

It is rare on labels. Standard ascorbic acid works for the same purposes.

References

Dehydroascorbic acid on Wikidata — Wikidata link

Dehydroascorbic acid (ChEBI:27956) — ChEBI link

Dehydroascorbic acid (PubChem CID 440667) — PubChem link

Dehydroascorbic acid on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Dehydroascorbic acid (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.