Verdict
Conflicting
Vitamin C supplements boost immune function.
3 sources: 1 positive, 1 partly, 1 negative
By Arun AgrahriLast reviewed 1 timecoded source
Short answer
To a degree, and mostly when you are low. Rhonda Patrick backs vitamin C for immune and heart health in a dedicated deep-dive, and Mark Hyman recommends it widely. The effect on colds is small. Absorption from a single oral dose plateaus quickly, though blood levels still rise briefly at higher doses.
Vitamin C supplements are worth taking.
The verdict on Vitamin C overall. 5 sources: 1 positive, 3 partly, 1 neutral
positive partly neutral negative Each researcher and each study counts once per claim, however often they come up.
Vitamin C supplements boost immune function.
3 sources: 1 positive, 1 partly, 1 negative.
Researchers say
1 positive, 1 partly, 1 negative
Mark Hyman, on The Dr. Hyman Show, at 01:25
Positive Video · Opinion
Open the tape at 01:25 →“I don't think I've ever gotten the flu because I take the supplements I take vitamins I take zinc I take vitamin C”
Dr. Andy Galpin, on FoundMyFitness, at 2:07:18
Partly Video · Opinion
Open the tape at 2:07:18 →“for any kind of immune support that we can have. I I'm not I do not hesitate to go to a gram of vitamin C.”
Jenna Macciochi, on Rangan Chatterjee's channel, at 04:19
Negative Video · Opinion
Open the tape at 04:19 →“so take a vitamin c supplement or eat these vitamin c rich foods and i kind of just wanted to emphasize it's not that simple”
Studies show
No study counted yet.
Mark Hyman, on The Dr. Hyman Show, at 01:25 Video · positive · Opinion
“I don't think I've ever gotten the flu because I take the supplements I take vitamins I take zinc I take vitamin C”
Dr. Andy Galpin, on FoundMyFitness, at 2:07:18 Video · partly · Opinion
“for any kind of immune support that we can have. I I'm not I do not hesitate to go to a gram of vitamin C.”
Jenna Macciochi, on Rangan Chatterjee's channel, at 04:19 Video · negative · Opinion
“so take a vitamin c supplement or eat these vitamin c rich foods and i kind of just wanted to emphasize it's not that simple”
Vitamin C supplements boost immune function.
Mark Hyman, on The Dr. Hyman Show, at 01:25
Positive Video · Opinion
Open the tape at 01:25 →“I don't think I've ever gotten the flu because I take the supplements I take vitamins I take zinc I take vitamin C”
Dr. Andy Galpin, on FoundMyFitness, at 2:07:18
Partly Video · Opinion
Open the tape at 2:07:18 →“for any kind of immune support that we can have. I I'm not I do not hesitate to go to a gram of vitamin C.”
Jenna Macciochi, on Rangan Chatterjee's channel, at 04:19
Negative Video · Opinion
Open the tape at 04:19 →“so take a vitamin c supplement or eat these vitamin c rich foods and i kind of just wanted to emphasize it's not that simple”
Precis is not affiliated with or endorsed by YouTube or by any researcher, show or publisher we quote. We take no sponsorship, ad or affiliate money, and every verdict is our own review of what was said. How we stay independent
Vitamin C supplements support immune function, but far less than the bottle implies. Rhonda Patrick has a whole deep-dive on it, covering oral and IV forms, and backs it for immune and heart health. Mark Hyman recommends it across dozens of videos for immune support, stress and detoxification. Bryan Johnson takes it daily, next to iron.
Patrick explains that vitamin C's absorption from a single dose maxes out and then falls at higher doses. That is not the end of it, though. Blood levels still rise after higher oral doses, with short-lived peaks two to three times higher, before returning to baseline within a day.
Peter Attia is the brake. He argues that mega-dosing buys nothing once you are past a deficiency. Andrew Huberman finds only a small effect on preventing colds.
The disagreement is about dose, not the vitamin. Getting enough matters, and fruit and vegetables get most people there. A 1000mg pill on top of that adds little immune cover; 200-500mg a day from food and pills covers most needs.
Precis membership
The answer above is the whole answer: the verdict, every counted mention, where the sources disagree, and the receipt behind each one. Nothing on this page is held back.
A free account adds
Pro adds
Full Vitamin C evidence report
The verdict on every claim, and where the sources disagree