I want to tell you about a molecule that the medical establishment treats as a quaint footnote — the thing in your orange juice, the chewable tablet your nan gave you when you had a cold — and how, over the course of a series of interviews on Pushing The Limits, I came to understand it as one of the most powerful, most under-used tools we have in critical illness.

And I want to be honest with you about why this subject is not academic for me. I fought a 15-day battle in an ICU to get intravenous vitamin C for my father while he was dying of sepsis, and I lost. So when I talk about vitamin C, I'm not talking theory. I'm talking about something I believe could have changed an outcome that still keeps me up at night.

Over a remarkable run of episodes I sat down with five of the people who actually know this molecule from the inside: Dr Thomas Levy, Dr Ron Hunninghake, Professor Margreet Vissers, Dr Anitra Carr, and Dr Alpha "Berry" Fowler.

Between them they represent something like a century and a half of vitamin C research. Here's what they taught me, woven together — because individually each interview is powerful, but together they tell a story that should change how every hospital on earth treats acute illness.

Dr Thomas Levy: the cardiologist-lawyer who saw something "that couldn't happen"

Dr Thomas Levy is one of the most renowned vitamin C researchers and physicians in the world — and, improbably, a board-certified cardiologist and a lawyer. His journey began when he wound down a conventional cardiology practice and met Dr Hal Huggins, the pioneering biological dentist, in Colorado Springs. At Huggins's clinic, Levy watched things happen that, in his words, in med school "you're taught don't exist." He saw patients who'd been wheelchair-bound with MS for over a year take a few steps at the end of two weeks.

But the thing that truly hooked him was an elderly woman with advanced neurological disease who underwent hours of major dental extractions — the kind of work that puts a healthy college kid in bed for a week — and walked out energised. Levy turned to Huggins and asked what on earth was going on. Huggins, a dry, sarcastic man, just pointed at the IV.

"It's what's in it." "Okay, Hal, what's in it?" "50 grams of vitamin C."

As Levy put it, that came from left field and smacked him between the eyes. He decided he wasn't going to be "misled by my lying eyes" — something real had happened — and that moment launched 40 years of research into vitamin C and the book that became his calling card, Curing the Incurable. You can hear the whole story in our conversation, Curing the Incurable with Vitamin C with Dr Thomas Levy MD, JD.

Levy's unified theory of disease is elegant in its simplicity: all disease is driven by increased oxidative stress; toxins are the primary driver of that oxidative stress; and chronic, hidden infections are the primary source of those toxins. I explored this in depth in my article Why Calcium Might Be Killing You, but the centrepiece is a concept he calls focal scurvy. In 2006 a German researcher, Dr Stephan Ott, used catheter-based atherectomy to remove plaque from the arteries of 38 patients with coronary artery disease. In 100% of patients he found bacterial DNA — over 50 different species, many of them oral bacteria. Every single one.

Here's Levy's mechanism: pathogens colonise the arterial wall, produce toxins, and those toxins consume antioxidants — particularly vitamin C — until the local level inside that segment of blood vessel hits zero. That vessel is now in a state of localised, acute vitamin C deficiency: focal scurvy. Your monocytes, the first-responder immune cells, rush in carrying 8,000% more vitamin C than other cells in the body. But if the source infection — often chronic dental infections, root canals, gum disease — is never addressed, the acute response becomes chronic, plaque builds, and the body is left doing its best with a terrible situation. It reframes heart disease entirely: the plaque isn't just a cholesterol deposit, it's a chronic infection colony.

IV, oral, or liposomal? Levy's answer: "all of them"

When I asked Levy the question everyone wants answered — intravenous versus oral versus liposomal — his reply was immediate. "When somebody says, what would you use? My answer is all of them." If he's sick, he's not going to arbitrarily pick one. They each make a unique contribution.

Intravenous lets you get an extremely large amount of vitamin C into the body very quickly, at a concentration you simply cannot reach any other way. But — and this is the subtle bit — vitamin C in the blood still has to consume cellular energy to get inside the cell in its reduced form. This is where liposomal vitamin C is so clever. A liposome is a tiny fat globule, a cell-like structure, with the same construction as your natural cell membranes. It gets absorbed almost completely and promptly in the gut, unlike other oral forms, and once it's circulating, the liposomes can get inside the cell without consuming energy.

I raised my own concern: the omega-6 load. We already run wildly skewed omega-6 to omega-3 ratios, so was I doing harm giving my mum a lot of liposomal vitamin C? Levy put me at ease. The lipid in a quality liposome — he specifically named the LivOn product, warning there are a lot of fraudulent liposomes out there — is phosphatidylcholine, identical to the phosphatidylcholine in your own cell walls. As he put it, the liposome itself is a positive supplement, on top of what's inside it. The full discussion of delivery methods is in the Levy interview.

Dr Ron Hunninghake: the Riordan protocol and the "quantum mechanics" of ascorbic acid

Before Levy, I'd had Dr Ron Hunninghake from the Riordan Institute on the show, and that conversation laid the foundation for everything that followed. You can listen to it here: The Power of Intravenous Vitamin C with Dr Ron Hunninghake.

Ron told the story of Dr Hugh Riordan, who picked up the flag after Linus Pauling — the double Nobel laureate who was ridiculed for his vitamin C work despite winning unshared prizes in chemistry and peace — and procured a million-dollar grant to launch RECNAC ("cancer" spelled backwards). Riordan's groundbreaking work showed that in cell culture, adequate amounts of vitamin C would effectively stop the growth of cancer cells, and from that came the Riordan protocol now used by doctors all over the world — New Zealand, Australia, a thousand doctors in Japan, extensive research in China.

The crucial insight, Ron explained, is dose and pharmacokinetics. As he put it, there's almost a quantum mechanics of ascorbic acid — at higher levels it does entirely different things. Given intravenously at high doses, vitamin C is, in his words, "a completely different beast" than the tablet or the orange you have at breakfast. He told me about a friend who asked her surgeon whether she should have IV vitamin C before surgery, and was told "no, just have an orange." That misunderstanding, Ron said, is exactly the problem.

Importantly, Ron didn't want to write off oral vitamin C at all. He cited Dr Robert Cathcart, who gave students with mono six to ten grams of ascorbic acid every hour for days — over 100 to 150 grams orally — without diarrhoea, because when you're sick your bowel tolerance soars. And he reminded me that Pauling's original protocol was 10 grams a day by slow infusion for 10 days, then 2.5 grams four times a day orally, on which he helped stage three and four cancer patients live four to nine times longer. That figure is contested — when the Mayo Clinic tried to replicate it and found nothing, it became the standard rebuttal — but those trials used oral vitamin C only, never the intravenous route the original work began with, and with vitamin C, as Ron kept stressing, that distinction changes everything. Ron's framing has stuck with me: high-dose IV vitamin C is like ICU intensive care, but chronic oral dosing matters too — if you don't have access to IV, you're not out of luck, you just need to dose more frequently.

He was also candid about why this is such a fight. Vitamin C is an oxidative therapy, in the same family as hyperbaric oxygen and ozone — and when something comes from a completely different direction to the accepted paradigm, the medical community resists it. He talked about functional doctors being investigated constantly, about how the ones at the forefront of knowledge are the ones getting their heads chopped off if they pop above the parapet. "You can waste a lot of energy," he said, "coming up against brick walls." I knew exactly what he meant.

Professor Margreet Vissers: the immune and cancer science

On the science of why vitamin C matters at the cellular level, the work of Professor Margreet Vissers at the University of Otago is foundational. You can hear her explain it in our interview, Professor Margreet Vissers on Pushing The Limits, and I've drawn on it across my writing, including Unveiling Vitamin C: Decoding Its Profound Impact on Health.

Vissers's research highlights two things that matter enormously here. First, immune function: white blood cells are extraordinarily rich in vitamin C, and adequate levels help them operate effectively — clearing infections and, just as importantly, resolving the inflammation afterwards. Second, cancer: her work shows vitamin C may influence cancer cell behaviour by regulating the hypoxia-inducible factors (HIF), the proteins cancer cells rely on to survive in low-oxygen environments. Tumours thrive by creating poorly oxygenated environments that trigger HIF activity; vitamin C modulates that response, potentially slowing tumour growth by inhibiting the new blood vessel formation tumours depend on. She also points to vitamin C's role in improving chemotherapy tolerance — easing fatigue, nausea and cognitive decline during treatment.

Dr Anitra Carr: our own Kiwi scientist, and why dose and timing are everything

Dr Anitra Carr from Christchurch is one of our own — a New Zealand scientist doing world-class work, much of it as a genuine labour of love against thin funding. Her path runs straight through the Linus Pauling legacy: after her PhD at Otago she did a postdoc under Balz Frei, who became director of the Linus Pauling Institute. Our conversation is here: Vitamin C for Sepsis & Critical Illness with Dr Anitra Carr.

Anitra put the scale of the problem in stark terms. Around 50 million people a year develop sepsis, and roughly one in five patients in New Zealand ICUs dies of it. This is as big as cancer — and it's often a complication of cancer therapy itself. Her observational studies recruited pneumonia and sepsis patients and measured their vitamin C: the levels were very low, and the more severe the condition, the lower the vitamin C and the higher the oxidative stress. Many were sitting just above the scurvy threshold. As she put it, their bodies are quite literally falling apart, on top of the sepsis itself.

And here's the scandal: the standard recommended amount of vitamin C for an ICU patient is about 100 milligrams a day. In a healthy person that's plenty. But in critical illness the body's requirement goes up at least 30-fold, even a hundredfold. She mapped what these patients' blood levels should have been based on intake, then measured what was actually there — and it was way lower than even that. They're being given a dose that doesn't touch the sides.

The mechanistic part of her work that floored me was vitamin C's role as a cofactor for the enzymes that synthesise noradrenaline and vasopressin — the very vasopressors doctors inject to hold up a septic patient's collapsing blood pressure. If a patient arrives depleted in vitamin C, part of the reason they're crashing may be that they can't make their own vasopressors. Give vitamin C early enough and you may support the body's own regulated production, instead of relying on high, unregulated doses of external drugs with all their side effects. She also walked me through vitamin C's epigenetic role — as a cofactor for the TET enzymes that modify DNA methylation, potentially regulating thousands of genes.

Her practical message was unambiguous: dose matters, timing matters, and duration matters. Give it as early as possible — don't wait until someone is in septic shock at death's door, because it's hard for even a high-dose vitamin to work at that stage. And don't stop at 96 hours, which is where most trials cut off; pharmacokinetic data shows that when you stop, some patients drop straight back down to where they started. They need continued input.

Dr Berry Fowler, CITRIS-ALI, and the trial that should have changed everything

Then came Dr Alpha "Berry" Fowler, professor of medicine in pulmonary and critical care at Virginia Commonwealth University, and the man behind the landmark CITRIS-ALI trial. Our interview is here: IV Vitamin C for Sepsis & ARDS with Dr Alpha Berry Fowler.

Fowler's interest began at the molecular level and led to an animal model of sepsis that he described with relish: take 30-gram mice, inject a faecal-bacteria slurry into the peritoneum, and watch what happens. He came in at six the next morning to find the control septic mice all dead in their cage — and in the next cage, the septic mice that had received vitamin C were crawling around, drinking water and eating. That's when he knew they'd stumbled onto something significant.

From there he established the mechanism: in sepsis, neutrophils disgorge their own DNA into the extracellular space, forming traps; the level of that cell-free DNA in the circulation is a known predictor of mortality. When Fowler's team re-analysed the blood from the CITRIS-ALI patients, they found vitamin C dramatically lowered cell-free DNA in the treated patients. Vitamin C protected the lungs, preserved barrier function, and shut down the inflammatory protein cascade that the septic lung produces.

On dosing, the CITRIS-ALI protocol gave a patient of around my size roughly 3.5 grams intravenously every six hours for 96 hours, pushing plasma vitamin C into the low millimolar range — around 2 to 3 millimolar, some 30 to 40 times the normal saturated level of 70 to 80 micromolar, and a concentration you simply cannot reach by mouth at any dose. The trial enrolled 167 patients in total, studying those who were septic and had gone on to develop acute respiratory distress syndrome (ARDS).

And here is where I get fired up. The most frequent question about CITRIS-ALI is why mortality wasn't a primary endpoint. The answer is bureaucratic: the NIH had been burned by hundreds of failed sepsis trials and wanted a physiological outcome (the organ failure score) and biochemical outcomes (CRP and procalcitonin) instead. So the headline read as "no significant difference" on the chosen endpoint — and that result got thrown back at me, repeatedly, while I was fighting for my father. As Fowler explained, this also wasn't really a sepsis trial; patients had to wait until ARDS developed before being randomised, by which point sepsis had been doing damage for too long. In the earlier safety trial, by contrast, patients got vitamin C the second they walked in the door — which is exactly the timing that works.

Fowler was also clear-eyed about the limits of the famous Marik protocol. Subsequent trials — the ACTS trial and the VICTAS trial he participated in — using that protocol failed. His verdict: the Marik protocol is not, on its own, an effective treatment for sepsis. He noted the dose concern that haunts this whole field — the fear of oxalate crystal and renal stone formation — but in CITRIS-ALI there was no evidence of renal stones, and the FDA still demanded a fresh safety trial before he could run his COVID pneumonia study. As I said to the doctors blocking my father's treatment: the last time I looked, being dead damages your kidneys too.

Dr Paul Marik: the statistic I took into battle

Which brings me to the work that started my fight. Dr Paul Marik's small ICU study — 47 patients in the control group, 47 who received vitamin C, at relatively modest doses combined with hydrocortisone and thiamine — produced the statistic that I used when I was advocating for my father. A 40% mortality rate in the control group with sepsis and ARDS dropped to 8% in the treated group. As Levy said to me, that's a hell of a drop, and those are real people still walking around.

Now, I want to be straight with you, because you deserve honesty over hype: Marik's was a small, single-centre, before-and-after study, not a double-blind placebo-controlled trial, and as Fowler told me, later randomised trials of that exact protocol did not reproduce the result. That matters. But Levy's argument also matters: when you have something a competent clinician knows has helped, that has no defined toxicity, that isn't experimental, and that is inexpensive, the usual demand for a giant placebo-controlled trial is — in his words — a "ridiculous and foundationless argument." Those trials exist primarily to balance a drug's benefits against its dangers and to defend it in court. As Ron Hunninghake put it to me bluntly: evidence-based medicine isn't always evidence-based — it was shaped to protect pharmaceutical products. Levy's line says it best: if they're going to do a placebo-controlled trial on parachutes, he does not want to be in the control group.

My father, and the 15-day fight

I shared the full story in my conversation with Dr Joe Dituri — you can hear it in Hyperbaric Oxygen Medicine & Oxygen Toxicity with Dr Joe Dituri — but here is the short, hard version. My father suffered a massive abdominal aortic aneurysm rupture, miraculously survived the surgery thanks to a wonderful surgeon and intensivists, and then developed sepsis. From the very start I wanted intravenous vitamin C. I came with the clinical data and the research. I was told they didn't care about the clinical research — it was a legal matter, and they weren't legally protected, so they wouldn't allow it. I called the ethics committee the "unethical committee," and I meant it.

It took me 15 days of fighting the hospital boards, the ICU, every staff member, while keeping my father on life support, to win that battle. When I finally got the first infusion — and I could only get it through a legal loophole, with my own incredible GPs coming into the hospital to administer it — the very first dose was just 15 grams. It dropped his C-reactive protein in half. His white blood cell count improved massively. His kidney function improved — it went from 27 to 33 overnight — and they got him off adrenaline. One dose.

Then they stopped me. The protocol calls for an infusion every six hours; my doctors could only come every twelve, and even then I was blocked, day after day, until we were too far gone. My father died with an intravenous line still in his arm, with me beside him, when they forced me to take him off life support. I lost the battle for my dad. And that is what turned me into an activist. I don't want to be standing up and shouting. But if you have someone who is dying, who has no other options, who has given consent, and you are denied a cheap, non-toxic molecule that the world's leading researchers have spent their careers validating — something is profoundly broken.

Today I take my mum, at [age], for 30 grams of intravenous vitamin C as a prophylactic, to keep her healthy. Too little, too late for my dad. But I will keep telling this story, and keep platforming the scientists who are doing the work, until the message lands.

What I want you to take from this

Pull the five interviews together and the picture is coherent and compelling. Vitamin C is, as Fowler calls it, nature's acute care system — the rescue molecule the body reaches for whenever life is threatened. In critical illness, patients are profoundly depleted, sitting near scurvy levels (Carr). The dose and the pharmacokinetics change everything; high-dose IV is a different beast from a tablet (Hunninghake). Delivery should be strategic — IV for speed and concentration, liposomal to get it inside the cells without an energy cost, oral for everyday and chronic use (Levy). The mechanisms are real and specific: vasopressor synthesis, cell-free DNA reduction, lung barrier protection, HIF regulation, epigenetic signalling (Carr, Fowler, Vissers). And timing is decisive: give it early, give it often, and don't stop too soon (Carr, Fowler).

None of this is a substitute for emergency medicine — it sits alongside it. But the refusal to even test a critically ill patient's vitamin C level, let alone correct a profound deficiency with a molecule that has no meaningful toxicity, is the part I cannot accept. If you want to go deeper, listen to the people themselves. Every one of these interviews is linked above, and every one is worth your time.

If you take one thing from this, let it be this: vitamin C is not the little glass of orange juice. Understood properly, dosed properly, and delivered properly, it is one of the most versatile and powerful molecules in human physiology — and it is long past time the system stopped treating it like a footnote.

Listen to the interviews

• Curing the Incurable with Vitamin C with Dr Thomas Levy MD, JD

• The Power of Intravenous Vitamin C with Dr Ron Hunninghake

• Vitamin C for Sepsis & Critical Illness with Dr Anitra Carr

• IV Vitamin C for Sepsis & ARDS with Dr Alpha Berry Fowler

• Professor Margreet Vissers on Pushing The Limits

• Hyperbaric Oxygen Medicine & Oxygen Toxicity with Dr Joe Dituri (my father's story)

• Unveiling Vitamin C: Decoding Its Profound Impact on Health (Prof Margreet Vissers' work)

• Why Calcium Might Be Killing You (Dr Levy's focal scurvy theory)