If you eat zero carbohydrate, do you still need vitamin C, and does everyone need to go that far?

Anthony ChaffeePhysician · strict carnivore, evolutionary framing

No supplement is needed once carbohydrate is gone, and for people who remain symptomatic the answer is to narrow further, not to reintroduce.

What it rests onHe argues carbohydrate competes with vitamin C for uptake in the gut (he names the GLUT4 receptor), so the requirement falls when carbohydrate is removed, and that meat supplies already-hydrolysed proline and lysine so the collagen reaction that fails in scurvy does not need vitamin C to catalyse it. He supports it with the observation that carnivore eaters do not present with scurvy and with a historical reading of British naval scurvy. This is his own account of the mechanism, receptor and all.

Eric Charles WestmanMD, MHS · internist and Associate Professor of Medicine, Duke University

Vitamin C requirement is plausibly conditional on how you eat, and that is a reason to test the question rather than to assume everyone belongs at the strictest end.

What it rests onIn the same interview he raises vitamin C as his own challenge, answers it by citing Steve Phinney that 'We handle vitamin C differently with different ways of eating', and says in his own voice 'At the same time, I'm not totally convinced that everyone needs a carnivore diet'. Separately, on his own site, he writes 'Not everyone needs to be on strict keto, which might be a surprise to those who are in the keto echo chamber', and frames the task as finding your own carbohydrate threshold. He is not arguing that carnivore is unsafe: his site publishes carnivore guides under his review.