Vitamin C

No trial has ever compared retinol with vitamin C for aging skin. Here is what each is actually shown to do, and where the evidence runs out.

Does vitamin C tighten saggy skin? No. The one trial to measure elasticity found a small dip, not a gain. Sagging is an elastin problem, not a diet one.

Vitamin C builds the collagen in artery walls, but trials found no drop in cardiovascular events. What it does, what it can't, and where evidence stops.

What has 6000 times more vitamin C? Nothing does — the figure is astaxanthin's antioxidant potency, not vitamin C content, and it traces to one 2007 study.

What to pair with vitamin C? Only iron has strong evidence, and only at a meal. What the research supports, what it doesn't, and the pairing nobody sells.

What does vitamin C do for you? It builds collagen, stocks immune cells, unlocks plant iron and aids 18 enzymes. What the evidence shows, and what it doesn't. 

Sustained 1,000mg vitamin C doses blunted mitochondrial gains in trials. What athletes should know about oxidative stress, recovery and race-week timing.

Vitamin C for colds will not stop you catching one. The trials do show a 26% cut in severe symptoms, plus one group where prevention genuinely works.

Your immune cells hold 50-100x more vitamin C than your blood. What that means for the vitamin C immune system link, and what supplementing really does.