Everything from the fibres in the Shroud of Turin to Otzi the Iceman has had their birthday determined the carbon-14 way. There's plenty of hydrogen, oxygen and nitrogen in living things too, but carbon's got something none of them do — a radioactive isotope that can take thousands of years to decay.
(You can read up on radioactivity and isotopes here).
But don't panic — of the 800,000,000,000,000,000,000,000,000 carbon atoms in every one of us, about 800,000,000,000,000 are carbon-14, so we've got a few to spare.
Not only that, we top up our carbon-14 levels every time we eat.
All radioactive atoms eventually decay into something more stable, and carbon-14 decays into nitrogen.For a rare event it happens pretty damn often — one million carbon-14 atoms in your body decay into nitrogen every minute!