The elements of the periodic table, and where they originate, are detailed in this image above. The vast majority of the human body, including the majority of our oxygen, carbon, nitrogen, phosphorous, calcium, and iron, all owe their primary origin to massive stars that have gone supernova.
The hydrogen in your body, present in every molecule of water, came from the Big Bang. There are no other appreciable sources of hydrogen in the universe. The carbon in your body was made by nuclear fusion in the interior of stars, as was the oxygen.
Most of the elements of our bodies were formed in stars over the course of billions of years and multiple star lifetimes. However, it's also possible that some of our hydrogen (which makes up roughly 9.5% of our bodies) and lithium, which our body contains in very tiny trace amounts, originated