Here’s the recipe to make an average-sized human: 15 kg of carbon, 4 kg of nitrogen, 1 kg of calcium, half a kg of phosphorus, 200 g of sodium, 150 g of potassium, 150 g of chlorine, a few grams of about 15 other elements (some exotic, like selenium, lithium, and vanadium in trace amounts), and four 10-liter buckets of water.
The 40 liters of water can be made by combining 5 kg of hydrogen and 35 kg of oxygen. Commercial cost? Just a few euros.
The hydrogen and a pinch of lithium come from the Big Bang, about 15 billion years ago. The other ingredients are more recent; they required billions of years of cosmic evolution, with stars being born, shining, dying, and reforming in nebulae from stellar collapse.
The 15 kg of carbon was formed in a star’s final stages by combining three helium atoms. The 35 kg of oxygen came from the fusion of carbon and helium in extremely hot stars. Iron is the ash of spent stars, and calcium, phosphorus, sulfur, chlorine, sodium, and nitrogen also come from these stellar forges.
Traces of even heavier elements reach us from supernovae. In short, we are born from the stars.