The human body contains enough iron to make a small nail.
Why it is true
Most of the bodys iron is in haemoglobin, the protein in red blood cells that carries oxygen. In total, an adult has between 3 and 4 grams of iron. That amount is enough to make a nail about 5 centimetres long. Iron is obtained through food, such as meat, beans and spinach.
Source: Smithsonian
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