A 24-year-old woman with a large appetite for salt consumes about 25g of salt each day. What is the approximate amount of salt (in grams) that is excreted each day by her kidneys?
High-Yield Explanation
About 95% of the salt (sodium chloride) that is consumed by a person is excreted by the kidneys; the remaining 5% is excreted in the sweat and feces. The total intake of salt (amount of salt consumed each day) must equal the total output of salt (amount of salt excreted each day) under normal steady conditions, ie, salt intake = salt output. Therefore, it is clear that 25g of salt must be excreted by the kidneys each day when 25g of salt is consumed each day. 95% of 25 is around 23g.