Substance which is finally excreted in the urine

A vitamin which is generally excreted in human urine is OR Earliest known vitamin is

The preservative which is ultimately excreted in urine as hippuric acid is .

The preservative which is ultimately excreted in urine as hippuric acid is

The vitamin(s), which is/are generally excreted in urine, is/are

The amount of urea which is excreted out in the urine per day of an adult human is

The amount of urea which is excreted out in the urine per day of an adult human is

Which one among the following substances is never excreted out through urine normal circumstances in any healthy individual?