A complete analysis on a 150 pound person would show that 90 pounds are water and about 30 pounds fat. The other 30 pounds are mostly protein, carbohydrate, and the major minerals of your bones - calcium and phosphorus. Vitamins, other minerals, and incidental extras constitute a fraction of a pound.
Water is the forgotten nutrient.
It's the fluid part of the blood and the interior spaces in the cells. Water transports materials to and from cells and provides the warm, nutrient-rich bath in which cells thrive. It also conducts hormonal messages from place to place. When fuel nutrients break down to release energy, they break down to water and other simple compounds. Since you lose water from your body daily, you must replace it daily.