Minerals

"Minerals" are elements found in minerals that are a component of body molecules or that catalyze or participate in the synthesis of body molecules or metabolic reactions.   The 21 elements essential to human life, either as macronutrients (relatively large amounts, measured in milligrams) or micronutrients (small amounts, measured in micrograms), are as follows:

calcium
carbon
chlorine
chromium
cobalt
copper
fluorine
hydrogen
iodine
iron
magnesium
manganese
molybdenum
nitrogen
oxygen
phosphorus
potassium
selenium
sodium
sulfur
zinc

Note 1: Excluded from nutrition lists are carbon, hydrogen, nitrogen, and oxygen, which are ingested as carbohydrates, fats, and proteins in food, so they are not considered "essential minerals".   Oxygen is, of course, also inhaled as a gas from air.   Salt provides sodium and chlorine.

Note 2: Since animal life depends on plant life, and boron and nickel are essential to plant life, they are indirectly essential to humans.   Elements essential to plant life are found here.