What are mineral salts?
Mineral salts matter as a nutritional component for maintaining the life processes of living things.
Two groups
Macro elements
Elements needed in a relatively larger percentage.
Examples: calcium, phosphorus
Micro elements
Elements needed only in small amounts.
Examples: iodine, copper
How much in the human body?
7% of human body weight is mineral salts.
About three quarters of that is calcium and phosphorus.
The rest includes potassium, iron, magnesium, copper and iodine.
Small amount, large effect
The key point
These elements are needed only in very small amounts. But when even that small amount is not obtained, plants and animals show various deficiency symptoms.
So "needed in small amounts" must not be read as "less important".
The next two pages cover what these elements do in humans and in plants, and what appears when they run short.