Why are minerals needed?

Answer 1

Minerals are needed because like Vitamins they help us to fight against diseases

and they are for the growth of teeth, eyes and bones. They also

maintain a normal heartbeat. So you should eat food items rich in minerals.

And this is the reason that "Why are vitamins needed."
Your Body requires minerals to stay healthy and function. Among MANY others, just remember that your bones are mainly a mineral- calcium- and without bones you would basically be a puddle of meat on the floor. It also helps to keep your bones and teeth healthy.