Why are some metals important for the body?

Question

For example, iron is important for health, right? (In appropriate doses, of course) But Mercury is potentially dangerous, even at low amounts. Why is this?

Answer 1

Your body is basically a giant vehicle of chemical reactions.  You need chemical reactions to maintain certain conditions necessary for life and to gain energy to keep working.  Some metals are necessary for these chemical reactions.  Iron is a central element of hemoglobin, which carries oxygen in your blood.  Mercury is not used in any biochemical reactions native to your body and is deadly because it causes reactions that damage the nervous system.

Answer 2

Many enzymes in your body require a metal atom inside it to work. These enzymes make certain chemical reactions in your body work.are Copper, Cobalt, Zinc, Magnesium, Molybdimum, and Manganese.

The hemogloban molecule that carries oxygen in your red blood cells has an iron atom in the middle. Red blood cells in your body are dying all the time and your body makes new ones so you need iron in your diet.

Mercury in your body causes damage to nerve cells.

People who used to make felts used mercury to treat the felt.

And they got the shakes because of damage to their nerves caused by Mercury.

That's where the Mad Hatter in Alice and Wonderland came from.