In order for your body to naturally produce serotonin and melatonin you need: magnesium, calcium, iron, copper, cobalt, and zinc.
For example magnesium is what you should take to help your sleep because it will promote natural production of melatonin. Supplementing melatonin will throw your body out of balance.
Dopamine is an important hormone that is created by magnesium and B6, Iron and B6, Copper and Vitamin C. Those vitamins and minerals are grouped together because they work together.
Zinc is an important mineral that may aid in healthy brain aging and aging, also may help with ADHD in children. Be mindful if zinc is supplemented alone it will take away from copper in the body exposing you to more bacterial infections. A lack of zinc and too much copper can lead to risk of viral infection