The forgotten nutrient and the most important is water.
Drink, observe, clean, help undehydrate people, most important nutrient.
Calcium
Water probably
carrots
Vitamin k
yes
yes
An important nutrient would be beta carotene, which the body uses to make Vitamin A.
which nutrient supplies the body with the most calories
Carbon, Nitrogen, Oxygen
One of the most important mineral is Vitamin D but most people don't take enought to do good. It is advised to take 400-1000 mg. This helps our bones and muscles to stay strong.