Vitamin D

What it does:
Early on, most of the concern focused on bones, since vitamin D, working along with calcium, helps build and maintain them.

How much you need:
Official recommendations now call for 200 IU for children and 600 IU for people over 71, with other groups falling somewhere between.

Food sources of vitamin D:
We rely on fortified milk and breakfast cereals to get most of our dietary vitamin D. Apart from a few kinds of fish, including herring and sardines, there aren't many natural food sources, which leaves supplements and direct sunlight