Light weight lifting will help to keep the bones of the upper body strong. Boron is found in apples, pears, grapes and other fruit, as well as in legumes, nuts and honey. Make sure that you are getting enough of the trace mineral manganese. You'll find manganese in pineapples, nuts, spinach, beans and whole wheat. Your skin can also make vitamin D when exposed to the sun.
Supplements are helpful, but too much vitamin D is dangerous.