Women may lose 5 percent of their bone mass each year in that period.

And nearly another 34 million are thought to have low bone mass.

Astronauts lose an average of more than 1% bone mass per month spent in space.

But everyone with low bone mass is at higher risk for getting it.

You build about 90% of your bone mass by the time you're 18 to 20.

After age 30, men and women naturally begin to lose bone mass.

Women are usually affected at an earlier age than men, because they start out with lower bone mass.

The years from childhood until age 30 are prime time for building bone mass.

All those little fish bones have just what you need to build bone mass in your own body.

"We should be doing the same routine assessment with bone mass."