No matter how old you are, you should protect your bones by eating well, exercising, and avoiding cigarettes (see Timeless Advice, below). But as your body, hormones, and lifestyle change, there are certain things you should do to make sure your skeleton gets the protection and help it needs.

On the following pages is decade-by-decade information on what to do to ensure that the 206 bones in your body stay strong and supportive in every decade of your life.

Timeless Advice

Throughout your life, be sure to:

Stick with a bone-friendly diet. Eat plenty of fruits, vegetables, and low-fat dairy products. Women should consume 1,000 milligrams of calcium and 400 to 800 I.U. (international units) of vitamin D a day. After menopause, they should consume more.

Keep moving. Exercise may have a greater effect on bone strength than calcium consumption, according to recent research. The more impact, the better: Running, lifting weights, and jumping rope are all excellent bone builders.

Quit smoking. Compared with nonsmokers, women who smoke have lower estrogen levels and typically reach menopause earlier, both of which lead to lower bone density.

Watch the salt. A high-sodium diet (more than 2,400 milligrams a day) is associated with excess calcium excretion.

Be careful with alcohol. Moderate drinking (one alcoholic beverage a day for women) may be good for the bones because it increases estrogen levels; larger amounts could be harmful.

Tip: Splurge on lattes. A grande skim latte from Starbucks has 450 milligrams of calcium — 45 percent of your daily requirement.

Know Your Diagnosis

There are two medical terms for low bone density.

Osteopenia means you have low bone mass that isn’t low enough to be osteoporosis. About 20 percent of premenopausal women have osteopenia.

Osteoporosis is much more serious and means your bones have lost so much density that they’re porous and susceptible to fractures, especially in the hips, spine, and wrists. While osteoporosis is most common after menopause, it can occur at any age.