By Mayo Clinic Staff

Bones do a lot for your body. They provide structure, protect organs, anchor muscles and store calcium. While it's important to build strong, healthy bones during your childhood and teen years, you can take steps to protect bone health when you're an adult too.

Bones change all the time. The body constantly makes new bone and breaks down old bone. This process is called remodeling. When you're young, new bone is made faster than old bone is broken down. So the amount of bone mass you have goes up. Most people reach peak bone mass around age 30. After that, bone remodeling continues. But you lose slightly more bone mass than you gain.

Osteoporosis is a condition that causes bones to become weak and easily broken. How likely you are to develop osteoporosis depends on how much bone mass you have by the time you're 30 and how quickly you lose it after that. The higher your peak bone mass, the more bone you have built up. The more bone you have built up, the less likely you are to develop osteoporosis as you get older.

Lots of things can affect bone health. For example:

• The amount of calcium in your diet. A diet low in calcium may lead to low bone density, early bone loss and easily broken bones.
• Physical activity. Exercise makes bones stronger. People who aren't physically active have a higher risk of osteoporosis than people who exercise regularly.
• Tobacco and alcohol use. Using tobacco, especially smoking and vaping, can weaken bones and raise the risk of osteoporosis. Regularly having more than one alcoholic drink a day for women or two alcoholic drinks a day for men also may raise the risk of osteoporosis.
• Sex. Females are at higher risk of osteoporosis than males. That's because females have less bone tissue than males do.
• Size and age. People who have a body mass index of 19 or less or who have a small body frame are at higher risk of osteoporosis. That's because they typically have less bone mass to draw from as they age. Bones also become thinner and weaker as people get older.
• Race and family history. People of white or Asian descent are at a higher risk of osteoporosis than other people. People who have a parent with osteoporosis are at higher risk too. A family history of broken bones also raises the risk.
• Hormone levels. Hormones affect bones. Too much thyroid hormone can cause bone loss. And due to dropping estrogen levels, there's usually a lot of bone loss around the time of menopause. Before menopause, people who don't have their periods for a long time — a condition called amenorrhea — have a higher risk of osteoporosis. Low testosterone levels can cause a loss of bone mass.

Taking some medicines for a long time may damage bones. Examples include:

• Hormone medicines used to treat breast cancer and prostate cancer.
• Medicines used to prevent seizures.
• Medicines used to treat thyroid diseases.
• Glucocorticoid steroids.
• Adrenocorticotropic hormone.
• Selective serotonin reuptake inhibitors.
• Thiazolidinediones.
• Proton pump inhibitors.

Some medical conditions also can affect bone health. For example, having an eating disorder such as anorexia raises the risk of osteoporosis because not eating enough and being underweight weakens bones. Medical conditions such as thyroid diseases, inflammatory bowel disease, rheumatoid arthritis and Cushing syndrome can raise the risk of bone loss.

The following steps may help prevent or slow bone loss:

• Include plenty of calcium in your diet. For adults ages 19 to 50 and men ages 51 to 70, the Recommended Dietary Allowance (RDA) is 1,000 milligrams (mg) of calcium a day. The recommendation goes to 1,200 mg a day for women age 51 and older and for men age 71 and older.

  Good sources of calcium include dairy products, turnip greens, salmon and canned salmon with bones, sardines, tuna, and soy products, such as tofu. If it's hard to get enough calcium from your diet, ask your healthcare professional about taking a calcium supplement.

• Get enough vitamin D. Vitamin D helps the body absorb calcium. For adults ages 19 to 70, the RDA of vitamin D is 600 international units (IUs) a day. The recommendation goes to 800 IUs a day for adults age 71 and older.

  Good sources of vitamin D include oily fish, such as salmon, trout, tuna and mackerel. Some foods also have vitamin D added to them, such as milk, cereals and orange juice. Sunlight helps the body make vitamin D too. If you're worried about getting enough vitamin D, ask your healthcare professional about taking a supplement.

• Stay active. Weight-bearing exercises can help you build strong bones and slow bone loss. Examples include brisk walking, jogging, dancing, climbing stairs, and playing soccer, tennis and pickleball.
• Don't use tobacco or drink too much. If you'd like help to stop using tobacco, talk to your healthcare professional. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
• Ask about medicines. If you have to take any medicine for a long time, ask your healthcare professional if that might affect your bones. If so, talk about steps you can take to keep your bones healthy.

If you're worried about bone health or you have risk factors for osteoporosis, talk to your healthcare professional. Also talk to your healthcare professional about bone health if you break a bone when you're older than 50. You may need a bone density test. The results of that test show your level of bone density. The test results also can help your care team check your rate of bone loss and other measures of bone health. Using that information along with your risk factors, your healthcare professional can decide if medicine to help slow bone loss may be a good choice for you.

A number of factors can affect bone health. For example:

• The amount of calcium in your diet. A diet low in calcium contributes to diminished bone density, early bone loss and an increased risk of fractures.
• Physical activity. People who are physically inactive have a higher risk of osteoporosis than do their more-active counterparts.
• Tobacco and alcohol use. Research suggests that tobacco use contributes to weak bones. Similarly, regularly having more than one alcoholic drink a day for women or two alcoholic drinks a day for men may increase the risk of osteoporosis.
• Sex. You're at greater risk of osteoporosis if you're a woman, because women have less bone tissue than do men.
• Size. You're at risk if you are extremely thin (with a body mass index of 19 or less) or have a small body frame because you might have less bone mass to draw from as you age.
• Age. Your bones become thinner and weaker as you age.
• Race and family history. You're at greatest risk of osteoporosis if you're white or of Asian descent. In addition, having a parent or sibling who has osteoporosis puts you at greater risk — especially if you also have a family history of fractures.
• Hormone levels. Too much thyroid hormone can cause bone loss. In women, bone loss increases dramatically at menopause due to dropping estrogen levels. Prolonged absence of menstruation (amenorrhea) before menopause also increases the risk of osteoporosis. In men, low testosterone levels can cause a loss of bone mass.
• Eating disorders and other conditions. Severely restricting food intake and being underweight weakens bone in both men and women. In addition, weight-loss surgery and conditions such as celiac disease can affect your body's ability to absorb calcium.
• Certain medications. Long-term use of corticosteroid medications, such as prednisone, cortisone, prednisolone and dexamethasone, is damaging to bone. Other drugs that might increase the risk of osteoporosis include aromatase inhibitors to treat breast cancer, selective serotonin reuptake inhibitors, methotrexate, some anti-seizure medications, such as phenytoin (Dilantin) and phenobarbital, and proton pump inhibitors.

If you're concerned about your bone health or your risk factors for osteoporosis, including a recent bone fracture, consult your doctor. He or she might recommend a bone density test. The results will help your doctor gauge your bone density and determine your rate of bone loss. By evaluating this information and your risk factors, your doctor can assess whether you might be a candidate for medication to help slow bone loss.