Osteoporosis literally means "porous bone." It is a disease in which bone loses density and strength, so it breaks more easily, often from a minor fall or with no injury at all. It usually causes no symptoms until a bone breaks, which is why it is worth understanding your risk well before then.
How common is osteoporosis?
Very. In 2010, an estimated 10.2 million Americans aged 50 and over had osteoporosis, and another 43.3 million had low bone mass, which raises the risk of developing it. Worldwide, there were an estimated 9 million osteoporotic fractures in 2000, about 1.6 million of them at the hip.
Women are hit hardest. About half of all women over 50 will break a hip, wrist or spinal bone during their lifetime, and spine fractures are the most common.
What happens to bones in osteoporosis?
Bone is living tissue. Throughout your life your body breaks down old bone and builds new bone, a process called remodeling. As long as the two stay in balance, bones stay strong. Osteoporosis develops when more old bone is reabsorbed than new bone is created, so bones become thinner and more fragile. In young adulthood you build bone faster than you lose it; later in life, the balance tips the other way.
The role of calcium and vitamin D
Your body needs calcium and phosphate to build bone, and vitamin D's main job is helping your intestine absorb calcium. If you do not get enough calcium, or not enough vitamin D to absorb it, your body draws calcium from your bones. Our guide to what vitamin D does covers this in more detail.
Who is at risk of osteoporosis?
Some risk factors you cannot change: being older, being female, a family history of osteoporosis and some ethnic backgrounds all raise the odds. In general, white, older women are the most likely to have bone loss. Other risk factors listed by MedlinePlus include:
- not getting enough calcium and vitamin D, or not absorbing them, for example after gastric bypass surgery
- the drop in estrogen at menopause, and lower testosterone in men as they age
- long periods without menstrual periods
- conditions that cause inflammation, such as Crohn's disease or rheumatoid arthritis
- certain medicines, including some seizure medicines, hormone treatments for prostate or breast cancer, and steroids taken for more than three months
- smoking, heavy drinking, low body weight and eating disorders such as anorexia
- long periods confined to bed
Estrogen helps protect bone, which is why bone loss speeds up after menopause and why missed periods during the reproductive years, from low body weight, over-training or other causes, are worth discussing with a doctor.
What are the symptoms of osteoporosis?
In the early stages, there are no symptoms at all, and many people learn they have osteoporosis only when they break a bone. Spinal fractures can cause back pain, a gradual loss of height of as much as 6 inches, and a stooped posture.
How is osteoporosis diagnosed?
A DEXA scan, a low-dose x-ray, measures bone mineral density, usually at the spine and hip. The US Preventive Services Task Force recommends this screening at least once for women 65 and older, and for some younger women at higher risk. Your doctor can tell you whether a bone density test is right for you.
Can you lower your risk of osteoporosis?
You cannot change your age or your genes, but you can influence a lot. MedlinePlus recommends getting enough calcium and vitamin D, regular exercise, not smoking and not drinking large amounts of alcohol. Most adults need 1,000 mg of calcium a day, rising to 1,200 mg for women over 50 and men over 70, and 600 IU of vitamin D a day, or 800 IU after 70. Our article on natural ways to reduce your risk of osteoporosis goes through each habit.
If you do not get enough vitamin D from sun and food, a supplement can help you meet your needs for normal calcium absorption; our Sol Food tablets provide 2,000 IU of plant-based vitamin D3, and our guide to how much vitamin D you need explains the numbers. If you have been diagnosed with osteoporosis or low bone density, talk to your doctor: there are effective medicines, and supplements are not a substitute for them.
