Vitamin D and Osteoporosis

Osteoporosis

Osteoporosis is a condition where you lose too much bone or don’t make enough bone to replace the bone that you normally lose. If you lose too much bone, your bones become less dense and are more likely to break. People with osteoporosis have low bone density.

If you have osteoporosis, even events in normal life, such as sneezing or bumping into an object, can cause a bone to break.

There are many factors that may play a role in your risk of developing osteoporosis. Some you can control, like not smoking and getting enough calcium, and some you can’t control, like being a female and growing older.

Researchers are still trying to find out the exact role vitamin D plays in the development of osteoporosis. Since you need vitamin D to help absorb calcium, doctors and scientists generally believe you need to get enough calcium and vitamin D throughout life to develop healthy bones and reduce your risk of developing osteoporosis.

If you’re at high risk of developing osteoporosis, some studies show vitamin D can slow bone loss, although research is mixed, with some studies showing no effect.

If you have osteoporosis, vitamin D can’t help you improve your bone density and cure your osteoporosis. However, vitamin D may help slow further bone loss, although more research is needed.

Vitamin D may be helpful in managing your osteoporosis in other ways, too. The main concern in having osteoporosis is breaking a bone. There is some evidence that vitamin D can help prevent a broken bone indirectly by preventing you from falling and breaking a bone.

If you have osteoporosis or at high risk and want to take a vitamin D supplement, it’s unlikely to harm you or make your symptoms worse. However, you may not see any improvement in your symptoms either. You should not take vitamin D in the place of other medications for your condition. Talk to your doctor about taking vitamin D or any other supplement.

What is osteoporosis?

Osteoporosis is a condition that affects your bones. It occurs when you lose too much bone or don’t make enough new bone to replace the bone that you normally lose. When this happens, your bones become less dense. People with osteoporosis have low bone density. People that don’t have osteoporosis have normal bone density. There is also a condition called osteopenia, where your bone density is lower than normal, but not quite low enough to be considered osteoporosis.

People with osteoporosis are more likely to break their bones. When people with osteoporosis break a bone it is usually in the wrists, hips, or spine, but any bone in your body can break.¹

How common is osteoporosis?

Roughly 9 million people in the United States have osteoporosis. Most people with osteoporosis are diagnosed after the age of 50.

The main concern in osteoporosis is you have a higher risk of breaking a bone. Your chance of breaking a bone in your lifetime if you have osteoporosis is 1 in 2 for women and 1 in 4 for men.¹ Your risk of breaking a bone is greater if you:²

• are female
• are postmenopausal
• are over the age of 50
• have a low body weight
• currently smoke
• drink three or more alcoholic drinks per day
• have a low calcium and vitamin D intake
• broke a bone in the past

What are the symptoms of osteoporosis?

For many people the first sign that they have osteoporosis is when they break a bone. Because you cannot feel your bones becoming less dense, many people have osteoporosis without knowing it. If you lose enough bone, even normal events in your daily life, such as sneezing or bumping into an object, could cause a bone to break.

Bones can break in your spine without causing any pain. This can cause you to become shorter or develop a curve in your back.¹ If you notice that you are losing height or developing a curve in your back, it’s important that you talk to your doctor.

What causes osteoporosis?

Scientists and doctors don’t know for sure what causes osteoporosis. You can control some of the things that increase your risk of developing osteoporosis, like not smoking and getting enough calcium, while some of the others you can’t, like your age and sex.

Bones are made from living tissue. Your body is constantly making new bone and getting rid of old bone. This process of replacing old bone with new bone is called “bone turnover.”

Around age 30, this process reverses and you slowly begin to lose more bone than you produce, so your bones become less dense with time.

During childhood and until around age 30, you produce more bone than you get rid of. This means your bones are slowly growing more dense and strong during the first 30 years of your life. Around age 30, this process reverses and you slowly begin to lose more bone than you produce, so your bones become less dense with time. This process of losing bone speeds up in most people after age 50.

These are some of the things you can control to decrease your risk of developing osteoporosis:¹

• Ensure an adequate intake of calcium and vitamin D. Calcium makes bones dense and strong, and your body requires vitamin D to absorb calcium.
• Maintain an active lifestyle. Exercise can help you build new bone and improve balance, strength, and flexibility so you are less likely to fall and break a bone.
• Restrict your alcohol intake. People who regularly drink more than three alcoholic drinks per day tend to have less dense bones than more moderate drinkers.
• Don’t smoke. Smokers tend to have less dense bones than non-smokers.

These are some of the things you can’t control that increase your risk of developing osteoporosis:¹

• Being female. Women are more likely than men to develop osteoporosis.
• Menopause. After menopause, estrogen levels are lower, which makes your bones less dense.
• Being over age 50. After age 30, you slowly begin to lose more bone than you make. This process speeds up after around the age of 50.
• Being small or thin. Having smaller bones means you have less bone to lose than people with larger frames.
• Family history. If you have family members with osteoporosis, you may be more likely to develop this condition.

Other diseases and medications can cause bone loss, increasing your risk of osteoporosis.¹ Talk to your doctor to determine if you are at risk of developing osteoporosis.

What is the general link between osteoporosis and vitamin D?

Vitamin D plays an important role in developing healthy bones.

Your bones contain many different minerals, of which calcium is the most important.³ Ninety-nine percent of the calcium in your body is found in your teeth and bones.¹ Calcium makes bones dense and strong. Having more calcium in your bones makes them denser so they are less likely to break.³

Your body requires vitamin D to absorb the calcium in your diet.¹ When you don’t get enough vitamin D, you can’t absorb the calcium you need for your bones. However, doctors are still figuring out how much vitamin D you need to properly absorb calcium.

Researchers have also discovered that people with osteoporosis tend to have lower levels of vitamin D in their blood than people who do not have osteoporosis. They do not know if this is because having less vitamin D in their blood makes them more likely to develop osteoporosis or if having osteoporosis causes their bodies to have lower levels of vitamin D for some reason.

The other link between vitamin D and osteoporosis has to do with breaking a bone. Most people get vitamin D from exposing their bare skin to sunlight. There is less sun available to make vitamin D during the winter months, so people usually have lower levels of vitamin D in their blood during the winter than the summer. More people break their bones during the winter in both the Northern and Southern hemispheres than other times of the year, and some researchers believe this is because people have lower levels of vitamin D in their bodies during this time.⁴

Other research has found that people who have higher levels of vitamin D in their blood have stronger muscles and better leg function than people with lower levels of vitamin D.⁵ This may mean they are less likely to have an accident and fall and break a bone than people with lower levels of vitamin D because they are stronger and have better balance.

What does research say about the role of vitamin D in preventing osteoporosis?

Preventing osteoporosis by building more bone when you’re younger (before the age of 30)

A 2013 Research Study from Lebanon⁶ compared teenage girls and boys who took vitamin D supplements with others who took a placebo. The main result was:

• The girls who took vitamin D developed denser bones and gained more bone mass compared to girls who took the placebo. Taking vitamin D had no effect on the bone density of the boys in the study.

Many researchers believe that if you make more bone while you are young, you will be less likely to develop osteoporosis when you are older. However, since the number of people in the study was small and it lasted for only a short time, researchers can’t say for sure whether taking vitamin D supplements will lead to better bone density over time, or if getting enough vitamin D when you are younger will help prevent osteoporosis later in life.

Preventing osteoporosis by slowing bone loss when you’re older (over the age of 30)

When you’re older, if you can slow down the rate at which you lose bone then your bones are more likely to remain strong and dense for a longer period of time. This means you will be less likely to develop osteoporosis and therefore less likely to break a bone. Some research shows that women who take vitamin D supplements lose less bone than women who do not take vitamin D supplements.^7,8

A 2013 research study from the United Kingdom⁸ looked at whether or not taking a vitamin D supplement made people’s bones more dense and strong. The main result was:

• Women who took a vitamin D supplement had more dense bones at the end of the study than women who didn’t take vitamin D.

This study compared healthy women who took vitamin D supplements with women who did not. The researchers found that healthy women who took more vitamin D than what the government recommends lost less bone as they got older than women who were taking less vitamin D. The women who took vitamin D had denser bones, which means their bones were less likely to break.

A 2011 research study from Norway⁹ looked at whether or not taking a vitamin D supplement made people’s bones more dense and strong. The main result was:

• Women who took vitamin D supplements did not have more dense bones at the end of the study.

This study gave vitamin D supplements to women with both osteopenia and osteoporosis. Some women took an amount of vitamin D equal to what the government recommends and some women took a much larger amount. There were no changes in the bones of any of the women.

Since researchers did not follow the women in either study for a long period of time, they can’t say for sure whether vitamin D supplementation can prevent osteoporosis or not.

Most doctors and scientists think getting enough calcium throughout your life is important to prevent osteoporosis by helping keep your bones strong and dense. It is clear that you need vitamin D to help absorb calcium, though scientists aren’t exactly sure how much vitamin D you need to fully absorb calcium.

This means it is important to get enough calcium as well as vitamin D, not just one or the other by itself. See the Office of Dietary Supplements website for more information on calcium.

What does research say about vitamin D being able to treat osteoporosis?

Once you have osteoporosis, vitamin D can’t help build bone density back up. Doctors and scientists are still trying to discover if vitamin D can help slow even more bone loss once you have osteoporosis. As mentioned above, research so far is mixed.

However, if you have osteoporosis, most doctors and scientists think getting enough calcium is important to prevent you from losing even more bone. It is clear that you need vitamin D to help absorb calcium, though scientists aren’t exactly sure how much vitamin D you need to fully absorb calcium.

This means that getting enough calcium and enough vitamin D is important, not just getting vitamin D by itself or calcium by itself. See the Office of Dietary Supplements website for more information on calcium.

What does research say about vitamin D being able to help manage osteoporosis?

If you already have osteoporosis, the main goal in managing your condition is to avoid breaking a bone. There is a lot of research studying the role of vitamin D in preventing broken bones in people with osteoporosis or osteopenia, but the results are mixed.

For some people, taking vitamin D supplements appears to reduce their risk of breaking a bone, while for other people there is no clear benefit. Some research shows that the people most likely to benefit from taking vitamin D supplements to prevent broken bones due to osteoporosis are frail, older people living in institutions, such as nursing homes and assisted living communities.^2,4,5

Because there are differences in the way the research studies were designed and carried out, this makes them difficult to compare. These include differences in:⁴

• the form of vitamin D people take, for example tablets or injections.
• the amount of vitamin D people take.
• how often people take the vitamin D, for example every day or once a week.
• the people taking part in the research, for example different age groups.
• how researchers measured if the people took their supplements or not.
• whether people took calcium along with their vitamin D or not.

Also, because many of the people in these studies took calcium supplements along with the vitamin D, it is difficult to know exactly what effect the vitamin D was having. Some researchers believe that to help treat osteoporosis and prevent people from breaking a bone, it may be necessary to take both calcium supplements and vitamin D supplements together.^2,4,5

Here is what some more recent research says on preventing a bone from breaking:

A 2012 research study from the United States¹⁰ looked at whether or not giving vitamin D supplements to people would make their bones denser and stronger to prevent them from breaking a bone. Many of the people already had osteoporosis but some did not. The main results were:

• People older than 65 who took vitamin D supplements were less likely to break a bone than those who didn’t.
• Vitamin D supplements helped prevent people from breaking a bone whether they lived in an institution or not.

This study compared people who took different amounts of vitamin D supplements and whether they broke a bone later or not. The people in the study who were taking an amount of vitamin D greater than or equal to what the government recommends broke a bone less often than people who were taking smaller amounts of vitamin D. Many people in the study were also taking calcium, so it’s difficult to know exactly what effect the vitamin D was having.

A 2009 research study from Denmark¹¹ looked at a large group of people to see if taking vitamin D supplements or vitamin D with calcium reduced their chance of breaking a bone. Many of the people already had osteoporosis, but some did not. The main results were:

• Taking vitamin D supplements alone didn’t reduce their chance of breaking a bone.
• People who took vitamin D and calcium supplements together reduced their chance of breaking a bone.

This study found that people had to take calcium and vitamin D supplements together to avoid breaking a bone. Taking only vitamin D supplements didn’t prevent them from breaking a bone.

Key points from all the research

• People diagnosed with osteoporosis tend to have lower blood levels of vitamin D than other healthy people of their age.⁴
• You need vitamin D to fully absorb calcium. It’s not clear how much vitamin D you need to fully absorb calcium.
• Because vitamin D and calcium work together to make bones strong, it’s difficult to know what effect vitamin D has by itself on bones.
• There is some evidence that getting enough vitamin D will help bones stay more dense compared to not getting enough vitamin D, though research is mixed. The denser you can keep your bones, the less likely you are to get osteoporosis or break a bone later in life.
• There is some evidence that vitamin D prevents fractures in amounts equal to or more than what the government recommends.¹⁰ If you have osteoporosis, preventing fractures is the main goal in managing your condition.
• The people most likely to benefit from taking vitamin D supplements to prevent a broken bone are frail, older people, living in institutions.^2,4,5
• Some researchers believe that to help treat and manage osteoporosis and prevent broken bones, it may be necessary to take both calcium and vitamin D supplements together.^2,4,5

What does this mean for me?

Research does show a link between vitamin D and bone health, but it’s not clear what exact role vitamin D plays in the development, treatment and management of osteoporosis.

Consuming enough calcium is important for healthy bones, and vitamin D is necessary to absorb this calcium. However, it isn’t known the exact amount of vitamin D you need to fully absorb calcium.

If you have osteoporosis or are at high risk for it and want to take vitamin D, it’s unlikely to make your symptoms worse or cause you any harm if you take less than 10,000 IU/day.

If you’re at high risk of developing osteoporosis, there is some evidence that vitamin D might slow bone loss, but researchers can’t say for sure at this time.

There is some evidence that vitamin D can help manage your osteoporosis by helping to prevent you from falling and breaking a bone.

If you have osteoporosis, it’s important that you talk to your doctor about taking vitamin D or any other supplements. You should not take vitamin D in the place of other medications for your condition.

References

1. What is Osteoporosis? National Osteoporosis Foundation. Accessed on August 1^st, 2013 at http://www.nof.org/articles/7.
2. Levis S, Theodore G. Summary of AHRQ’s comparative effectiveness review of treatment to prevent fractures in men and women with low bone density or osteoporosis: update of the 2007 report. J Manag Care Pharm. 2012;18(4 Suppl B):S1-15.
3. Fact sheet: Preventing osteoporosis. PubMed Health. Accessed on August 1^st, 2013 at http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004996/.
4. Avenell A, Gillespie WJ, Gillespie LD, O’connell D. Vitamin D and vitamin D analogues for preventing fractures associated with involutional and post-menopausal osteoporosis. Cochrane Database Syst Rev. 2009;(2):CD000227.
5. Bischoff-ferrari HA. Which vitamin D oral supplement is best for postmenopausal women?. Curr Osteoporos Rep. 2012;10(4):251-7.
6. Al-Shaar L, Nabulsi M, Maalouf J, El-Rassi R, Vieth R, Beck TJ, El-Hajj Fuleihan G. Effect of vitamin D replacement on hip structural geometry in adolescents: A randomized controlled trial. Bone, 2013 Oct;56(2):296-303. doi: 10.1016/j.bone.2013.06.020.
7. Ooms ME, Roos JC, Bezemer PD, Van der vijgh WJ, Bouter LM, Lips P. Prevention of bone loss by vitamin D supplementation in elderly women: a randomized double-blind trial. J Clin Endocrinol Metab. 1995;80(4):1052-8.
8. Macdonald HM, Wood AD, Aucott LS, et al. Hip bone loss is attenuated with 1000 IU but not 400 IU daily vitamin D3: a 1 year double-blind RCT in postmenopausal women. J Bone Miner Res. 2013;
9. Grimnes G, Joakimsen R, Figenschau Y, Torjesen PA, Almås B, Jorde R. The effect of high-dose vitamin D on bone mineral density and bone turnover markers in postmenopausal women with low bone mass– a randomized controlled 1-year trial. Osteoporos Int. 2012;23(1):201-11.
10. Bischoff-ferrari HA, Willett WC, Orav EJ, et al. A pooled analysis of vitamin D dose requirements for fracture prevention. N Engl J Med. 2012;367(1):40-9.
11. Patient level pooled analysis of 68 500 patients from seven major vitamin D fracture trials in US and Europe. BMJ. 2010;340:b5463.