Bone health and kidney disease

Who is at risk for bone problems with kidney disease?

Anyone with CKD can develop bone and mineral health problems, but the risk is higher in later stages of CKD.

You may be at higher risk if you:

• Have kidney failure, also called end-stage renal disease (ESRD) or end-stage kidney disease (ESKD)
• Are on dialysis
• Have high phosphorus
• Have high or low parathyroid hormone (PTH)
• Have low vitamin D
• Have had a broken bone
• Take medicines that can affect bone health, such as steroids or immunosuppressants
• Have another health condition that affects your bones, such as osteoporosis, which causes you to lose bone mass and makes your bones more likely to break. Bone mass means the amount of bone tissue in your bones. 

Osteoporosis can happen in people with or without kidney disease, but people with CKD may have a higher risk.

Ask your doctor about your risk based on your CKD stage, lab results and health history.

What is CKD-MBD?

CKD can affect your bones in different ways. Some people develop chronic kidney disease-mineral and bone disorder, also called CKD-MBD. This is a broad condition that can develop when CKD causes changes in mineral and hormone levels. These changes can affect your bones, heart and blood vessels. One bone condition that can develop as part of CKD-MBD is renal osteodystrophy.

What is renal osteodystrophy

Renal osteodystrophy is a bone disease that can occur as part of CKD-MBD. It involves changes in how bone breaks down and rebuilds and can make bones more likely to fracture. Some people with CKD may have renal osteodystrophy without having symptoms at first but could have weak bones and bone pain.

Your doctor may use blood tests, imaging tests and your health history to understand what is causing your bone risk. 
 

What is osteoporosis?

Osteoporosis is a condition that makes bones weaker and more likely to break or fracture. It can happen in people with or without kidney disease, but people with CKD may have a higher risk. People with osteoporosis have decreased bone strength, which is often linked to low bone density or mass (how strong and thick your bones are). If you have osteoporosis, you lose bone mass faster than usual. Bone mass is the amount of bone tissue in your bones. Over time, this can lower your bone density and make your bones weaker and more likely to break. Some people with CKD may have osteoporosis and CKD-MBD at the same time. Because CKD can affect bone and mineral metabolism, some osteoporosis medicines may not be safe for everyone with CKD. Your doctor can help determine which treatment options are right for you based on your kidney function and bone health.

Is renal osteodystrophy the same as osteoporosis?

No, renal osteodystrophy and osteoporosis are different bone conditions. Renal osteodystrophy is the bone component of CKD-MBD and happens from changes in bone turnover and mineraliation associated with CKD. 

Osteoporosis is a condition that causes bones to lose strength and become more likely to break or have fractures, and it can happen in people with or without kidney disease. Both conditions can weaken bones and increase the risk of fractures. Some people with CKD may have both.

What complications can happen?

CKD-MBD can also lead to calcium and mineral build up in blood vessels, called vascular calcification. This can make blood vessels stiffer and is linked to a higher risk of heart and blood vessel problems. CKD-MBD can also affect children's bone growth and development.
 

How do doctors check bone health in people with kidney disease?

Your doctor may do a physical exam and ask about your symptoms, health history, medicines and any previous bone fractures or injuries. They may also do a series of tests including blood tests and imaging tests.

Blood tests are commonly used to monitor:

• Calcium
• Phosphorus
• Vitamin D
• PTH
• Alkaline phosphatase

Depending on your fracture risk, symptoms and CKD stage, your doctor may recommend imaging such as:

• X-rays to look for bone changes or fractures
• A dual-energy X-ray absorptiometry or DEXA scan, a test that uses low-dose X-rays  to measure bone density
• A computed tomography (CT) scan in some cases to look at calcifications
• An echocardiogram, also called an ECHO, which uses sound waves to create pictures of your heart

Rarely, a bone biopsy may be recommended. A bone biopsy, which involves removing a small sample of bone so it can be examined.

How is bone disease in CKD treated?

Treatment depends on your CKD stage, lab results, symptoms and overall health. Your care team may recommend changes to your eating plan, medicines, supplements, dialysis treatment, physical activity or surgery. Your treatment plan may change over time based on your lab results. Ask your doctor which treatment options are safe for you.

Nutrition and phosphorus

Talk with your doctor about what your phosphorus levels should be and whether you need to limit phosphorus in your foods, drinks or medicines.  Phosphorous is found naturally in many foods often in protein-rich food like dairy, meat, beans and nuts. There is also added phosphorous which is often in processed and pre-packaged foods.  A registered dietitian can help you create a meal plan that works for you. 

Medicines and supplements

Your doctor may recommend medicines or supplements to help manage mineral and bone problems.

These may include:

• Phosphate binders: medicines taken with meals that help reduce how much phosphorus your body absorbs from food in your digestive tract so less is absorbed into your bloodstream.
• Phosphate blockers: medicines that help reduce how much phosphorus your body absorbs from food through your digestive tract.
• Vitamin D
• Active vitamin D
• Calcimimetics: medicines that act like calcium in the body and help lower PTH levels
• Calcium supplements
• Osteoporosis medicines

Some medicines used to treat osteoporosis may not be appropriate for everyone with CKD. Your doctor will consider your kidney function, fracture risk and mineral and hormone levels when deciding whether osteoporosis treatment is right for you. 

Do not start calcium, vitamin D or bone health supplements without asking your doctor. Some supplements can be harmful for people with kidney disease or may affect your calcium and phosphorus levels.

Dialysis and bone health

Dialysis can help remove extra phosphorus from your blood, but it does not treat every part of CKD-MBD by itself. If you are on dialysis, your care team may check your phosphorus, calcium and PTH levels regularly. Your dialysis schedule, treatment settings, medicines and eating plan may all affect your phosphorus levels. Ask your dialysis care team if your phosphorus is in your goal range. You can also ask whether any changes to your dialysis treatment or medicines may help.
 

Bone health after a kidney transplant

Bone health can still be a concern after a kidney transplant. Some people may have weak bones before transplant because of CKD-MBD, dialysis, low vitamin D or changes in calcium, phosphorus and PTH. Some medicines used after transplant, including steroids, may also affect bone health. .

Physical activity

Physical activity can help support bone strength, muscle strength and balance. Better balance and strength may help lower the risk of falls and fractures.

Helpful activities may include weight-bearing exercises, such as:

• Walking
• Resistance (using bands) or light strength training
• Stretching
• Balance exercises like yoga or tai chi

How can I help protect my bones if I have kidney disease?

You can help protect your bones by working with your doctor and care team. Ask about your calcium, phosphorus, vitamin D and PTH levels and whether they are in a safe range.

You can also:

• Take medicines as prescribed and tell your healthcare team if you have difficulty taking them.
• Complete dialysis treatments if you are on dialysis
• Ask what types of physical activity are safe for you
• Ask for a recommendation for a physical therapist
• Talk with your doctor about your risk for falls and fractures
• Avoid tobacco products
• Limit alcohol if your doctor recommends it
• Ask whether you need a DEXA scan or other bone health tests

Can bone damage from kidney disease be reversed?

Some bone and mineral problems may improve with treatment, especially when they are found early but it depends on the type and severity of bone disease. Some mineral and hormone abnormalities related to CKD can improve with treatment. Treatment may also slow or prevent additional bone damage and reduce fracture risk. However, existing bone changes may not always be completely reversed. Treatments can help bring phosphorus, calcium, vitamin D and PTH closer to a safer range and lower the risk of more bone damage.

When to call your doctor

Call your doctor if you have:

• New or worsening bone or joint pain
• A broken bone
• A fall
• Muscle weakness or muscle cramps that do not improve
• Trouble walking or moving around
• New numbness, tingling or burning pain
• Severe itching
• Symptoms that make daily activities harder

Related AKF resources

• CKD stages
• Phosphorus and kidney disease
• Dialysis
• Medicines for kidney disease
• Kidney transplant