Your kidneys play an important role in keeping your bones healthy. People with kidney disease often develop problems with their bones.
How do kidneys keep bones healthy?
You need calcium and vitamin D to have healthy bones. Healthy kidneys help keep your bones healthy. They do this in two ways.
- Your kidneys keep the right amounts of phosphorus and calcium in your body. When your kidneys are not working, too much phosphorus can build up in your blood. This is called hyperphosphatemia. This can cause your body to pull calcium from your bones, making them weak.
- Your kidneys help your body use vitamin D. When your kidneys are not working, your body may not be able to use vitamin D like it should. This can also cause your bones to get weak.
Calcium is a mineral that is found in many foods. Milk, cheese and yogurt are very high in calcium. A hormone called parathyroid hormone (PTH) helps your body keep the right amount of calcium in your blood.
Phosphorus is a mineral that is found in almost all foods. Foods and drinks that are very high in phosphorus include:
- Milk and cheese
- Red meat
- Dried beans and peas
- Nuts and nut butters
- Whole grain bread
- Dark-colored sodas
Vitamin D is in some foods naturally, but most foods that are good sources of vitamin D have the vitamin D added to them during processing. Your body also gets vitamin D from the sun, when your skin is exposed to sunlight.
How will I know if I have bone disease?
Bone disease often does not have any symptoms until your bones are very weak. The only way to know if you have bone disease is to be tested. Tests for bone health might include:
- Blood tests to check for:
- Parathyroid hormone (PTH)
- Vitamin D
- Bone density scan or X-ray
- Bone biopsy (rare).
Bone disease can cause bone and joint pain, broken bones, infections and skin problems. Having problems with the amount of calcium and phosphorus in your blood can also cause heart attacks.
How can I prevent bone disease?
If you have kidney disease, it is important to take steps to prevent bone disease.
- Limit how much phosphorus you take in each day. Ask your doctor or dietitian to tell you how much phosphorus you should have. You can also ask for a list of high-phosphorus foods and lower-phosphorus alternatives. Write down how much phosphorus you eat or drink at each meal to make sure you are not getting too much.
- Take a phosphate binder. This is a medicine that you take with meals to keep your body from taking in the phosphorus that comes from your foods and drinks. This can help keep phosphorus from building up in your blood.
- Take a calcitriol supplement. Your kidneys make calcitriol using the vitamin D you get from food and the sun. When your kidneys are not working, they cannot make calcitriol. A man-made form of calcitriol can help your body use the calcium and phosphorus it needs.
- Exercise. This can help make your bones stronger and keep them from breaking.
- Do not smoke or use tobacco. Smoking and using tobacco can make bone disease worse.
- Follow your treatment plan. Take your medicines the way your doctor tells you to and do not skip dialysis treatments! Your medicines and dialysis help get rid of extra phosphorus that can cause bone disease.
- Adjust your treatment plan. Having more dialysis can help your body get rid of extra phosphorus. If you still have too much phosphorus in your blood after changing your diet and taking medicines, your doctor might suggest that you have more dialysis.