The damage to the kidneys at late stage:
- limit the production of activated vitamin D
- prevents the kidneys from removing excessive phosphate from the blood
This causes a hormonal imbalance which interferes with the production of healthy bone.
People with chronic kidney disease usually have low levels of activated vitamin D. This is because healthy kidneys activate the vitamin D produced in your skin from sunlight and from food. Your kidney doctor may prescribe you the active form of vitamin D, which is different from that which can be bought from health shops and pharmacies.
Phosphate comes from the diet, mainly from dairy produce, red meat, eggs and fish products. You may be advised by renal dietition on how to limit the amount of foods you eat that contain phosphate, without reducing your healthy intake of other nutrients.
If reducing the amount of phosphate in your diet does not lower your blood phosphate level enough, you may be prescribed medicines called phosphate binders. These bind to the phosphate contained in the food, inside your stomach, and stop it from being absorbed into your blood stream.