Chronic Kidney DiseaseMineral and Bone Disorder 

What is chronic kidney diseasemineral and bone disorder 

(CKD-MBD)? 

CKD-MBD occurs when the kidneys fail to 

maintain the proper levels of calcium and 

phosphorus in the blood, leading to abnormal bone hormone levels. CKD-MBD is 

a common problem in people with kidney disease and affects almost all patients 

receiving dialysis. 

CKD-MBD is most serious in children 

because their bones are still growing. The 

condition slows bone growth and causes 

deformities. One such deformity occurs 

when the legs bend inward toward each 

other or outward away from each other; 

this deformity is referred to as “renal rickets.” Another serious complication is short 

stature. Symptoms can be seen in growing 

children with renal disease even before they 

start dialysis. 

The bone changes from CKD-MBD can 

begin many years before symptoms appear 

in adults with kidney disease. For this 

reason, the disease is known as a “silent 

crippler.” If CKD-MBD in adults is left 

untreated, the bones gradually become thin 

and weak, and a person with CKD-MBD 

may begin to feel bone and joint pain. 

CKD-MBD also increases the risk of bone 

fractures. 

Doctors used to use the term renal osteodystrophy to describe the mineral and 

hormone disturbances caused by kidney 

disease. Now renal osteodystrophy is used 

only to describe the bone problems that 

result from CKD-MBD. 

Why are hormones and minerals 

important? 

In healthy adults, bone tissue is continually 

being remodeled and rebuilt. The kidneys play an important role in maintaining 

healthy bone mass and structure because 

one of their jobs is to balance calcium and 

phosphorus levels in the blood and ensure 

the vitamin D a person receives from sunlight and food becomes activated. 

Calcium is a mineral that builds and 

strengthens bones. Calcium is found in 

many foods, particularly milk and other 

dairy products. If calcium levels in the 

blood become too low, four small glands 

in the neck called the parathyroid glands 

release a hormone called parathyroid hormone (PTH). This hormone draws calcium 

from the bones to raise blood calcium 

levels. Too much PTH in the blood will 

remove too much calcium from the bones; 

over time, the constant removal of calcium 

weakens the bones. 

Phosphorus, an element found in most 

foods, also helps regulate calcium levels in 

the bones. Healthy kidneys remove excess 

phosphorus from the blood. When the 

kidneys stop working normally, phosphorus 

levels in the blood can become too high, 

leading to lower levels of calcium in the 

blood and resulting in higher PTH levels 

and the loss of calcium from the bones. 

Even before blood levels of phosphorus 

become elevated, the kidneys are forced to 

work harder to clear phosphorus from the 

body. 

Healthy kidneys produce calcitriol from 

vitamin D that is received from sunlight 

U.S. Department of Health
 

and Human Services
 

NATIONAL INSTITUTES OF HEALTH 

National Kidney and Urologic Diseases 

Information Clearinghouse
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

and food. Calcitriol helps the body absorb dietary 

calcium and phosphorus into the blood and bones. 

Calcitriol and PTH work together to keep calcium 

balance normal and bones healthy. If calcitriol 

levels drop too low, PTH levels increase and calcium is removed from the bones. In a person with 

kidney failure, the kidneys stop making calcitriol. 

The body then cannot absorb calcium from food, 

leading to increased PTH levels. The combination 

of decreased calcium absorption from food and 

PTH drawing calcium from bones makes the bones 

weak and brittle. 

How is CKD-MBD diagnosed? 

To diagnose CKD-MBD, a doctor may take a 

blood sample to measure levels of calcium, phosphorus, PTH, and sometimes vitamin D. The doctor may perform a bone biopsy to see if the bone 

cells are building normal bone. A bone biopsy is 

done under local anesthesia and involves removing 

a small sample of bone from the hip and analyzing 

it with a microscope. Determining the cause of 

CKD-MBD helps the doctor decide on a course of 

treatment. 

How is CKD-MBD treated? 

Controlling PTH levels prevents damage to bones. 

Usually, overactive parathyroid glands are controllable with a change in diet, dialysis treatment, or 

medication. 

CKD-MBD can be treated with changes in diet. 

Reducing dietary intake of phosphorus is one 

of the most important steps in preventing bone 

disease. Almost all foods contain phosphorus, 

but it is especially high in milk, cheese, dried 

beans, peas, nuts, and peanut butter. Drinks such 

These medications decrease the absorption of phosphorus into 

the blood. 

as cocoa, dark sodas, and beer are also high in 

phosphorus. Often, medications called phosphate 

binders—such as calcium carbonate (Tums), calcium acetate (PhosLo), sevelamer hydrochloride 

(Renagel), or lanthanum carbonate (Fosrenol)—are 

prescribed with meals and snacks to bind phosphorus in the bowel. These medications decrease the 

absorption of phosphorus into the blood. A renal 

dietitian can help develop a dietary plan to control 

phosphorus levels in the blood. 

Increasing dialysis dose by increasing a patient’s 

flow rate or time in treatment can also help control phosphorus. 

If the kidneys are not making adequate amounts of 

calcitriol, a person can take synthetic calcitriol as 

a pill (Rocaltrol) or in an injectable form (Calijex). 

Other types of vitamin D that may be prescribed 

are ergocalciferol (Calciferol, Drisdol), cholecalciferol (Delta D3), doxercalciferol (Hectoral), and 

paricalcitol (Zemplar). A doctor may prescribe a 

calcium supplement in addition to calcitriol. The 

drug cinacalcet hydrochloride (Sensipar), approved 

by the U.S. Food and Drug Administration in 

2004, lowers PTH levels by imitating calcium’s 

effects on the parathyroid gland. If PTH levels 

cannot be controlled, the parathyroid glands may 

need to be removed surgically. 

A good treatment program, including proper 

attention to diet, dialysis, and medications, can 

improve the body’s ability to repair bones damaged by CKD-MBD. Overall bone health can also 

be improved by exercising and not smoking. People on dialysis should consult a health care professional before beginning any exercise program. 

Points to Remember 

n Chronic kidney disease-mineral and bone disorder (CKD-MBD) occurs when the kidneys fail 

to maintain the proper levels of calcium and 

phosphorus in the blood. 

n CKD-MBD is a common problem in people 

with kidney disease and affects almost all 

patients receiving dialysis. 

n If calcium levels in the blood become too low, 

or phosphorus levels too high, four small glands 

in the neck called the parathyroid glands release 

a hormone called parathyroid hormone (PTH). 

This hormone draws calcium and phosphorus 

from the bones to raise blood calcium levels. 

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n	 Healthy kidneys convert vitamin D into calcitriol to help the body absorb dietary calcium and 

phosphorus into the blood and bones. If calcitriol levels drop too low, PTH levels increase 

and the bones can become weak and brittle. 

n	 Reducing dietary intake of phosphorus is one 

of the most important steps in preventing bone 

disease. 

n	 Medications called phosphate binders are prescribed with meals and snacks to bind phosphorus in the bowel. 

n	 Increasing dialysis dose by increasing a patient’s 

flow rate or time in treatment can also help 

control phosphorus. 

n	 If the kidneys are not making adequate amounts 

of calcitriol, a person can take synthetic calcitriol or other forms of vitamin D as a pill or in 

an injectable form. 

n	 If PTH levels cannot be controlled, the parathyroid glands may need to be removed surgically. 

Hope through Research 

The National Institute of Diabetes and Digestive 

and Kidney Diseases (NIDDK), through its Division of Kidney, Urologic, and Hematologic Diseases, supports several programs and studies devoted 

to improving treatment for patients with progressive kidney disease and end-stage kidney failure, 

which is sometimes called end-stage renal disease 

or ESRD, including patients on hemodialysis: 

n	 The End-Stage Renal Disease Program. This 

program promotes research to reduce medical 

problems from bone, blood, nervous system, 

metabolic, gastrointestinal, cardiovascular, and 

endocrine abnormalities in end-stage kidney 

failure and to improve the effectiveness of dialysis and transplantation. The research focuses 

on reuse of hemodialysis membranes and using 

alternative dialyzer sterilization methods; devising more efficient, biocompatible membranes; 

refining high-flux hemodialysis; and developing criteria for dialysis adequacy. The program 

also seeks to increase kidney graft and patient 

survival and maximize quality of life. 

n	 The Frequent Hemodialysis Network. This 

multicenter clinical trial will test whether 

receiving hemodialysis more than the standard 

three times a week provides better outcomes. 

n	 The U.S. Renal Data System (USRDS). This 

national data system collects, analyzes, and 

distributes information about the use of dialysis and transplantation to treat kidney failure 

in the United States. The USRDS is funded 

directly by the NIDDK in conjunction with the 

Centers for Medicare & Medicaid Services. 

The USRDS publishes an Annual Data Report, 

which characterizes the total population of 

people being treated for kidney failure; reports 

on incidence, prevalence, mortality rates, and 

trends over time; and develops data on the 

effects of various treatment modalities. The 

report also helps identify barriers to the delivery of quality health care and opportunities for 

more focused studies of renal research issues. 

n	 The Hemodialysis Vascular Access Clinical 

Trials Consortium. This program is conducting 

a series of multicenter, randomized, placebocontrolled clinical trials of drug therapies to 

reduce the failure and complication rate of arteriovenous grafts and fistulas in hemodialysis. 

Recently developed anti-thrombotic agents and 

drugs to inhibit cytokines are being evaluated in 

these large clinical trials. 

Participants in clinical trials can play a more active 

role in their own health care, gain access to new 

research treatments before they are widely available, and help others by contributing to medical 

research. For information about current studies, 

visit www.ClinicalTrials.gov. 

For More Information 

American Association of Kidney Patients 

3505 East Frontage Road, Suite 315 

Tampa, FL 33607 

Phone: 1–800–749–2257 

Fax: 813–636–8122 

Email: info@aakp.org 

Internet: www.aakp.org 

American Kidney Fund 

6110 Executive Boulevard, Suite 1010 

Rockville, MD 20852 

Phone: 1–800–638–8299 or 301–881–3052 

Fax: 301–881–0898 

Email: helpline@akfinc.org 

Internet: www.kidneyfund.org 

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National Kidney Foundation 

30 East 33rd Street 

New York, NY 10016 

Phone: 1–800–622–9010 or

 212–889–2210 

Fax: 212–689–9261 

Internet: www.kidney.org 

Kidney Disease: Improving Global Outcomes 

30 East 33rd Street, Suite 900 

New York, NY 10016 

Phone: 212–889–3427 

Internet: www.kdigo.org 

Acknowledgments 

Publications produced by the Clearinghouse 

are carefully reviewed by both NIDDK 

scientists and outside experts. This publication was reviewed by Mary Leonard, M.D., 

University of Pennsylvania Health System, 

Philadelphia, and Sharon Moe, M.D., 

Indiana University School of Medicine, 

Indianapolis. 

About the Kidney Failure Series 

The NIDDK Kidney Failure Series includes 

booklets and fact sheets that can help you 

learn more about treatment methods for 

kidney failure, complications of dialysis, 

financial help for the treatment of kidney 

failure, and eating right on hemodialysis. For free single printed copies of this 

series, please contact the National Kidney and Urologic Diseases Information 

Clearinghouse. 

You may also find additional information about this 

topic by 

• searching the NIDDK Reference Collection at 

www.catalog.niddk.nih.gov/resources

•	 visiting MedlinePlus at www.medlineplus.gov

This publication may contain information about medications. When prepared, this publication included 

the most current information available. For updates 

or for questions about any medications, contact 

the U.S. Food and Drug Administration toll-free at 

1–888–INFO–FDA (463–6332) or visit www.fda.gov. 

Consult your doctor for more information. 

National Kidney and Urologic 

Diseases Information Clearinghouse 

3 Information Way 

Bethesda, MD 20892–3580 

Phone: 1–800–891–5390 

TTY: 1–866–569–1162 

Fax: 703–738–4929 

Email: nkudic@info.niddk.nih.gov 

Internet: www.kidney.niddk.nih.gov 

The National Kidney and Urologic Diseases 

Information Clearinghouse (NKUDIC) 

is a service of the National Institute of 

Diabetes and Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the 

National Institutes of Health of the U.S. 

Department of Health and Human Services. 

Established in 1987, the Clearinghouse 

provides information about diseases of the 

kidneys and urologic system to people with 

kidney and urologic disorders and to their 

families, health care professionals, and the 

public. The NKUDIC answers inquiries, 

develops and distributes publications, and 

works closely with professional and patient 

organizations and Government agencies to 

coordinate resources about kidney and 

urologic diseases. 

This publication is not copyrighted. The Clearinghouse encourages users of this fact sheet to duplicate 

and distribute as many copies as desired. 

This fact sheet is also available at 

www.kidney.niddk.nih.gov. 

The U.S. Government does not endorse or favor any 

specific commercial product or company. Trade, 

proprietary, or company names appearing in this 

document are used only because they are considered 

necessary in the context of the information provided. 

If a product is not mentioned, the omission does not 

mean or imply that the product is unsatisfactory. 

U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES 

National Institutes of Health 

NIH Publication No. 09–4630 

February 2009