Vitamin D-Resistant Rickets

What is vitamin D-resistant rickets?

Vitamin D-resistant rickets, also called hypophosphatemic rickets, is a genetic condition that causes low levels of the mineral phosphate in the blood. Phosphate is needed in the body to form bones and teeth. When a child does not have enough phosphate, they will have soft bones that bend easily. Vitamin D-resistant rickets can also cause bone pain, fractures and dental problems.

Vitamin D-resistant rickets usually runs in families. It can vary from mild to severe.

What are the signs and symptoms of vitamin D-resistant rickets?

The symptoms of vitamin D-resistant rickets can vary from one child to another, even within the same family. Children with the condition usually start having symptoms by the time they are walking. Some common symptoms in children include:

• Bone pain
• Bone weakness
• Bowed legs
• Knock knees
• Muscle weekness
• Being shorter than their peers
• Failure to thrive
• Joint stiffness
• Dental problems

What causes vitamin D-resistant rickets?

In most cases, vitamin D-resistant rickets is passed down in families. It happens when a mutation occurs in a specific gene.

The genes connected with vitamin D-resistant rickets help control the proper balance of phosphate in the body. Phosphate plays an important role in bone development and bone strength. Usually, the kidneys excrete extra phosphate in the urine, and reabsorb phosphate into the bloodstream when the body needs more. But because of the gene mutation, children with vitamin D-resistant rickets cannot reabsorb enough phosphorus for the bones to grow properly.

How is vitamin D-resistant rickets treated?

Most children with vitamin D-resistant rickets are treated with oral phosphate and vitamin D. Your care team at Arkansas Children’s is experienced in treating vitamin D-resistant rickets and will work with you to create the best treatment plan for your child.