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For children 6 months or older,

Early diagnosis and treatment of XLH can help manage your child’s symptoms

For children 6 months and older with XLH, early diagnosis and treatment is important to help manage low phosphorus levels in the blood, rickets, and delayed growth.

DNA helix

XLH is a rare, lifelong, genetic disease that can get worse over time when left untreated.

Triangle with exclamation point in center

XLH affects up to 1 in 20,000 people and can impact the bones and muscles of both children and adults.

Sad face

Children with XLH don’t have enough phosphorus in their bodies. Phosphorus is a mineral that is important to the health of bones and muscles. When phosphorus levels are too low, it is called hypophosphatemia.

This can cause something called rickets, a condition where growing bone weakens over time, leading to lower limb abnormalities.

Cera, a real CRYSVITA patient, standing next to a tree

Cera, real CRYSVITA patient

Did you know? XLH often runs in the family

XLH is a hereditary condition. People can inherit XLH from either their father or mother. If one member of the family has XLH, there is a good chance that other members may have it, too.

Family tree showing how XLH is passed down from parents to children

Signs of XLH in children

One of the first signs of XLH in children is rickets, which is the softening and weakening of growing bone. This typically appears as bowed legs or knock knees when a child begins to walk and put weight on their legs.

Over time, bone weakening can also lead to:

Bowed bones

Bone abnormalities in the legs

Baby

Delayed growth

Short stature

Managing XLH in children

Be sure to talk to your child's doctor about treatment goals and options for your child with XLH.

Because XLH is a lifelong condition, treatment goals may change at different stages of life, including into adulthood.

Treatment goals for children with XLH may include:

Periodic table abbreviation for phosphorus

Increasing and maintaining phosphorus levels in the blood

Bone with rickets

Helping to heal rickets

Improving growth

Ready to experience CRYSVITA?

Start the conversation with your child's doctor today.

Crysvita for Children

Learn about the possibilities of treating XLH with CRYSVITA

See CRYSVITA results in children

Discover how CRYSVITA helped children with XLH

See safety information for CRYSVITA

Learn about the safety profile of CRYSVITA

Find helpful CRYSVITA resources

Tools that can support your CRYSVITA journey

Stay informed

Learn more about CRYSVITA, connect with a support community, and receive invites to important educational events.

What is CRYSVITA?

CRYSVITA is a prescription medicine used to treat adults and children 6 months of age and older with X-linked hypophosphatemia (XLH).

What is CRYSVITA?

CRYSVITA is a prescription medicine used to treat adults and children 6 months of age and older with X-linked hypophosphatemia (XLH).

Important Safety Information

You should not take CRYSVITA if:

You take an oral phosphate supplement and/or a specific form of vitamin D supplement (such as calcitriol, paricalcitol, doxercalciferol, calcifediol).

Your phosphorus levels from a blood sample are within or above the normal range for age.
You have kidney problems.

What is the most important information you should know about CRYSVITA?

Some patients developed allergic reactions (e.g., rash and hives) while taking CRYSVITA. Your doctor will monitor you for symptoms of an allergic reaction while you are taking CRYSVITA. Your treatment may need to be discontinued for serious allergic reactions.
High levels of phosphorus in the blood have been reported in some patients taking CRYSVITA. This may be related to a risk of high calcium levels in the kidneys. Your doctor will collect blood samples to monitor your levels. If you are already taking CRYSVITA, dose interruption and/or dose reduction may be required based on your serum phosphorus levels.
Administration of CRYSVITA may result in reactions at the injection site, such as hives, reddening of the skin, rash, swelling, bruising, pain, severe itching of the skin, and collection of blood outside of a blood vessel (i.e., hematoma). Call your doctor if you develop an injection site reaction. CRYSVITA may be discontinued if severe injection site reactions occur.

What are the possible side effects of CRYSVITA?

Adverse reactions that were seen in children with XLH are:
- Fever
- Injection site reaction
- Cough
- Vomiting
- Pain in arms and legs
- Headache
- Tooth abscess
- Dental cavities
- Diarrhea
- Decreased vitamin D levels
- Toothache
- Constipation
- Muscle pain
- Rash
- Dizziness
- Nausea
Adverse reactions that were seen in adults with XLH are:
- Back pain
- Headache
- Tooth infection
- Restless legs syndrome
- Decreased vitamin D levels
- Dizziness
- Constipation
- Muscle spasms
- Phosphorus levels increased in the blood
Narrowing of the spaces within the spine is common in adults with XLH, and pressure on the spinal cord has been reported in adults taking CRYSVITA. It is not known if taking CRYSVITA worsens the narrowing of the spaces within the spine or the pressure on the spinal cord.

Before taking CRYSVITA, tell your doctor about all of your medications (including supplements) and medical conditions, including if you:

Are taking oral phosphate and/or active vitamin D (such as calcitriol, paricalcitol, doxercalciferol, calcifediol).
Are pregnant, think you may be pregnant, or plan to become pregnant. There is not enough experience to know if CRYSVITA may harm your unborn baby. Report pregnancies to the Kyowa Kirin, Inc. Adverse Event reporting line at 1-844-768-3544.
Are breastfeeding or plan to breastfeed. There is not enough experience to know if CRYSVITA passes into your breast milk. Talk with your doctor about the best way to feed your baby while you receive CRYSVITA.

While taking CRYSVITA, tell your doctor if you experience:

An allergic reaction such as rash or hives
A rash, swelling, bruising, or other reaction at the injection site
New or worsening restless legs syndrome

These are not all the possible side effects of CRYSVITA. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at (800) FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Kyowa Kirin, Inc. at 1-844-768-3544.

For important risk and use information, please see the full Prescribing Information.

What is CRYSVITA?

CRYSVITA is a prescription medicine used to treat adults and children 6 months of age and older with X-linked hypophosphatemia (XLH).

Important Safety Information

You should not take CRYSVITA if:

You take an oral phosphate supplement and/or a specific form of vitamin D supplement (such as calcitriol, paricalcitol, doxercalciferol, calcifediol).
Your phosphorus levels from a blood sample are within or above the normal range for age.
You have kidney problems.

What is the most important information you should know about CRYSVITA?

Some patients developed allergic reactions (e.g., rash and hives) while taking CRYSVITA. Your doctor will monitor you for symptoms of an allergic reaction while you are taking CRYSVITA. Your treatment may need to be discontinued for serious allergic reactions.
High levels of phosphorus in the blood have been reported in some patients taking CRYSVITA. This may be related to a risk of high calcium levels in the kidneys. Your doctor will collect blood samples to monitor your levels. If you are already taking CRYSVITA, dose interruption and/or dose reduction may be required based on your serum phosphorus levels.
Administration of CRYSVITA may result in reactions at the injection site, such as hives, reddening of the skin, rash, swelling, bruising, pain, severe itching of the skin, and collection of blood outside of a blood vessel (i.e., hematoma). Call your doctor if you develop an injection site reaction. CRYSVITA may be discontinued if severe injection site reactions occur.

What are the possible side effects of CRYSVITA?

Adverse reactions that were seen in children with XLH are:
- Fever
- Injection site reaction
- Cough
- Vomiting
- Pain in arms and legs
- Headache
- Tooth abscess
- Dental cavities
- Diarrhea
- Decreased vitamin D levels
- Toothache
- Constipation
- Muscle pain
- Rash
- Dizziness
- Nausea
Adverse reactions that were seen in adults with XLH are:
- Back pain
- Headache
- Tooth infection
- Restless legs syndrome
- Decreased vitamin D levels
- Dizziness
- Constipation
- Muscle spasms
- Phosphorus levels increased in the blood
Narrowing of the spaces within the spine is common in adults with XLH, and pressure on the spinal cord has been reported in adults taking CRYSVITA. It is not known if taking CRYSVITA worsens the narrowing of the spaces within the spine or the pressure on the spinal cord.

Before taking CRYSVITA, tell your doctor about all of your medications (including supplements) and medical conditions, including if you:

Are taking oral phosphate and/or active vitamin D (such as calcitriol, paricalcitol, doxercalciferol, calcifediol).
Are pregnant, think you may be pregnant, or plan to become pregnant. There is not enough experience to know if CRYSVITA may harm your unborn baby. Report pregnancies to the Kyowa Kirin, Inc. Adverse Event reporting line at 1-844-768-3544.
Are breastfeeding or plan to breastfeed. There is not enough experience to know if CRYSVITA passes into your breast milk. Talk with your doctor about the best way to feed your baby while you receive CRYSVITA.

While taking CRYSVITA, tell your doctor if you experience:

An allergic reaction such as rash or hives
A rash, swelling, bruising, or other reaction at the injection site
New or worsening restless legs syndrome

These are not all the possible side effects of CRYSVITA. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at (800) FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Kyowa Kirin, Inc. at 1-844-768-3544.

For important risk and use information, please see the full Prescribing Information.