Definition

Rickets is disease resulting from a vitamin D shortage in children. It causes bones to soften and weaken.

Rickets

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Causes

Rickets results when there is a vitamin D or calcium shortage in a child's body. This may occur when:

• The supply of vitamin D from diet or sun exposure is too low.
• The way the body processes vitamin D is not typical.
• Tissue does not respond to the action of vitamin D.

Vitamin D controls how calcium is absorbed in the body. It also controls levels of calcium and phosphate in bone. Vitamin D is absorbed in the intestines from food. Vitamin D is also produced by the skin during exposure to sunlight.

Most often, rickets is caused by a shortage of vitamin D. This can result from:

• Not enough vitamin D in the diet. In children, this may be related to:
  • Not drinking enough vitamin D-fortified milk
  • Not giving enough vitamin D supplements to children being breastfed or to children who are lactose intolerant
• Lack of exposure to sunlight

Less often, rickets can be caused by other disorders that affect vitamin D absorption, processing, or action in the body such as:

• Kidney problems:
  • A hereditary disorder of the kidney called vitamin D-resistant rickets
  • Renal tubular acidosis—a non-hereditary kidney disorder that causes bone calcium to dissolve
  • Chronic kidney failure
  • Long-term kidney dialysis
• Diseases of the small intestines with malabsorption
• Disorders of the liver or pancreas disease
• Cancer
• Certain drugs, such as:
  • Certain seizure medications, such as phenytoin or phenobarbital
  • Acetazolamide
  • Ammonium chloride
  • Disodium etidronate
  • Fluoride treatment
• Toxicity or poisoning from:
  • Cadmium
  • Lead
  • Aluminum
  • Outdated tetracycline

Risk Factors

Factors that may increase your child's chances of getting rickets include:

• Lack of sun exposure
• Age in children: 6 to 24 months
  • Babies who are breastfed—breast milk is low in vitamin D
  • Babies who do not drink enough formula that is fortified with vitamin D
  • Children who do not drink enough vitamin D-fortified milk
• Lactose intolerance with low intake of vitamin D-fortified milk
• Family history of rickets
• Race: Black, especially in association with breastfeeding
• Certain chronic illnesses that result in loss of or poor absorption of calcium

Symptoms

Symptoms may include:

• Bone pain and tenderness
• Skeletal and/or skull deformities
• Bow legs or knock knees
• Deformity or curvature of the spine
• Pigeon chest—a chest that protrudes
• Impaired growth, resulting in short stature
• Bone fractures
• Dental deformities
• Delayed tooth formation
• Defects in teeth
• Increased cavities
• Loss of appetite or weight loss
• Difficulty sleeping
• Poor muscle development and tone
• Muscle weakness
• Delayed walking

Diagnosis

The doctor will ask about your child's symptoms and medical history. A physical exam will be done.

• Your child's bodily fluid and bone may be tested. This can be done with:
  • Blood tests
  • Urine tests
  • Bone biopsy —when other tests are not conclusive
• Pictures may be taken of structures inside your child's body. This can be done with an x-ray.

Treatment

Treatment attempts to:

• Correct the underlying cause
• Relieve or reverse symptoms

Prevention

To help prevent rickets, your child should:

• Drink vitamin D-fortified milk.
• Consume enough vitamin D, calcium, and other minerals. If you think your child's diet may be deficient, talk with the doctor about other sources of vitamins and minerals.
• Get sufficient, but not excessive, exposure to sunlight. Fifteen minutes a day is usually enough. Any longer than that requires sun protection with clothing or sunscreens, especially in fair-skinned infants and children. Children with dark skin are at increased risk for rickets and may need more sun exposure and dietary supplementation with vitamin D.
• Breastfed babies and bottle-fed babies who do not get enough vitamin-D fortified formula may need to be given a supplement starting within the first few days of life. Children not getting at least 400 units of vitamin D from their diet may also need supplements. Talk to the doctor to make sure your child is meeting the nutritional requirements for vitamin D.