Overview Of Rickets
Rickets is a disorder caused by a lack of vitamin D, calcium, or phosphate. It leads to softening and weakening of the bones.
Commonly Associated With
Osteomalacia in children; Vitamin D deficiency; Renal rickets; Hepatic rickets
Causes Of Rickets
Vitamin D helps the body control calcium and phosphate levels. If the blood levels of these minerals become too low, the body may produce hormones that cause calcium and phosphate to be released from the bones. This leads to weak and soft bones.
Vitamin D is absorbed from food or produced by the skin when exposed to sunlight.
Lack of vitamin D production by the skin may occur in people who:
- Live in climates with little exposure to sunlight
- Must stay indoors
- Work indoors during the daylight hours
You may not get enough vitamin D from your diet if you:
- Are lactose intolerant (have trouble digesting milk products)
- DO NOT drink milk products
- Follow a vegetarian diet
- Infants who are breastfed only may develop vitamin D deficiency. Human breast milk does not supply the proper amount of vitamin D. This can be a particular problem for darker-skinned children in the winter months. This is because there are lower levels of sunlight during these months.
Not getting enough calcium and phosphorous in your diet can also lead to rickets. Rickets caused by a lack of these minerals in the diet is rare in developed countries. Calcium and phosphorous are found in milk and green vegetables.
Your genes may increase your risk of rickets. Hereditary rickets is a form of disease that is passed down through families. It occurs when the kidneys are unable to hold onto the mineral phosphate. Rickets may also be caused by kidney disorders that involve renal tubular acidosis.
Disorders that reduce the digestion or absorption of fats will make it more difficult for vitamin D to be absorbed into the body.
Sometimes, rickets may occur in children who have disorders of the liver. These children cannot convert vitamin D to its active form.
Rickets is rare in the United States. It is most likely to occur in children during periods of rapid growth. This is the age when the body needs high levels of calcium and phosphate. Rickets may be seen in children ages 6 to 24 months. It is uncommon in newborns.
Symptoms Of Rickets
Symptoms of rickets include:
- Bone pain or tenderness in the arms, legs, pelvis, and spine
- Decreased muscle tone (loss of muscle strength) and weakness that gets worse
- Dental deformities, including delayed tooth formation, defects in the tooth structure, holes in the enamel, and increased cavities (dental caries)
- Impaired growth
- Increased bone fractures
- Muscle cramps
- Short stature (adults less than 5 feet or 1.52 meters tall)
- Skeletal deformities such as an odd-shaped skull, bowlegs, bumps in the ribcage (rachitic rosary), breastbone that is pushed forward (pigeon chest), pelvic deformities, and spine deformities (spine that curves abnormally, including scoliosis or kyphosis)
Exams & Tests
A physical exam reveals tenderness or pain in the bones, but not in the joints or muscles.
The following tests may help diagnose rickets:
- Arterial blood gases
- Blood tests (serum calcium)
- Bone biopsy (rarely done)
- Bone x-rays
- Serum alkaline phosphatase (ALP)
- Serum phosphorus
Other tests and procedures include the following:
- ALP isoenzyme
- Calcium (ionized)
- Parathyroid hormone (PTH)
- Urine calcium
Treatment Of Rickets
The goals of treatment are to relieve symptoms and correct the cause of the condition. The cause must be treated to prevent the disease from returning.
Replacing calcium, phosphorus, or vitamin D that is lacking will eliminate most symptoms of rickets. Dietary sources of vitamin D include fish liver and processed milk.
Exposure to moderate amounts of sunlight is encouraged. If rickets is caused by a metabolic problem, a prescription for vitamin D supplements may be needed.
Positioning or bracing may be used to reduce or prevent deformities. Some skeletal deformities may require surgery to correct them.