Vitamin D Deficiency, (Rickets) | Symptoms & Causes | Diagnosis
 


What this section contains?
1. What is Vitamin D Deficiency, (Rickets)?
2. Cause
3. Diagnosis & Tests
4. Prevention & Risk Factors
5. Treatments & Therapies
Vitamin D Deficiency, (Rickets)

What is Vitamin D Deficiency, (Rickets)?

Rickets is a bone disorder caused by a deficiency of vitamin D, calcium, or phosphate. There are different bony abnormalities associated with rickets, but all are due to poor mineralization with calcium and phosphate. The active form of vitamin D is synthesized by skin cells when exposed to sunlight.

Vitamin D is naturally formed in the body by exposure to sunlight. Spending more time indoors, watching T.V. and computer while compromising on time spent outside during daytime, could result in Vitamin D deficiency. Prolong deficiency of Vitamin D may be lead to Rickets, in children. It is estimated that around 80% of Indian population has lower levels of Vitamin D than normal level although visible deficiency states (rickets) may be quite less at 12.5% using biochemical and radiological analysis.

Cause

Maternal deficiencies may be the cause of overt bone disease from before birth and impairment of bone quality after birth. The primary cause of congenital rickets is vitamin D deficiency in the mother's blood, which the baby shares. Vitamin D ensures that serum phosphate and calcium levels are sufficient to facilitate the mineralization of bone. Congenital rickets may also be caused by other maternal diseases, including severe osteomalacia, untreated celiac disease, malabsorption, pre-eclampsia, and premature birth. Rickets in children is similar to osteoporosis in the elderly, with brittle bones. Pre-natal care includes checking vitamin levels and ensuring that any deficiencies are supplemented.

Also exclusively breast-fed infants may require rickets prevention by vitamin D supplementation or an increased exposure to sunlight.

In sunny countries such as Nigeria, South Africa, and Bangladesh, there is sufficient endogenous vitamin D due to exposure to the sun. However, the disease occurs among older toddlers and children in these countries, which in these circumstances is attributed to low dietary calcium intakes due to a mainly cereal-based diet.

Those at higher risk for developing rickets include:

  • Breast-fed infants whose mothers are not exposed to sunlight
  • Breast-fed infants who are not exposed to sunlight
  • Breast-fed babies who are exposed to little sunlight
  • Adolescents, in particular when undergoing the pubertal growth spurt
  • Any child whose diet does not contain enough vitamin D or calcium


Diseases causing soft bones in infants, like hypophosphatasia or hypophosphatemia can also lead to rickets.

Diagnosis & Tests

Rickets may be diagnosed with the help of:

  • Blood tests:Serum calcium may show low levels of calcium, serum phosphorus may be low, and serum alkaline phosphatase may be high from bones or changes in the shape or structure of the bones. This can show enlarged limbs and joints.
  • A bone density scan may be undertaken.
  • Radiography typically show widening of the zones of provisional calcification of the metaphyses secondary to unmineralized osteoid. Cupping, fraying, and splaying of metaphyses typically appears with growth and continued weight bearing. These changes are seen predominantly at sites of rapid growth, including the proximal humerus, distal radius, distal femur and both the proximal and the distal tibia. Therefore, a skeletal survey for rickets can be accomplished with anteroposterior radiographs of the knees, wrists, and ankles.

Prevention & Risk Factors

Prevention includes vitamin D supplements for exclusively breastfed babies. Treatment depends on the underlying cause. If due to a lack of vitamin D, treatment is usually with vitamin D and calcium. This generally results in improvements within a few weeks. Bone deformities may also improve over time. Occasionally surgery may be done to fix bone deformities. Genetic forms of the disease typically require specialized treatment.

Treatments & Therapies

The most common treatment of rickets is the use of vitamin D. However, surgery may be required to remove severe bone abnormalities.

Diet and sunlight
Treatment involves increasing dietary intake of calcium, phosphates and vitamin D. Exposure to ultraviolet B light (most easily obtained when the sun is highest in the sky), cod liver oil, halibut-liver oil, and viosterol are all sources of vitamin D.

A sufficient amount of ultraviolet B light in sunlight each day and adequate supplies of calcium and phosphorus in the diet can prevent rickets. Darker-skinned people need to be exposed longer to the ultraviolet rays. The replacement of vitamin D has been proven to correct rickets using these methods of ultraviolet light therapy and medicine.

Recommendations are for 400 international units (IU) of vitamin D a day for infants and children. Children who do not get adequate amounts of vitamin D are at increased risk of rickets. Vitamin D is essential for allowing the body to uptake calcium for use in proper bone calcification and maintenance.