Rickets

What is rickets?

Rickets is a bone disease that affects infants and young children. The child’s growing bones fail to develop properly due to a lack of vitamin D. This can result in soft and weakened bones, fractures, bone and muscle pain, and bony deformities. You can help protect your child from the effects of rickets by understanding the risk factors for vitamin D deficiency and taking steps to prevent it.

Although rare, rickets is on the increase among Australian children. Most cases of rickets in Australia occur due to low levels of vitamin D. Overuse of sun protection, due to increased concerns about skin cancer risks, may be one reason for the increasing rates.

If you think your child has rickets or is at risk of vitamin D deficiency, it is important to consult your GP (doctor) or health care provider. They can help you decide on an appropriate treatment plan for your child.

Symptoms of rickets

Signs and symptoms of rickets can include:

• painful bones, muscle weakness, cramps and spasms
• slowed growth and development
• increased risk of broken bones, including spontaneous breaks that occur by themselves without pressure or trauma
• dental problems such as teeth failing to form or being slow to emerge, deformed teeth or soft tooth enamel
• prominent forehead and a large front fontanelle (soft spot) in infants
• deformities of the skeleton such as bowed legs, kyphosis (‘hunch-back’), scoliosis (sideways curves of the spine), outward jutting breastbone or abnormal skull shape.

Who is at risk of developing rickets?

In Australia, rickets occurs most frequently in recently arrived migrant, asylum seeker and refugee children, as well as in those whose parents migrated to Australia.

Children may be at increased risk of developing rickets due to vitamin D deficiency if they:

• have naturally very dark skin (which tends to absorb less sunlight than lighter skin)
• are born to women with a vitamin D deficiency
• cover most of their body for religious or cultural reasons
• are sick, have a disability or are unable to spend time outdoors for other reasons
• never go outside without sunscreen
• have a medical condition, such as
  • certain bowel diseases
  • disorders of the intestine, liver or kidneys that prevent the body from absorbing vitamin D or converting it into its active form
  • disorders that reduce digestion or absorption of fats, as vitamin D is a fat-soluble vitamin
• have a lack of vitamin D or calcium in their diet.

The role of vitamin D

Our body needs vitamin D to help it absorb calcium and phosphorus. These minerals are essential for the growth and development of strong, healthy bones. Lack of vitamin D reduces the body’s ability to control the levels of these vital minerals and increases a child’s risk of developing rickets.

About 90 per cent of our vitamin D comes from exposure to the sun. When direct sunlight hits our skin, the ultraviolet radiation converts a skin substance called 7-dehydrocholesterol into vitamin D. There are also very small amounts of vitamin D in some foods. However, food sources alone are usually not enough to maintain the levels of vitamin D that our body needs.

Once vitamin D is made in the skin or absorbed from food through the intestine, it is changed into its active form – a hormone – by the liver and kidneys. It is then available to help our body build strong bones and teeth, through the process of ‘mineralisation’.

Sun exposure

UV radiation levels vary depending on location, time of year, time of day, cloud coverage and the environment. Babies and young children are particularly vulnerable to UV exposure damage and should always be well protected whenever UV radiation levels reach 3 or above. Physical sun protection measures such as dense shade, cool, covering clothing and wide-brimmed hats are recommended. For infants 6 months and older, apply a sensitive sunscreen to those small areas of exposed skin not protected by clothing or hats.

Preventing rickets

Rickets can often be prevented through preventing or treating low vitamin D levels, in addition to maintaining sufficient dietary intake of calcium and phosphate. See the Vitamin D fact sheet for more information.

Diagnosis of rickets

Rickets may be diagnosed using a number of tests including:

• physical examination
• blood tests
• long bone x-rays
• bone scans.

Treatment of rickets

Treatment options for rickets include:

• improved sunlight exposure
• improved diet that includes adequate intake of calcium and vitamin D
• oral vitamin D supplements – these may need to be taken for about 3 months
• special forms of vitamin D supplements – for people whose bodies can’t convert vitamin D into its active form
• treatment for any underlying disorder
• surgery to correct severe bone deformities.

Bones that are poorly mineralised generally respond very quickly to dietary supplementation with calcium and vitamin D. Improvements may be seen on x-ray after only a few days of treatment.

If rickets is treated when the child is young, there is a good chance that the skeletal deformities will disappear as the child matures. However, the deformities and reduced height will be permanent if the child goes through puberty without treatment.

Where to get help

• Your GP (doctor)
• Maternal and Child Health Line (24 hours) Tel. 13 22 29
• Paediatrician
• Dietitians Australia Tel. 1800 812 942
• NURSE-ON-CALL (24 hours, 7 days) Tel. 1300 60 60 24 – for expert health information and advice