Kids Health Info

Rickets

  • Rickets is a preventable bone disease that causes soft bones.  Rickets only occurs when children are growing - if a child has softer bones, the bones can bend and become an abnormal shape. 

    Signs and symptoms 

    Children with rickets may have:

    • Legs that are an abnormal shape - 'bow legs' or 'knock knees' or legs that are not straight. It is normal to have some bowing before two years old and some knock-knees around the age of four.
    • Swelling at the wrists, knees and ankles because the ends of the bones are larger than normal.
    • Late teeth and problems with tooth enamel.
    • Late closure of the anterior (front) fontanelle (the soft part on top of a baby's head).
    • Poor growth.
    • Late crawling and walking.
    • Bone fractures after minor falls or traumas.

    Infants and children with rickets are often grumpy and irritable because their bones are sore. Sometimes babies with rickets can have symptoms of very low calcium levels, such as muscle cramps or seizures. Seizures from low calcium mostly happen in babies who are less than one year old.

    Who is at risk?

    Rickets is not common. Nearly all cases of rickets in Australia occur in infants and children who have migrated to Australia, or whose parents migrated to Australia. Rickets is more common when children are growing quickly.  It mostly occurs in infants and young children, but it can also occur in teenagers. The risk factors for rickets are the same as the risk factors for low vitamin D. Rickets is a disease of childhood (the term 'children' is used to refer to infants, children and adolescents).

    Who is at risk of low vitamin D (and rickets)?

    • Children with very dark skin - the colour in skin (melanin) acts as a natural sunscreen and increases the time people need to make vitamin D.
    • Children who do not expose their skin to sun - people who stay inside or who wear clothing that covers most of their body.
    • Children with conditions affecting how the body controls vitamin D levels - for example, liver disease, kidney disease, and problems with absorbing food (cystic fibrosis, coeliac disease, inflammatory bowel disease).  Some medicines, such as anticonvulsants or isoniazid, can affect vitamin D levels.
    • Breastfed babies who also have other risk factors - breastmilk is the best type of food for babies, but it does not contain much vitamin D. Newborn babies get their store of Vitamin D from their mothers, so they are at risk of low vitamin D if their mother has low vitamin D and/or if they have dark skin.

    Not all children with low vitamin D get rickets. Rickets is more likely in babies and children who also have low dairy intake, and in babies that breastfeed for a long time without starting solid foods at the normal age (around four to six months).

    Causes

    Rickets is usually caused by low vitamin D, especially if children also have low calcium or low phosphate levels. Calcium and phosphate are minerals that are mostly found in milk and dairy foods. Sometimes kidney problems cause rickets by affecting how the body handles vitamin D, calcium and phosphate.

    Prevention

    Rickets can be prevented by: 

    • Making sure women have good vitamin D levels during pregnancy.
    • Identifying babies who are at risk of low vitamin D (fully breastfed babies with at least one other risk factor such as dark skin) and starting vitamin D (400 IU daily) from birth and continuing until they are at least one year old.
    • Introducing solid foods for babies when they are four to six months old.
    • Including enough calcium and phosphate in children's and adolescents' diets - they need two to three serves of dairy each day (one serve of dairy is: one glass of milk or one tub of yoghurt or one slice of cheese).
    • Identifying and treating low vitamin D.
    • Spending time outside to prevent low vitamin D (see the Kids Health Info factsheet: Vitamin D). Children with dark skin who live in the southern parts of Australia may need extra vitamin D supplements during winter.

    Spending some time in the sunshine every day and including foods with vitamin D and calcium in your child's diet helps prevent rickets. However, foods only provide a small amount (10-25 per cent) of daily vitamin D needs for most people in Australia.   If your child has fair skin, about 20 minutes of sunshine either early in the morning or late in the afternoon is enough for them to get plenty of vitamin D. If your child has darker skin, they will need more time in the sun as their skin does not absorb the sunlight as quickly. It is still important for people with fair to olive skin to use sunscreen and follow skin cancer prevention advice. 

    Treatment

    • Children with rickets (and those with low calcium) need to see a specialist urgently.
    • They will need blood tests (to check vitamin D, calcium balance, phosphate, kidney function, and bone turnover), urine tests, photos and X-rays.
    • Children with very low calcium (including children with seizures) will need admission to hospital to have extra calcium and heart monitoring (low calcium levels can affect the heart rhythm).
    • Rickets caused by low vitamin D is treated by vitamin D supplements. Often children will need extra calcium and phosphate as well, by increasing dairy foods or by taking supplements.
    • Vitamin D tablets or mixtures can be low dose (taken daily) or high dose (taken monthly or less often). It is important to check calcium balance first - sometimes children will need extra calcium and/or phosphate before they have high doses of vitamin D.
    • Rickets caused by kidney problems is managed by the renal (kidney) doctors.

    Follow-up

    • Regular follow up with a paediatrician is needed to ensure healthly levels of vitamin D, calcuim and phosphate are maintained.
    • Blood tests to measure vitamin D levels will be done periodically.
    • X-rays to look at bone growth will be done at regular intervals.
    • A review by a dietitian will help to ensure that your child's diet contains all the right food groups.

    Key points to remember

    • Rickets is a disease where bones are weak and soft.
    • It is caused by not having enough vitamin D.
    • It can be prevented and treated by having daily sun exposure without sunscreen and by eating foods that contain vitamin D.

    More information

     

    Developed by the RCH Departments of General Medicine, Dietetics, and Gastroenterology. First published in Feb 2007. Updated January 2014.



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Disclaimer
This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital, Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.