Rickets

Published by Bupa's Health Information Team, November 2010.

This factsheet is for parents of children with rickets, or who would like information about it.

Rickets is a disease that affects bone development in children. It causes their bones to become soft and weak, and can lead to bowed or curved bones. Rickets is usually caused by a lack of vitamin D and/or calcium.

About rickets

Bone development in children

During childhood, bones continually grow and develop. This growth is usually at its peak during infancy and puberty.

The strength of your child's bones depends on the amount of minerals laid down in the hard outer shell. This is done through a process called mineralisation. Minerals such as calcium and phosphorus are absorbed from the food your child eats and deposited in his or her bones. Your child also needs vitamin D for this process because it helps his or her body to absorb calcium and makes sure it gets to where it's needed (eg your child’s bones or teeth).

During childhood, mineralisation helps your bones to grow and develop, whereas in adulthood it maintains and repairs them.

Rickets

Rickets affects how your child's bones grow and develop. The bones don’t get enough of the minerals they need to grow, so they can become soft and weak. As your child grows, his or her increased body weight can cause the soft, weak bones to become bowed and misshapen.

Soft bones can also affect adults; this condition is called osteomalacia.

Symptoms of rickets

The symptoms of rickets may include:

• soft skull bones
• delayed closing of the soft spot at the top of your baby’s head (the anterior fontanelle)
• poor growth (your child may be short for his or her age)
• floppy limbs and body because of muscle disease or weakness
• teeth taking longer to come through
• weak tooth enamel that may lead to tooth decay
• bone pain in the arms, legs, spine and pelvis (although this is rare)
• fractures, as the result of a fall

If your child has severe rickets, he or she may also have low levels of calcium. This can cause muscle spasms.

Your child may also have problems such as:

• thickening of their ankles, wrists or knees (‘knock-knees’)
• legs that curve outwards (‘bow legs’)
• a breastbone that sticks out (‘pigeon chest’)
• ribs that stick out
• an asymmetrically shaped skull
• spinal deformities (for example, a hunched back)
• pelvic deformities

If your child has any of these symptoms or skeletal deformities, you should see your GP.

Complications of rickets

If your child has very low levels of calcium in his or her blood, he or she may develop hypocalcaemia. If left untreated, this can affect your child’s brain and cause confusion, memory loss, depression or hallucinations. The symptoms of extreme hypocalcaemia include:

• painful cramps
• muscle twitches
• tingling in hands and feet
• fits (convulsions)
• difficulty breathing (this is caused by spasms of the muscles of the throat)
• an abnormal heart rhythm

If your child has any of these symptoms, you should take him or her to see your GP as soon as possible.

Causes of rickets

Rickets is usually caused by a lack of vitamin D and/or calcium. Vitamin D is produced naturally by your body when your skin is exposed to sunlight and can also be obtained from some foods, such as oily fish. Calcium comes from your diet - dairy foods are a good source of calcium. Both calcium and vitamin D are essential for strong, healthy bones.

Rickets is more common in children from Asian, African–Caribbean and Middle Eastern origins because dark skin needs to be in the sun for much longer than fair skin to get enough vitamin D. However, children with fair skin can also be at risk if they don't go outside in the sunlight very often or are frequently covered up.

Children who have diets that cut out certain food groups (for example, the diet of vegetarians and vegans) may also be at risk of developing rickets. This is because they may not be getting enough calcium or vitamin D in their diet.

Hypophosphataemic rickets

This is a rare inherited form of rickets. If your child has this condition, he or she will be unable to absorb enough of phosphates or calcium needed to build strong, healthy bones.

Metabolic disorders

This is when your body can’t make energy properly from the food you eat, causing you to have too much or too little of the substances that keep you healthy. These can make it difficult for your child to process and absorb vitamin D, and can include vitamin D-dependent rickets type I (a rare inherited condition) or vitamin D-dependent rickets type II.

Secondary rickets

Rickets can also develop as a result of other conditions such as liver disease, kidney disease or kidney failure.

Diagnosis of rickets

Your GP will ask about your child's symptoms and examine him or her. He or she may also ask about your child's medical history.

If your GP thinks your child may have rickets, or she will arrange for your child to have a blood test. This will measure the amount of vitamin D, calcium and phosphorous in your child's blood. Your GP may also refer your child to a hospital for an X-ray, usually of the knee or wrist.

If your child is diagnosed with rickets, he or she will be referred to a paediatrician (a doctor who specialises in children’s health) for treatment and monitoring.

Treatment for rickets

Rickets is treated with daily vitamin D and calcium supplements. However, sometimes your child may be given a vitamin D injection once a year instead of daily vitamin D supplements.

It's important that you give your child the dose of supplements that your GP recommends. If your child has too much vitamin D, he or she may develop vitamin D toxicity, which causes an excess of calcium in the body (hypercalcaemia).

For hypophosphataemic rickets and vitamin D-dependent rickets, your child will have specialist treatment from a paediatrician.

If there are any other underlying conditions related to your child's rickets, such as a metabolic disorder or kidney disease, these will also need to be treated.

Special considerations

If you are pregnant or breastfeeding, it's important to make sure you get enough vitamin D. In the womb, your baby will get all the vitamin D he or she needs directly from you. This will be stored up in his or her body and used over the first few months after birth. After this, unless your baby gets vitamin D from another source, these stores will begin to run out.

Breast milk is the best source of nutrition for your baby. However, it contains very little vitamin D, so there is a risk that your baby may not get enough. If you are pregnant or breastfeeding, taking at least 10 micrograms of vitamin D supplements a day can reduce the risk of your baby developing rickets.

Prevention of rickets

There are several things you can do to help prevent your child from getting rickets.

Diet

Make sure your child eats plenty of foods that are rich in calcium and vitamin D. Good sources of calcium include:

• dairy products (for example, milk, yoghurt and cheese)
• bread made with fortified flour
• soya beans and tofu
• leafy green vegetables (for example, broccoli and cabbage but not spinach)

Diet alone isn't usually enough to give your child his or her daily requirement of vitamin D. However, you can get some vitamin D from:

• oily fish (for example, sardines and mackerel)
• eggs (cooked, not raw)
• margarine
• breakfast cereals fortified with vitamin D

Sun

Vitamin D is produced naturally by your body when your skin is exposed to sunlight, so your child may get enough vitamin D during summer by spending some time in the sun. However, a child’s skin can be easily damaged by the sun, so it’s very important not to let your child’s skin burn. For most children, spending frequent short spells in the sun without wearing sunscreen (typically a few minutes in the middle of the day) will be enough for them to get the vitamin D they need. However, for longer periods, you will need to protect your child’s skin from burning. This means keeping them in the shade, covering them up and applying sunscreen to their skin when exposed.

You need to be more careful with babies and toddlers, as they have very sensitive skin and can burn easily. Always keep babies and toddlers in the shade, or cover them up.

Supplements

The Department of Health recommends that all children aged six months to five years should take supplements containing seven micrograms of vitamin D a day, unless they drink 500 ml (one pint) or more of formula milk a day. This is especially important for babies being breastfed or children in at risk groups (for example Asian, African–Caribbean and Middle Eastern). Women who are pregnant or breastfeeding should take 10 micrograms a day.

Some families may be eligible for free vitamin D supplements from the government-run Welfare Foods Scheme.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.