Rickets: symptoms, causes and treatment in children

The NHS says the main symptom of rickets is bowed legs. Other symptoms of rickets in children include swollen, painful wrists, pain in the back, shoulders, ribs, pelvis or legs, changes in the way the child walks or reluctance to walk, tiredness when walking, weak muscles causing difficulty with stairs, tingling, cramping or twitching of muscles, and breaking bones more often or after a minor accident. Children may be small for their age and their teeth may come through late.

NICE CKS adds that rickets may present with progressive leg deformity, painful wrist or rib swelling, craniotabes (soft areas of the skull) and impaired growth. Low calcium may cause irritability, tetany or seizures, so a child with muscle twitching or fits needs prompt assessment.

• Bowed legs or a changed walking pattern.

• Swollen, painful wrists or bone pain.

• Poor growth, or delayed first teeth.

• More fractures than expected, or fractures after minor bumps.

• Muscle cramps, twitching or, rarely, seizures from low calcium.

Bones need calcium and phosphate to harden. Vitamin D helps the body regulate those minerals, so too little vitamin D leaves growing bones soft. The NHS says a lack of vitamin D can lead to bone deformities such as rickets in children, and that rickets is usually caused by low vitamin D or calcium. NICE Clinical Knowledge Summaries (CKS) describes vitamin D as vital for musculoskeletal health.

The NHS notes that in adults the equivalent is called osteomalacia.

NICE CKS says that in the UK, 80 to 90% of vitamin D comes from skin exposure to ultraviolet B light in sunlight and 10 to 20% from food. Risk factors in children include low or no sun exposure, darker skin pigmentation, being an exclusively breastfed baby from birth, being over 6 months and taking less than 500 mL of formula a day, a malabsorption disorder, severe liver disease or end-stage kidney disease, certain medicines and obesity.

The NHS says calcium is found in milk, cheese, yoghurt and green leafy vegetables, and that a child may not get enough without a healthy, balanced diet. If symptoms are caused by another condition, treating that condition will help. The NHS notes that vitamin D is made in the skin from summer sunlight, and that this is not enough between September and March.

The NHS lists treatment as vitamin D and calcium supplements, a healthy balanced diet, and spending more time outside with the sun on the skin. It advises spending time in the shade when the sun is at its strongest, which in the UK is between 11am and 3pm from late March to September.

NICE CKS describes management as a fixed loading dose of vitamin D followed by a maintenance dose, assessment of dietary calcium and the need for supplements, advice on safe sunlight and dietary sources, and follow-up to recheck vitamin D and the bone profile. It advises seeking specialist advice or referral if there are clinical features of rickets or low calcium. Dosing is for the treating clinician: do not give a child high-dose supplements without advice.

If rickets has caused bone problems such as bowed legs, the NHS says further treatment may be needed, and some people may need surgery.

Rickets is a condition of growing bones, so it is a children's condition; the equivalent in adults is called osteomalacia. The NHS says children with rickets may be small for their age and their teeth may come through later than usual.

NICE Clinical Knowledge Summaries lists children at higher risk of vitamin D deficiency: those with low or no exposure to the sun, darker skin pigmentation, exclusively breastfed babies from birth, infants over 6 months taking less than 500 mL of formula milk a day, and children with a malabsorption disorder, severe liver or end-stage kidney disease, who take certain drugs, or have obesity.

It says vitamin D deficiency in children may present as rickets, with progressive leg deformity, painful wrist or rib swelling, soft areas of the skull (craniotabes) and impaired growth, and may also cause low calcium, with irritability, muscle spasm (tetany) or seizures. A child with muscle twitching or fits needs prompt medical assessment.

No. The NHS describes rickets as usually caused by not getting enough vitamin D or calcium, and NICE Clinical Knowledge Summaries lists risk factors such as low sun exposure, skin pigmentation, feeding pattern, malabsorption and medicines. None of these describe an infection that can spread between children.

Siblings or family members may share risk factors, such as diet or limited sun exposure, so if one child is diagnosed it is sensible to ask your GP or health visitor whether others in the family need vitamin D advice.

The NHS says our bodies make vitamin D when the skin is exposed to summer sunlight, but that we cannot make enough from sunlight between September and March. Calcium is found in milk, cheese, yoghurt and green leafy vegetables, and children may not get enough without a healthy, balanced diet. The NHS vitamin D page lists oily fish, red meat, egg yolks and fortified foods as dietary sources of vitamin D, and says cows' milk is generally not a good source in the UK because it is not fortified.

The NHS advises getting outside without sunscreen for 15 minutes 2 or 3 times a week between late March and September, which may need to be more often with brown or black skin, and spending time in the shade when the sun is at its strongest, between 11am and 3pm in the UK from late March to September.

The NHS says a GP who suspects rickets will check vitamin D and calcium levels, which may include blood tests and a urine sample, and may refer the child to a specialist for X-rays or bone scans. NICE CKS says vitamin D levels are measured as serum 25-hydroxyvitamin D. In UK terms a level below 25 nmol/L carries an increased risk of deficiency, a level of 25 to 50 nmol/L may be inadequate, and above 50 nmol/L is sufficient for most people.

NICE CKS advises assessment if a child has musculoskeletal symptoms that could be due to rickets or osteomalacia, abnormal bone blood results or X-ray findings, or known bone disease where correcting vitamin D is needed before other treatment.

The NHS says you can prevent rickets by making sure you get enough vitamin D and calcium. It advises giving a baby vitamin D drops from birth if they are exclusively breastfed or are under 6 months and have less than 500ml of formula a day, taking a vitamin D supplement (especially if you are over 65, or pregnant or breastfeeding), eating a healthy, balanced diet, and getting outside in the sun without sunscreen for short periods between late March and September.

The NHS also says some families can get free vitamin supplements for children through the Healthy Start scheme. NICE Clinical Knowledge Summaries advises vitamin D drops for children from birth to 4 years, and considering supplements for all other children, including those at high risk of deficiency. The NHS warns that taking too much vitamin D over a long time can cause too much calcium to build up in the body, so follow the dose advised for your child.

The NHS vitamin D page carries an older review date, so check the current dose with a pharmacist, health visitor or GP.

The NHS advises seeing a GP if you think you or your child might have rickets. At the appointment the GP will check vitamin D and calcium levels, which may include blood tests and a urine sample, and may refer to a specialist for tests such as X-rays and bone scans.

NICE Clinical Knowledge Summaries advises seeking specialist advice or arranging referral if there are clinical features of rickets or low calcium. Muscle twitching, spasms or a seizure in a child need prompt assessment: use NHS 111, or call 999 for a seizure, as for any child who has a fit.

On the NHS, a GP or health visitor is the usual first step, with referral to a paediatrician or specialist if rickets is suspected. Supplements are available to buy, and the NHS says some families qualify for free vitamins through Healthy Start.

Some families choose to see a private paediatrician or endocrinologist for tests and review. The same principles apply, and if you do, share results with your NHS GP so that supplement doses and follow-up blood tests stay coordinated.