Rickets is a childhood bone disease in which growing bones fail to mineralize properly. Vitamin D deficiency is its most common cause worldwide, but not the only one, and any child with suspected rickets needs a doctor’s assessment. This article explains how vitamin D relates to rickets and its prevention. A vitamin D3 supplement is a way to prevent or correct a vitamin D deficiency. It is not a home treatment for suspected rickets and will not correct rickets caused by other conditions.
Quick Answer
Rickets develops when a child’s growing bones do not receive enough calcium and phosphate to mineralize normally. The most common cause is nutritional: too little vitamin D, too little dietary calcium, or both. Vitamin D helps the intestine absorb calcium and maintain phosphate balance, so deficiency can leave growth plates soft and bones weak. Preventive vitamin D, generally 400 IU a day in infancy, is widely recommended. Treatment of confirmed rickets uses doses higher than preventive ones, set and monitored by a doctor. Rare inherited forms, such as X-linked hypophosphataemia, do not respond to vitamin D alone.
What Rickets Means
Bones grow at areas of cartilage called growth plates, and new bone matrix must then be mineralized with calcium and phosphate to become hard. In rickets this mineralization is defective in children whose skeletons are still growing. The result is soft, weak bone that can bend under the child’s weight and growth plates that look widened on X-ray. The equivalent condition in adults, after growth has finished, is osteomalacia.
How Vitamin D Deficiency Leads to Rickets
When vitamin D is low, the gut absorbs less calcium. Blood calcium dips, parathyroid hormone rises to restore it, and this pulls calcium from bone and increases phosphate loss in the urine. Low phosphate and calcium together prevent normal bone mineralization. Low dietary calcium can cause the same problem even when vitamin D is adequate.
Signs and Symptoms
- Bowed legs or knock-knees in a child who is walking
- Widened wrists and ankles, or a beaded line along the ribs
- Delayed walking or other motor milestones
- A late-closing soft spot on the skull or delayed teething
- Bone pain, muscle weakness or frequent fractures
- Muscle spasms or seizures when blood calcium is low
Early rickets can be subtle or have no obvious signs, and some of these features have other causes. Mild bowing of the legs, for example, is common and normal in toddlers, so only a doctor can tell what is going on.
How Rickets Is Diagnosed
A doctor examines the child and usually arranges an X-ray of the wrist or knee, which shows widened or cupped growth plates. Blood tests commonly include calcium, phosphate, alkaline phosphatase, parathyroid hormone and 25-hydroxyvitamin D. Together, these help separate nutritional rickets from inherited and other forms, which need different treatment.
Who Is at Higher Risk
- Breastfed infants who do not receive vitamin D
- Children with darker skin, limited sun exposure or clothing that covers most of the body
- Children with low dietary calcium
- Premature infants and babies born to mothers with low vitamin D
- Children with malabsorption, chronic liver or kidney disease, or those on long-term anticonvulsant medicines
Prevention
The 2016 Global Consensus recommends 400 IU of vitamin D daily for all infants from birth to 12 months, and the recommended intake of 600 IU a day applies to children from age one, from food and supplements combined. Calcium-rich foods such as dairy products, calcium-fortified foods and some leafy vegetables support bone mineralization. Outdoor play with sun safety is healthy, but sunlight alone is not a dependable preventive measure, particularly for infants. Regular paediatric check-ups help pick up growth and feeding problems early.
Treatment
Treatment is directed by a doctor. It generally involves vitamin D at treatment doses well above preventive ones, together with enough dietary calcium, over several weeks to months, followed by a lower maintenance dose. Response is checked with blood tests and sometimes repeat X-rays. Do not treat suspected rickets at home with high-dose vitamin D, because the right dose depends on the child’s age and cause, and too much can raise blood calcium dangerously. Inherited and other forms of rickets need specialist treatment.
FAQs
Q. Can rickets be cured with vitamin D3 alone? Nutritional rickets from vitamin D deficiency usually improves with vitamin D and adequate calcium given under medical supervision. Inherited and other forms of rickets need different treatment.
Q. Is rickets still a problem today? Yes. Nutritional rickets still occurs around the world, including in sunny countries, particularly where vitamin D intake is low or dietary calcium is limited.
Q. My toddler has bowed legs. Should I start vitamin D? See a paediatrician first. Mild bowing is common in toddlers, and giving high-dose vitamin D without a diagnosis can be harmful.
Q. How can I lower my child’s risk? Give the vitamin D your paediatrician recommends, offer calcium-rich foods suited to your child’s age, encourage outdoor play with sun safety, and keep up regular check-ups.
