Rickets usually occurs because of a lack of vitamin D or calcium. It can also be caused by a genetic defect or another health condition.
Lack of vitamin D and calcium
The most common cause of rickets is a lack of vitamin D or calcium in a child’s diet. Both are essential for children to develop strong and healthy bones. The main sources of vitamin D are:
- Sunlight – your skin produces vitamin D when it is exposed to the sun. We get most of our vitamin D this way.
- Food – vitamin D is also found in foods such as oily fish, eggs and fortified breakfast cereals.
Over a long time, vitamin D deficiency causes rickets in children and osteomalacia (soft bones) in adults.
Rickets is more common in children of Asian, African-Caribbean and Middle Eastern origin because their skin is darker and needs more sunlight to get enough vitamin D. However, any child who does not get enough sunlight, is frequently covered up or has a diet low in vitamin D or calcium is also at risk of getting rickets.
Babies born prematurely are also at risk of developing rickets because the foetus builds up stores of vitamin D while in the womb. As the amount of vitamin D in breast milk varies, the Department of Health recommends that all pregnant and breastfeeding women should take a daily supplement of 10 micrograms (mcg) of vitamin D.
This ensures that the mother’s vitamin D requirements are met and that adequate foetal stores are built up for early infancy.
Genetic defect
Rare forms of rickets can also be inherited (passed on from a parent to a child).
Hypophosphatemic rickets is a genetic disorder in which the kidneys and bones deal abnormally with phosphate (calcium phosphate is what makes bones and teeth hard). This leaves too little phosphate in the blood and bones, leading to weak and soft bones.
Other types of genetic rickets affect special proteins in the body that are used by vitamin D.
Underlying conditions
Occasionally, rickets develops in children with rare forms of kidney, liver and intestinal conditions. These can affect the absorption and metabolism of vitamins and minerals.
