There are three main causes of rickets:
- lack of vitmin D or calcium,
- genetic defect, and
- underlying disease.
Lack of vitamin D and calcium
Rickets is most commonly caused by a lack of vitamin D or calcium in your child’s diet. Both of these minerals are essential for a child to form strong and healthy bones.
Vitamin D comes from two main sources:
- 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 some foods, such as oily fish, eggs and fortified breakfast cereals.
A deficiency of vitamin D over a long period of time causes rickets in children and osteomalacia (soft bones) in adults.
Rickets is more common in children from Asian, African Caribbean and Middle Eastern origin because their skin is darker and needs more sunlight to get enough vitamin D. However, any child that does not go outside very often, is frequently covered up or has a diet low in vitamin D or calcium can also be at risk.
Genetic defect
There are also rare forms of rickets that can be inherited.
Hypophosphataemic rickets involves a genetic defect that causes abnormalities in the way the kidneys and bones deal with phosphate. This leaves too little phosphate in the blood and bones which leads to weak and soft bones.
The abnormal gene is on one of the sex chromosomes (the X chromosome). If a mother (with 2 X chromosomes) had a faulty gene she can pass it on to both her sons and daughters; a father (who has one X and one Y chromosome) with the faulty gene can only pass it on to a son.
Other genetic forms of rickets affect the special proteins in the body that vitamin D works with.
Underlying disease
Rickets occasionally develops in children with rare forms of kidney, liver and gut diseases that affect the absorption and metabolism of vitamins and minerals.
