Rickets: Soft, Weak Bones in Children

Rickets causes soft, weak bones in children. It usually happens when a child does not get enough vitamin D, which helps growing bones absorb the minerals calcium and phosphorus. It can also happen when calcium or phosphorus levels are too low. Rickets is rare in the United States.

Why a child may not get enough vitamin D

A child may fall short of vitamin D if they:

• have dark skin;
• spend too little time outdoors;
• wear sunscreen all the time outdoors;
• don't eat foods with vitamin D, because of lactose intolerance or a strict vegetarian diet;
• are breastfed without vitamin D supplements;
• cannot make or use vitamin D because of a medical disorder such as celiac disease.

The inherited form

Besides rickets caused by diet, children can inherit a form of the disease. In one inherited condition, X-linked hypophosphatemia, blood phosphate is low. Phosphate is essential for developing bones and teeth, and without enough of it bones can weaken or soften — rickets in growing children, and a similar condition, osteomalacia, in adults. Its effects vary widely, even within a family: mildly affected people may have low phosphate and nothing else, while more severely affected children often grow slowly and develop bone problems such as bowed legs, which can impair movement, cause pain and tend to worsen over time.

Symptoms

• Bone pain or tenderness.
• Impaired growth.
• Deformities of the bones and teeth.

Diagnosis and treatment

A child's doctor uses laboratory and imaging tests to diagnose rickets. Treatment replaces the calcium, phosphorus or vitamin D missing from the diet.

Sources

• MedlinePlus, U.S. National Library of Medicine, "Rickets." https://medlineplus.gov/rickets.html
• MedlinePlus Genetics, "X-linked hypophosphatemia," used for the inherited form: https://medlineplus.gov/genetics/condition/x-linked-hypophosphatemia/
• Rewritten in hubnx's own words.