1 Department of Medicine, Children's Hospital Medical Center, Boston, and the Department of Pediatrics, Lynn Hospital, Lynn Massachusetts
An example of rickets associated with anticonvulsant medication is described with onset at the age of 5 years 9 months. This patient had received anticonvulsant therapy since the age of 5 months. X-rays and serum values were normal up to age 3 years 2 months. Diagnosis of rickets at age 5 years 9 months was made by decreased serum calcium and phosphorus and elevated alkaline phosphatase plus characteristic x-ray findings. Other causes of rickets were excluded. Healing occurred with oral vitamin D: 10,000 units daily for two weeks, then 2,500 units daily for four weeks. Return of calcium and phosphorus to normal and early x-ray healing had occurred in six weeks. In six months complete healing by x-ray had occurred. Alkaline phosphatase level was persistently elevated, with both bone and liver fractions increased, but finally returned to normal when 50,000 units of oral vitamin D were given daily for 30 days. A plausible mechanism appears to be increased catabolism of vitamin D due to induction of hepatic microsomal enzymes when anticonvulsant medication is given.
Submitted on March 12, 1973