Bilateral Femoral Fracture in an Adolescent Male Due to Severe Vitamin D Deficiency

Purpose/background: Mild to moderate vitamin D deficiency is common in pediatric patients in the U.S. Severe hypovitaminosis D has been linked to specific risk factors, such as female gender, obesity, winter season, darker skin, lack of exposure to the sun, and low vitamin D intake. It has been reported that adolescents usually experience less severe clinical symptoms than young children with vitamin D deficiency. We present a previously healthy 15-year-old Caucasian male with bilateral spontaneous femoral fracture due to severe hypovitaminosis rickets. He had unusual eating habits such as avoiding dairy, vegetables, and fruits. In addition to always preferring to eat alone due to anxiety. Patient is underweight with a BMI z score of -4.05 at time of presentation. Due to lack of interest in physical activities, the patient spent most of his time indoors.

Design/methods: This is a case report of a patient who presented to the children's hospital for further workup for bilateral spontaneous femoral fractures.

Findings/results: Laboratory work up revealed that his 25 hydoxy-vitamin D level was less than 4 ng/ml, calcium level was 5.7 mg/dl (8.4-10.5mg/dL), and phosphorus was 3.5 mg/dl (3.7-4.7 mg/dl). His intact parathyroid hormone was elevated at 555 pg/ml (14-95 pg/ml) and alkaline phosphatase was elevated at 777 U/L (91-339 U/L). A wrist x-ray showed widening of the distal radial and ulnar metaphyses with metaphyseal cupping. Further labs showed macrocytic anemia and severe vitamin B12 deficiency. Workup for malabsorption was negative. Patient underwent bilateral open hip reduction internal fixation. Hypovitaminosis D and hypocalcemia were treated with calcium carbonate and oral vitamin D3 supplements. His follow up laboratory evaluation showed normalization of his calcium, phosphorus, PTH, alkaline phosphatase, and vitamin D levels. Repeat wrist X-ray two months later revealed marked improvement in the appearance of the distal radial and ulnar growth plates and metaphyseal regions.

Conclusions: This patient's vitamin D deficiency/rickets was found to be secondary to malnutrition due to limited intake, along with limited sunlight exposure. We recommend that a detailed dietary history is obtained in every adolescent patient to evaluate for proper vitamin D intake, especially in patients who are significantly underweight. If vitamin D deficiency is expected, vitamin D level should be checked and appropriate treatment should be initiated once vitamin D insufficiency is confirmed.