Vitamin D deficiency of unknown etiology

Abstract

We report on a 68 year old Caucasian male who was referred to our Metabolic Clinic with a very low 25 hydroxy-vitamin D (25(OH)D) level of 4.0 ng/ml. History did not reveal any medications know to interfere with 25(OH)D metabolism or history of bone pains or weakness and clinical examination did not reveal myopathy. Relevant laboratory testing confirmed the low 25(OH)D with hypocalcinuria. All other laboratory tests were essentially normal. He was started on oral Vitamin D supplementation and had an excellent response with his most recent level at 35.1 ng/ml. Since we could not find an obvious cause for his Vitamin D deficiency we speculate that it is possibly due to his obesity and suggest that obese persons be screened for Vitamin D deficiency.