Masking of vitamin d-deficiency osteomalacia by concurrent thyrotoxicosis

Despite their world-wide prevalence, the concurrent association of osteomalacia due to vitamin D deficiency and thyrotoxicosis has not been previously reported. We describe the diagnostic perplexity derived from this rare combination in a patient in whom increased bone turn-over due to thyrotoxicosis resulted in normalization of serum calcium, masking the characteristic hypocalcemia of vitamin D deficiency. Department of Medicine (Y.L., L.A.) and Endocrine Unit (Y.L.), Soroka University Hospital of Kupat-Holim and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.