Standard Definition of Vitamin D Deficiency Is Challenged

Although many afflictions have been attributed to vitamin D deficiency, bone disease (i.e., osteomalacia) is the clinical entity with the strongest causal link to vitamin D deficiency. In this study, Australian researchers sought to identify the 25-hydroxyvitamin D (25[OH]D) level below which abnormal bone physiology becomes evident. Data were obtained from a large cohort of 12,000 adults and from a smaller cohort of 150 adults who underwent more extensive testing. Patients with hypercalcemia or renal disease were excluded.

Across 25(OH)D levels ranging from 12 to 60 ng/mL (30 to 150 nmol/L), there was a weak inverse relation between 25(OH)D and serum parathyroid hormone (PTH), and a weak positive relation between 25(OH)D and serum calcium. …