Vitamin D deficiency in white, apparently healthy, free-living adults in a temperate region.

Objective: The precise incidence of vitamin D deficiency is not known, primarily because there is no consensus on the optimal levels of serum 25(OH)Vitamin D. The aim of the present study was to determine the incidence of vitamin D deficiency in a large group of normal adult volunteers residing in a typical temperate region. DESIGN-METHODS: In 625 healthy, free living adults (553 women, 72 men, aged 18-85 years), serum 25(OH)Vitamin D and 1-25(OH)2 Vitamin D (RIA), plasma intact PTH (ECLIA) and routine chemistries (multianalyser) were determined at baseline once during a whole year.