Evaluation of the deficiency status of 25‐hydroxyvitamin D and associated factors in Southwest China: A hospital‐based retrospective cross‐sectional analysis of a low‐latitude, high‐altitude, multiracial region

Vitamin D deficiency is widespread in different populations and regions worldwide and has become a global health issue. The vitamin D status of the population in the Yunnan Province of Southwest China has not been evaluated to date. Therefore, in this study, we evaluated the vitamin D status according to the serum concentrations of 25‐hydroxyvitamin D (25(OH)D) in individuals of Yunnan Province, a low‐latitude, high‐altitude and multiracial region in China. The data on 25(OH)D concentrations from October 2012 to December 2017 were retrospectively collected and assessed using the laboratory information system from 52 950 hospital‐based participants (age, 1 day–96 years; females, 73.74%). The serum concentration of 25(OH)D was evaluated using a chemiluminescent immunoassay. The analysis was stratified by sex, age, sampling season, testing year, minority, residential district, latitude, altitude and meteorological factors. Vitamin D status was classified as follows: severe deficiency: