Fang F, et al. - Considering the high prevalence of vitamin D deficiency among residents in Tianjin, China, researchers undertook the first large-scale study to investigate vitamin D status in this population. They also sought for the influencing factors. This study included 1814 participants, with mean serum 25(OH)D level of 49.44 ± 14.9 nmol/L. The optimal (50–125 nmol/L) 25(OH)D level was noted in only 47.63%. Outcomes thus suggested a high prevalence of vitamin D deficiency/inadequacy among Tianjin residents. Female participants, rural young adults, and elderly individuals particularly demonstrated vitamin D deficiency/inadequacy. Observations thus suggested the significance of vitamin D supplementation for these high-risk individuals.