Abstract: Objective To explore the association of serum 25- （OH） vitamin D level with age,gender and seasons in 5 181 persons of Shandong province. Methods Serum samples were collected from the hospital from 2014 to 2017,and the serum 25- （OH） vitamin D was detected by electrochemiluminescence. All of the subjects were grouped based on age,gender,and the seasons of sampling for analyses of vitamin D. Results Males had a significantly higher level（17.11±11.75 ng/mL） of vitamin D than females （15.08±11.73 ng/mL） （P<0.01）. The vitamin D level in Children of age of 0~9 （26.99±17.28 ng/mL） was strikingly elevated （P<0.01） but no significant difference was noted among the other groups（P>0.05）. The vitamin D level in all subjects varied in seasons,showing the highest in the summer and the lowest in the winter （P<0.01）. Conclusion The vitamin D level varies in genders,ages and seasons,suggesting a deficiency of vitamin D nutrient in the local people of Shangdong.

Key words: Shandong Province, Vitamin D, Gender, Age, Season, Electrochemiluminescence