Cod: 1574 VITAMIN D STATUS IN A TURKISH POPULATION: A RETROSPECTIVE STUDY M. Agilli 1 , E.O. Akgul 4 , I. Sener 4 , F.N. Aydin 3 , I. Aydin 2 , H. Yaman 4 1 Department of Biochemistry, Agri Military Hospital, Agri, Turkey 2 Department of Biochemistry, Sarikamis Military Hospital, Sarikamis, Turkey 3 Department of Biochemistry, Sirnak Military Hospital, Sirnak, Turkey 4 Department of Medical Biochemistry, Gulhane Military Medical Academy, Ankara, Turkey BACKGROUND: Recent studies have reported lower vitamin D levels than expected in different sex and age groups in developing countries. In the present study, we investigated vitamin D status and relationship between age and sex groups among a Turkish population. METHODS: Serum 25-OH Vitamin D3 [25(OH)D3] levels measured in 13429 individuals (4641 males and 8788 females) aged between 1-95 with an ion-exchange HPLC method with UV dedector. Data were collected retrospectively from outpatients via laboratory information system of Gulhane Military Medical Academy (Ankara, Turkey), between January 2007 – December 2011. The values that exceeded ±4 SD were excluded. All variables were tested for normality using the Kolmogorov-Smirnov test. Statistical analysis was performed using Medcalc Ver 9.2.01 (MedCalc Software, Ostend, Belgium). RESULTS: The mean serum 25(OH)D3 concentrations in summer were 25.9 ± 12.7 and 23.2 ± 13.6 ng/mL for males and females, respectively. They were 23.0 ± 12.1 and 21.5 ± 13. ng/mL in winter for males and females, respectively. Reference intervals in summer were 6.55 – 55.2 and 6.05 – 56.0 ng/mL for males and females, respectively. They were 6.20 – 50.5 and 5.90 – 55.6 ng/mL in winter for males and females, respectively. Our current reference interval (RI) for 25(OH)D3 is 11-70 ng/Ml in our laboratory. CONCLUSIONS: For all groups, RI limits were lower than current values which were in use in our laboratory. Our study results indicate that vitamin D deficiency is a highly prevalent condition in a Turkish population and could be a matter of concern for public health authorities. Poster Abstracts – IFCC WorldLab Istanbul 2014 – Istanbul, 22-26 June 2014 • DOI 10.1515/cclm-2014-4060 Clin Chem Lab Med 2014; 52, Special Suppl, pp S1 – S1760, June 2014 • Copyright © by Walter de Gruyter • Berlin • Boston S1713 Vitamins and nutrition