THU399 Increasing Testing And Use Of Vitamin D Supplements Leads To Slow Progress In Restoring Vitamin D Adequacy: An Interim Analysis Of The "Vitamin D Deficiency In Western Greece" Real World Data Study

Abstract Disclosure: R.D. Paparodis: None. D. Bantouna: None. E. Karvounis: None. S. Livadas: None. N.G. Angelopoulos: None. I. Zoupas: None. S. Imam: None. J.C. Jaume: None. Introduction: Vitamin D testing and use of supplements (VDS) has been rising constantly worldwide in the past years. Despite the ample use of resources, clinical observations suggest that the vast majority of the population remains in the deficiency range (VDD). We designed the present real world data study, to assess this paradox. Methods: We reviewed data from all patients attending our clinics between Mar-2014 and Dec-2022. We recorded the patients' gender, age, history of VDS use, duration and dose, and vitamin D measurements within 2 months from the clinic visit, when available. We assessed the percentage of patients reaching vitamin D adequacy (>30ng/ml) (VDA) by year and month of testing, by the use of VDS: in low dose (≤1200IU daily) (LD), medium dose (1201-3000IU daily) (MD) and high dose (>3000IU daily) (HD), by duration of use: short use (<12 months) and long term (≥12 months) (LT), by the timing of use: current use (CU), former use (stopped at least 2 months) (FU) and never use (NU). Results: We reviewed the charts of 10,102 consecutive patients, age 44.3±17.0 years, n=7691 females (76.1%) and n=2411 males (23.9%). Data on VDS use were available in n=8605 patients (85.2%): NU n=7212 (71.4%), FU n=5.6% and CU n=827 (8.2%). Vitamin D measurements were available in n=6912 patients (68.4%); NU n=5644 (81.7%), FU n=507 (7.3%) and CU n=761 (11.0%). Vitamin D testing was available in 42.1% of patients in 2014 and rose to 86.8% of patients in 2022, p<0.001. The population's mean vitamin D concentration was 23.1±9.1ng/ml. VDD was present in n=5401 (78.1%) and VDA in n=1511 (21.9%). VDD was present in 55.2% of CU, 76.8% of FU and 84.5% of NU (p<0.001). The rate of VDD decreased with the dose of VDS used both in FU (LD 83.9%, MD 78.8% and HD 73.0%, p<0.05) and CU (LD 60.1%, MD 53.2% and HD 51.9%, p<0.05). The rate of VDD was lowest in August (62.1%) and September (61.2%), but remained >70% in October and >80% during the remaining months of the year, p<0.001. Any use of VDS rose from 2.9% in 2014 to 35.2% in 2022 (p<0.001), and the VDD rate declined from 85.2% in 2014, to 74.5% in 2022. The mean vitamin D concentration rose from 21.7±9.0ng/ml in 2014 to 25.0±10.3ng/ml in 2022, p<0.001. Longer duration of VDS use decreased the risk of VDD (LT vs ST use OR 0.51, 95%CI 0.38-0.69, p<0.0001). LT use of VDS in HD produced the lowest risk (30.2%), while ST and LT use of VDS in LD produced the highest risk of VDD (81.6% and 83.3% respectively). Conclusions: Despite a continuous, significant rise in vitamin D testing, and VDS use, the majority of patients remain deficient. The only strategy that appears somewhat effective in reducing VDD is the prolonged use of VDS, and even in that scenario, it loses efficacy a few months after VDS discontinuation. New strategies are required if we are to solve this world health issue. Presentation: Thursday, June 15, 2023