PSAT173 Evaluation of efficacy and safety of different doses of cholecalciferol supplementation in healthy adults- a single blind randomized control trial.

BACKGROUND: Vitamin-D (VD) has been shown to be associated various skeletal and non-skeletal benefits. Despite synthesis in the body, 70-80% of population has been found to be VD deficient, due to poor sunlight exposure, increasing environmental pollution, indoor habits etc. Institute of medicine recommended daily allowance (RDA) of 600 IU/day, while Endocrine society recommends a daily intake of 1500-2000 IU/day for age group 19-70 years. In the absence of mandatory food fortification with VD, supplementation is an effective alternate strategy to mitigate the issue of VD deficiency. Optimal supplementation dose for achieving and maintaining sufficient VD levels in Indian adults is still not known. AIM: To evaluate optimal dose of oral cholecalciferol supplementation to achieve and maintain serum hydroxy vitamin D [25(OH)D] sufficiency in Indian adults. METHODOLOGY: In this single center blinded randomized control study, a total of 168 healthy subjects age (18-60 years) were randomized in four groups (A, B, C and D). Subjects were supplemented with 600, 1000, 2000 IU/day and 60,000 IU/month of cholecalciferol to group A, B, C and D in two phases, winter phase and summer phase of three months each with a washout period of three months in between. Serum 25(OH)D, iPTH, calcium, phosphorus, alkaline phosphatase levels and urine calcium/creatinine ratio was assessed at baseline, 12 weeks, 24 weeks and 36 weeks. RESULTS: The mean increase in serum 25(OH)D following supplementation was 21.67±6.54, 32.50±7.33 and 27.72±5.64 ng/ml after three months, 25.96±7.95, 31.52±8.95, 48.05±9.88 and 40.73±12.96 ng/ml after six months of supplementation in group A, B, C and D respectively, with 9.1%, 16.2%, 50% and 39.5% of subjects achieved levels of >30ng/ml after three months and 27.3%, 59.5%, 93.8% and 76.3% after six month of VD supplementation in group A, B, C and D respectively. Supplementation with VD at various doses raised serum 25(OH)D levels in a dose dependent manner, with an average rate constant of 1.79±0.79 ng/ml/100IU/day. Higher BMI and baseline serum 25(OH)D levels negatively associated with gain in serum VD levels. Overall, secondary hyperparathyroidism decreased from 29.3 to 8·6% post-supplementation. No significant difference in urinary Ca/Cr ratio between baseline and post supplementation was noted. CONCLUSION: In accordance with the level of treatment, various oral cholecalciferol regimens improved serum 25(OH)D levels in all the subjects, but the 2000 IU/day achieved the best results while being safe. Daily supplementation with 2000 IU of oral cholecalciferol does meet the RDA requirement of achieving serum 25(OH)D of >30ng/ml in 94% subjects. Whether RDA of 600 IU/day, recommended by IOM is sufficient to combat VD deficiency in our population, is debatable. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.