Vitamin D supplementation in subjects with hypovitaminosis D: a randomized double-blind, placebo-controlled trial

Abstract

Introduction: Despite having abundant sunshine all year long, hypovitaminosis D in Indonesia is still surprisingly prevalent. However, hypovitaminosis D in Indonesia has still been severely underdiagnosed and there were even fewer studies on its treatment. Thus, we aim to assess the effectiveness of daily vitamin D supplementation for subjects with hypovitaminosis D.Method: A randomized double-blind, placebo-controlled trial conducted was conducted with a total of 76 healthy, non-obese, working-age participants with hypovitaminosis D. The intervention was daily 1,000 IU of vitamin D3 supplementation for 12 weeks, while the placebo group received a placebo pill. The serum 25(OH)D level was measured pre-intervention, after 4 weeks, and after 12 weeks of intervention. The data were analyzed using an unpaired t-test in SPSS version 24.0. Out of the 81 participants, a total of 76 participants (93.8%) have hypovitaminosis D.Result: The serum 25(OH)D level in the treatment group was significantly higher than in the placebo group after 12 weeks of supplementation. The delta of serum 25(OH)D level after 12 weeks of supplementation was also significantly higher in the treatment group. Furthermore, the serum 25(OH)D level in the placebo group was found to be significantly reduced at the 12th week compared to the baseline. Participants who received daily supplementation of 1000 IU vitamin D3 for 12 consecutive weeks have significantly higher serum 25(OH)D levels than the participants in the placebo group. Same result was also observed when the changes of serum 25(OH)D after 12 weeks were analyzed.Conclusion: Hypovitaminosis D was surprisingly very prevalent among the working-age group in Indonesia. Participants who received daily supplementation of 1000 IU vitamin D3 for 12 consecutive weeks have significantly higher serum 25(OH)D levels than the participants in the placebo group.