Abstract P125: The Effects Of Vitamin D Supplementation On Orthostatic Hypotension: Results From STURDY

Abstract

Background: In some trials, vitamin D supplementation is associated with a lower risk of falls. Observational evidence has implicated orthostatic hypotension (OH) as a potential mechanism for this association. Objective: To determine if higher doses of vitamin D supplementation reduce the risk of OH. Methods: The Study to Understand Fall Reduction and Vitamin D in You (STURDY) was a double-blind, randomized, response-adaptive trial that tested the effects of 4 doses of vitamin D3 (200, 1000, 2000, and 4000 IU/day) on fall risk in adults age 70 years and older with low serum vitamin D levels (10-29 ng/ml). OH was determined at baseline, 3, 12, and 24 months by taking the difference between seated and standing blood pressure. OH was defined as a drop in systolic or diastolic blood pressure of at least 20 or 10 mmHg, respectively, after 1 minute of standing. Participants were also asked about symptoms related to OH during the OH assessment and in the past month. Odds ratios were determined using generalized estimating equations to account for repeat measurements. Results: Among 387 participants with 924 OH assessments, mean age was 77 ± 5 years, 42% were women, and 17% black. Mean baseline systolic/diastolic blood pressure was 129 ± 19/67 ± 11 mm Hg; 2.3% had OH. Compared to 200 IU/day, 1000, 2000, and 4000 IU/day did not lower risk of OH during the trial ( Table ). Furthermore, vitamin D dose was not associated with orthostatic symptoms as participants stood up or after standing. In a subset with more detailed symptom assessments, there was no association between vitamin D dose and orthostatic symptoms or functional limitations in the preceding 30 days. Conclusions: Daily, higher dose vitamin D supplementation was not associated with OH or its symptoms. These findings do not support vitamin D as an intervention to prevent OH.