Abstract P2062: Vitamin D Supplementation Improves Vascular Function in Adolescents Suffering from Orthostatic Intolerance

Abstract

Background: In previous work we identified a group of adolescents whose diagnostic workup for chronic unexplained nausea revealed underlying cardiovascular instability manifesting as orthostatic intolerance (OI) and syncope. These patients exhibited impairment in autonomic and vascular function and excessive release of catecholamines upon head up tilt compared to pre tilt. They also had low vitamin D level that correlated with the severity of symptoms on tilt. In this pilot study we hypothesized that vitamin D supplementation to normal levels will improve the vascular function in these participants. Methods: A cohort of ten Adolescents (mean age= 16.3 years) who are vitamin D deficient had a head up tilt at baseline and after two months of vitamin D supplementation (2000-5000 IU daily based on baseline level). Heart rate, blood pressure, cardiac work index, arterial compliance and pulse wave velocity (PWV) were measured in supine position. Results: As shown in the table. Compared to baseline, vitamin D supplementation improved vitamin D level, arterial compliance and reduced cardiac work index under stress challenge and baseline PWV. Conclusions: Vitamin D supplementation for two months restored vitamin D to normal levels and was associated with improvement in the vascular function. These data provides evidence of potential therapeutic benefit of vitamin D supplementation for patients suffering from orthostatic intolerance and syncope who are vitamin D deficient.