Design: Phase IIa, parallel, double-blind, randomised controlled, single centre clinical trial of 12 month follow-up duration. Population: Older adults (≥65 years of age) with an objective diagnosis of symptomatic orthostatic hypotension Intervention: The intervention will be 5g/day of salt supplementation in the form of encapsulated sodium chloride. Outcome measures: Primary outcome (Feasibility) recruitment and retention rates, adherence with intervention and study protocol, completeness of follow-up. Secondary Outcome (Efficacy): i) clinical: change in Orthostatic Hypotension Questionnaire score, modification/addition of OH pharmacotherapy, and falls events, ii) physiological measures of orthostasis: change in difference between supine and nadir systolic BP, standing BP at 1 minute, 24 hour mean BP measured by 24 hour ambulatory BP monitor, iii) cardiovascular biomarkers. Clinical Importance: A recommendation for long-term increases in salt intake may have adverse cardiovascular consequences, which necessitates the identification of the optimal range of salt intake associated with greatest reduction in falls risk and lowest cardiovascular risk. Our study will provide preliminary evidence of treatment effect and assess feasibility, to inform a definitive trial.