Lay summary
Gout occurs when blood urate increases and uric acid crystals deposit in joints. Repeated gouty attacks lead to joint damage and disability. Prevention of gout requires sustained blood urate <0.36mmol/L. Allopurinol, which inhibits the production of urate, is the most commonly used medication. In some patients the dose is limited by side effects or renal impairment. Recent evidence suggests that supplemental vitamin C will reduce blood urate levels in healthy controls. We aim to determine whether it is feasible to use supplemental vitamin C in the management of gout. We propose to randomise patients to standard treatment with allopurinol or supplemental vitamin C 500mg daily. Outcomes will include the magnitude and timing of reduction in serum urate concentration and patient acceptability which are required to determine final study design. Treatment options for patients poorly tolerant of allopurinol are limited and addition of a therapeutic alternative will provide significant benefit to patients.