Metabolic syndrome (MetS) is an increasingly prevalent condition that comprises a group of risk factors, including abdominal obesity, insulin resistance (pre-diabetes), hypertension and hyperlipidemia, which together significantly increase the risk of type-2 diabetes and cardiovascular disease (CVD). Chronic low-grade inflammation contributes to the insulin resistance and vascular dysfunction observed in MetS. Targeting these inflammatory pathways in MetS may help attenuate progression to the more severe cardiometabolic diseases. Vitamin C is a potent antioxidant with anti-inflammatory properties and is depleted in people with MetS. Therefore, we plan to carry out a study to assess the feasibility of a randomised controlled trial comprising vitamin C supplementation of people with MetS to determine effects on inflammation and other objective and subjective health measures. A diagnosis of MetS provides a window of opportunity to work with those diagnosed to make healthful lifestyle changes to potentially slow or even reverse progression to diabetes and/or CVD.