High blood pressure is the leading risk factor for heart disease and stroke. Approximately 12% of the population have a particular genetic factor (known as the TT genotype) which increases the risk of high blood pressure. Previous studies conducted at this centre have shown that taking the B-vitamin riboflavin, for up to 3 months, decreases blood pressure in adults with the TT genotype. It is currently not known how riboflavin lowers blood pressure in those with the TT genotype but it could be as a result of altering blood levels of nitric oxide. Nitric oxide causes blood vessels to expand, leading to improved blood vessel function, an important predictor of cardiovascular health. However, the effect of riboflavin supplementation on nitric oxide and blood vessel function has not been previously studied. Furthermore, it is unclear whether taking riboflavin over a shorter period of time or at doses higher than 1.6 mg/d can also lower blood pressure and improve blood vessel function in this at risk group. Therefore, the aim of this study is to assess the effects of riboflavin supplementation on blood pressure, biomarkers of nitric oxide bioavailability and blood vessel function. It is hypothesised that riboflavin supplementation will increase nitric oxide bioavailability, leading to reduced blood pressure and improved blood vessel function and, and that a higher riboflavin dose will lead to greater reductions in blood pressure.

Inclusion Criteria:

• Male
• Aged 60 years and below
• Pre-screened for MTHFR 677TT genotype (TTs and CCs individuals only invited)

Exclusion Criteria:

• Consumer of B-vitamin supplements
• Consuming medication that interferes with B-vitamin metabolism

Male only

Company funded work, no plan to share IPD