(R)-mevaldate + NADH + H(+) => (R)-mevalonate + NAD(+)
(r)-mevaldate + nadh + h(+) => (r)-mevalonate + nad(+)
(R)-mevaldate + NADH + H(+) => (R)-mevalonate + NAD(+)
(r)-mevaldate + nadh + h(+) => (r)-mevalonate + nad(+)