Ironman triathletes must complete the bicycle course at the World Championships in 10 hours, 30 minutes. The top women, however, will finish the bike race in about half that time. As with the swimming cutoff, failure to achieve the bicycle cutoff time eliminates the triathlete from the event.
In the past, the requirements for vitamin K only considered its classical function in coagulation; an RDA was given for vitamin K in the United States (54, 58) and a safe and adequate intake level was given in the United Kingdom (65).
Warfarin and related 4-hydroxycoumarin-containing molecules decrease blood coagulation by inhibiting vitamin K epoxide reductase, an enzyme that recycles oxidized vitamin K 1 to its reduced form after it has participated in the carboxylation of several blood coagulation proteins, mainly prothrombin and factor VII.