Spend 60-70% of your time cycling (i.e. for every 10 hours training cycle 7 hours run 2 hours and swim 1 hour) This is only a very basic guide line for injury prevention and you will get some cross over in fitness, the better you are on a bike your ironman marathon will be easier to complete.
People with liver disease and high alcohol intake may be at risk for liver toxicity from vitamin A supplementation. Vitamin A toxicity may lead to intrahepatic cholestasis, where bile cannot flow from the liver into the intestines. Vitamin A may cause low blood pressure. Caution is advised in people with low blood pressure or in those taking drugs or herbs and supplements that lower blood pressure.
Fat-soluble vitamins, like vitamins A and D, are generally more toxic because they're stored in your body's tissues. Water-soluble vitamins are not stored in your body, but some of them -- like vitamin C and some B vitamins -- can cause toxicity too.