You don't understand. I quoted YOUR STUDY to get the levels they determined were good... 70 nmol/l. I then used the 70 nmol/l as the target as used in the other study which said how much you need to take each day to get to the healthy levels YOUR article said. 70 nmol/l. It turns out that is over 8895 IU which only gets you to 50 nmols/l. So you must take more than 10 x the USRDA amounts (600IU a day) to get to the levels YOUR article says are the healthy ones. If you DON'T you have 2.5 x the chance of a heart attack according to YOUR article. So must take over ten times the US recommended daily allowance to avoid 2 and a half times the risk of dying from a heart attack.