LD50 is usually determined using rodent studies. How much Vitamin D causes an overdose in half of a population of mice?
The dose makes the poison.
And with drug safety, in practice LD50 is less important than how close a therapeutic dose is to a lethal one. If a drug takes 2g/kg to kill you but you need 1g/kg to work, that’s way more dangerous than one that takes .02g/kg to kill you but only needs .0002g/kg to work.
LD50 is usually determined using rodent studies. How much Vitamin D causes an overdose in half of a population of mice?
The dose makes the poison.
And with drug safety, in practice LD50 is less important than how close a therapeutic dose is to a lethal one. If a drug takes 2g/kg to kill you but you need 1g/kg to work, that’s way more dangerous than one that takes .02g/kg to kill you but only needs .0002g/kg to work.