Well each person weighs a different kg. So that is a impossible statement since the Mg amount will not adjust to the kg the persons weights. In tap water.
also the mg/kg statement is also utterly FALSE....
Say if a person is 50kg and the mg is 525. The dose of the lithium would be adjusted for that person that weights. 50kg or 110 lbs. Comes to be that person can take up to 26,250 mg according to the quoted statement.....that person will not Overdose??
I am not sure where you got your info from, but 26,250 mg is an extremely toxic dose of lithium.
I am not sure but do you realize you only prove my point? You'd need about 200 of lithium pills to got a lethal dose? It's not toxic when you drink lithium from water in trace amounts.
Safety (MSDS) data for lithium carbonate
Lithium Toxicity data
(The meaning of any abbreviations which appear in this section is given here.)
ORL-RAT LD50 525 mg kg
IPR-RAT LD50 156 mg kg
SCU-RAT LD50 434 mg kg
IVN-RAT LD50 241 mg kg
Hardly toxic compared to selenium (absolutely required for health):
SELENIUM
A dose of selenium as small as 5 mg per day can be lethal for many humans.
Periodic Table of Elements: Selenium - Se (EnvironmentalChemistry.com)
Selenium is found in water as well.
Copper is essential but has even worse LD50 - just 3.5mg/kg.
Point here is that it's the dose that counts. All substances are poisons if they reach beyond the point where your body cannot metabolize.