Women who might become pregnant should be especially cautious with vitamin A supplements or avoid them entirely .

Healthy adults may store vitamin A in their liver for a year or longer, Mulvihill adds. ... Vitamin A supplement dosage. The appropriate dosage for vitamin A supplements varies by person.

Dear M.E.B.: I think many media sources avoid the complexity of the issue. The preferred unit to describe doses of vitamin A are now micrograms RAE, or “retinol activity units.” Different vitamin A ...

If I am taking vitamin A, what is a reasonable dose? I have seen reports taking too much can cause liver damage, but nobody says how much is a problem. — M.E.B.