No, in my opinion vitamin A supplements are not safe. And again no, in my opinion whole food plant-based vegans do not need vitamin A supplements. This is a rare example of a straightforward answer to a nutritional question :-)
Vitamin A (retinol and other retinoids) is a fat soluble vitamin and can accumulate in the body, particularly in the liver, and can reach toxic levels if obtained from a supplement or if too much preformed vitamin A is obtained from animal sources such as liver and cod liver oil for example. Curiously, the most toxic concentrated source of preformed vitamin A is polar bear liver! :-) Read more . . .