They are descended from ancestors who lived in burrows and had
crepuscular activity, ie dawn and dusk, plus they ate a lot of animals
and a lot of livers which are very rich in vitamin A. As a result they
get health problems from too much vitamin D but need more Vitamin A
than people do. We are descended from diurnal ancestors who got most of
their calories from plant sources. Humans are the opposite of ferrets
in relation to A and D so it is absolutely essential that people NEVER
assume that they can postulate toxicity levels or need levels of these
two nutrients from humans to ferrets.

[Posted in FML 7105]