By Dan Baumgardt, University of Bristol

BRISTOL (UK): (Jul 23) The late, great comedian Barry Humphries (of Dame Edna fame) once spoke whimsically about the health benefits of kale. Just one fistful, he joked, contained enough essential vitamins, minerals and trace elements to keep you in a sedentary position in the bathroom for two whole days. Apparently, it wasn’t tasty enough to justify a second helping.

In a world where “superfoods” are relentlessly marketed for their supposed ability to deliver all the nutrients we need, it’s worth asking: which vitamins really are essential? And aside from kale (which I actually rather like), what foods help us meet our daily needs?