It's an acquired taste, sort of like Guinness Stout. It's a gooey, salty, beef-flavoured yeast extract that Brits like slathered on a piece of toast. It's Marmite, popularly known in some corners as the "Black Bomb."
Apparently Marmite, loved by some throughout the Commonwealth, is under attack by the Canadian Food Inspection Agency, the same outfit that lets packing plants inspect their own meat products (we know how well that has worked, prime minister Listeria). The Canuckleheads don't want Marmite coming in because it's enriched with vitamins and minerals.
Really, and that's going to take somebody by surprise? It's right there on the label, "contains B vitamins."
So it looks like, if you're into the Black Bomb and you're running low, you might want to stock up while it's still on the grocery store shelves.