How much iron is in your rations?

If you're like me, you don't really have much of an idea what the hell iron rations look like, much less what they're made of.  As a kid I assumed they were cakes made of compressed Product 19; that assumption hasn't changed much in the intervening years.  [Does Kellogg's still make Product 19?  I don't think I've seen it since the 80s.]

Anyway, my recent foray into Equipment Theory has led me to seek out a clearer image of what sort of food my PCs are noshing on down on the 5th level of Adventure Module FU2 Abyss of Tumescent Malice.  Here are a few options I've discovered:

Dungeon Pucks—Unpalatable crumpets of dwarven manufacture, they are comprised of rendered catoblepas lard and quarry dust; only the truly hungry can bring themselves to eat one of these. It is said that rats turn up their noses at these biscuits and no known mold can find purchase on its dense surface.  Each provides one meal worth of sustenance, though it is a mean existence; after a week of consumption, save vs. Will to Live or sublimate into wraith-form.

Cialembas—Sickly-sweet tortillas made of acorn flour and pixie semen baked in an oven made of sugar cane, they provide lite yet satisfying fare, can be carried in great quantities without impinging on encumbrance, and cause prolonged erections. Extended use may result in cavities and/or spontaneous gender reassignment. Beware: acquisition of these wafers requires interaction with high elves of exceptionally tiresome demeanor.

Uruk-hooch—Foul but invigorating liquor made from goblin adrenal glands and Wild Turkey.  Small doses allow for improved strength and stamina; prolonged use causes psychosis of the liver.  Highly corrosive to metal, must be stored in glass or ceramic containers.  It is rumored to be an antidote to some of the side-effects of Dungeon Pucks and Cialembas.