Hmmm, maybe I will go out and buy me a box of Cheerios!

huh huh huh... she said "oral bioavailability"...

Does that include taking a B12-supplement as an option? (By which I mean, I know some vitamins are just better accessed through food than through supplements, so I'm wondering if the oral bioavailability of B12 is being compared to its availability in other foods only for this study, or also to its o-ba when taken alone or with other supplements.)

Yep. B-12 supplements have extremely poor oral bioavailability.

Which is why, if you are critically low in B-12, you get intramuscular shots of the stuff.

hmmm... interesting. My doc sez I'm anemic, but not low in iron-- that my red blood cells are unusually large, which usually points to a B12 deficiency. I told her "but I take a B12 every day," and she said, well let's be sure to get you back in here to test your B12 levels." so... um, yeah, maybe it would be a good idea for me to prioritize actually doing that.

iiinteresting... thanks!

Yep, you should do that. The side effects of B-12 deficiency are bad.

This is a good summary of B-12 anemia:
http://www.nlm.nih.gov/medlineplus/ency/article/000574.htm

And this is a MUCH longer, but more detailed discussion of B-12 and all the various elements of how your body gets it & uses it and what goes wrong when you don't have enough.
http://ods.od.nih.gov/factsheets/vitaminb12.asp

Doesn't it depend on the cereal?

Sure, some cereals are likely to have more B-12 than others, but I doubt it matters much. Most of them are fortified, even the super sugary ones, with the same plant-based B-12 stuff. Clearly, reading the nutrition information is a better guide than I am, but most of the variation between cereals seems to be in the fiber content and calorie count.