but, wait.

if you go back with the pasta, what i typed was:

pasta - 188*.55 = 103.4 (c)

i must have misread the data as 188 mg/100g, in which case 55% of that is 103.4.

but, the data is 188 μg/g which is 188 μg/g*(1 mg/1000 μg) = .188 mg/g = 18.8 mg/100g.

then, 18.8*.55 = 10.34.

but, the usda source (see previous posts) has the data for spaghetti, dry, enriched listed at 140 mg/100g, and then 140*.55 = 77 mg is the correct calculation, and actually enough to not require a supplemental source.

so, what is the right answer? that's a big spread.

i dunno.

i'll think this through soon.