>But i am wondering if  " deficiencies" are not more representing a
>difficulty in the regulating system of nutrients levels.than a truely
>deficient intake. ( and especially if deficiencies are measured in the
>blood).

Yes, for instance people with Down Syndrome have very low serum levels of
calcium and with that information only you would want to supplement, but the
fact is they have soft tissue calcification (including teeth- they hardly
ever get cavities). In other words the calcium gets into the cells and has a
hard time getting back out. It's something to think about.
Paula