Mary, actually it doesn't take too massive amounts.  I have a mom in my
practice who feeds the baby carrots (1 jar) daily because baby "likes
them".  She is usually fairly yellowish with white scelera.  As you say
that is a good clue.  Also some ethnis groups have a yellowish, sallow cast
to their skins.  My mom is very sallow and if she is also pale (like now
because of shingles and pain) she looks jaundiced.  Sincerely, Pat in SNJ