  The triviality of the scalar sector of the standard one-doublet Higgs model
implies that this model is only an effective low-energy theory valid below some
cut-off scale Lambda. We show that the experimental constraint on the amount of
custodial symmetry violation implies that the scale Lambda must be greater than
of order 7.5 TeV. The underlying high-energy theory must also include flavor
dynamics at a scale of order Lambda or greater in order to give rise to the
different Yukawa couplings of the Higgs to ordinary fermions. This flavor
dynamics will generically produce flavor-changing neutral currents. We show
that the experimental constraints on the neutral D-meson mass difference imply
that Lambda must be greater than of order 21 TeV. For theories defined about
the infrared-stable Gaussian fixed-point, we estimate that this lower bound on
Lambda yields an upper bound of approximately 460 GeV on the Higgs boson's
mass, independent of the regulator chosen to define the theory. We also show
that some regulator schemes, such as higher-derivative regulators, used to
define the theory about a different fixed-point are particularly dangerous
because an infinite number of custodial-isospin-violating operators become
relevant.
