  We consider the influence of topological phases, or their vicinity, on the
spin density and spin polarization through a chiral chain. We show the
quantization of the Berry phase in a one-dimensional polarization helix
structure, under the presence of an external magnetic field, and show its
influence on the spin density. The polar angle of the momentum space spin
density becomes quantized in the regime that the Berry phase is quantized, as a
result of the combined effect of the induced spin-orbit coupling and the
external transverse magnetic field, while the edge states do not show the polar
angle quantization, in contrast with the bulk states. Under appropriate
conditions, the model can be generalized to have similarities with a chain with
nonhomogeneous Rashba spin- orbit couplings, with zero- or low-energy edge
states. Due to the breaking of time-reversal symmetry, we recover the effect of
chiral-induced spin polarization and spin transport across the chiral chain,
when coupling to external leads. Some consequences of the quantized spin
polarization and low-energy states on the spin transport are discussed.
