  The Sun provides an excellent target for studying spin-dependent dark
matter-proton scattering due to its high matter density and abundant hydrogen
content. Dark matter particles from the Galactic halo can elastically interact
with Solar nuclei, resulting in their capture and thermalization in the Sun.
The captured dark matter can annihilate into Standard Model particles including
an observable flux of neutrinos. We present the results of a search for
low-energy ($<$ 500 GeV) neutrinos correlated with the direction of the Sun
using 7 years of IceCube data. This work utilizes, for the first time, new
optimized cuts to extend IceCube's sensitivity to dark matter mass down to 5
GeV. We find no significant detection of neutrinos from the Sun. Our
observations exclude capture by spin-dependent dark matter-proton scattering
with cross-section down to a few times $10^{-41}$ cm$^2$, assuming there is
equilibrium with annihilation into neutrinos/anti-neutrinos for dark matter
masses between 5 GeV and 100 GeV. These are the strongest constraints at GeV
energies for dark matter annihilation directly to neutrinos.
