You should read details section of ViewPoint:

Then you would know to specify ViewPoint -> {0, 0, Infinity}
. You can also play
Manipulate[
ParametricPlot3D[{Sin[t],Cos[t],t},{t,-Pi,Pi},
Axes->False,ViewVertical->{0,1,0},ViewPoint->Dynamic@{0,0,d}],
{d,-10,10}]
