r[t_] = {3 Sin[t], 4 Cos[t], t};
rderiv[t_] = D[r[t], t];
Manipulate[
 Show[ParametricPlot3D[Evaluate[r[t]], {t, 0, 2 Pi}, AspectRatio -> 1,
    AxesLabel -> {x, y, z}, PlotStyle -> {Green}, 
   PlotRange -> {{-6, 6}, {-6, 6}, {0, 7}}], 
  Graphics3D[{Thick, Red, Arrow[{r[m], r[m] + rderiv[m]}]}]], {m, 0, 2 Pi}]