Comment on "New conditions for a total neutrino conversion in a medium"

We show that the conditions for total neutrino conversion found in [1] are equivalent to the conditions of maximal depth (parametric resonance) and ($\pi/2 + \pi k$) - phase of parametric oscillations. Therefore the effects considered in [1] are a particular case of the parametric resonance in neutrino oscillations. The existence of strong enhancement peaks in transition probability P rather than the condition P=1 is of physical relevance. We comment on possible realizations and implications of the parametric enhancement of neutrino oscillations.