Woman takes it to be very important (5)
I believe the answer is:
vital
'be very important' is the definition.
(I've seen this in another clue)
'woman takes it' is the wordplay.
'woman' becomes 'val' (val is a name for a woman).
'takes' means one lot of letters goes inside another.
'val' enclosing 'it' is 'VITAL'.
'to' is the link.
(Other definitions for vital that I've seen before include "Energetic - displaying life" , "Essential to life, indispensable" , "Crucial" , "alive" , "Of key importance" .)