Portioned out mince containing vitamin (6)
I believe the answer is:
shared
'portioned out' is the definition.
('share' can be a synonym of 'portion out')
'mince containing vitamin' is the wordplay.
I cannot really understand how this works, but
'vitamin' could be 'e' (E is an example) and 'e' is found in the answer.
The remaining letters 'shard' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for shared that I've seen before include "Participated in" , "Possessed in common" , "Apportioned" , "Used by more than one" , "Communal" .)