Nutter in trouble providing a source of nourishment (8)
I believe the answer is:
nutrient
'a source of nourishment' is the definition.
(I've seen this before)
'nutter in trouble' is the wordplay.
'trouble' indicates an anagram.
'nutter'+'in'='nutterin'
'nutterin' with letters rearranged gives 'NUTRIENT'.
'providing' is the link.
(Other definitions for nutrient that I've seen before include "provider of sustenance?" , "Good food" , "Substance that nourishes" , "vitamin maybe" , "Substance essential for growth" .)