Sickened by sodium, used tea as an alternative (9)
I believe the answer is:
nauseated
'sickened' is the definition.
('nauseate' can be a synonym of 'sicken')
'sodium used tea as an alternative' is the wordplay.
I cannot really understand how this works, but
'sodium' could be 'na' (Na is the chemical symbol for sodium) and 'na' is located in the answer.
an anagram of 'tea' is 'eat' which is present in the answer.
The remaining letters 'used' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'by' is the link.
Can you help me to learn more?
(Other definitions for nauseated that I've seen before include "Revolted" , "Sickened" , "Disgusted" .)