Discussing Vitamin D deficiency recently as a cause of vestibular symptoms, combined with concern about Covid and it being winter in a lot of places made me think of taking Cod Liver Oil.
Apparently brands prepared from wild fish are best.
Here’s a good article on brands available in U.K. (but the discussion is surely relevant wherever you live as issues are the same):
Interesting the link with Covid though. Remember reading about the adverse effect having low Vitamin D was having on Covid patients and somehow got the impression it was Covid specific but now it seems not. Read a paper very recently which long predates Covid and apparently low vitamin D is the strongest indicator that anybody taken into ICU for any condition whatsoever who happens to be Vitamin D deficient has a very much lower survival rate than a person with normal levels.