I read a study a while ago, the study found common vitamin deficiency in depressed humans.
I researched more about it and looks like some of the deficiency in the vitamins in the study are correlated with higher IL-17 levels.
Carnitine: Seems to have some effect in decreasing IL-17?
Vitamin D: Highly impacts IL-17 (https://pmc.ncbi.nlm.nih.gov/articles/PMC4609465/)
COQ10: Decreased plasma levels of IL-17 (https://www.clinicalnutritionespen.com/article/S2405-4577(22...)
Folic Acid: Reduces IL-17 (https://pmc.ncbi.nlm.nih.gov/articles/PMC8839991/)
Lutein: I didn't find any study that seems to study the effect on IL-17
Citrulline: No relevant studies
This is the study I'm referring to: https://www.nature.com/articles/s41398-023-02696-9
I think we're getting closer to find some blood level correlations, so we can fix them!
I can say for a fact when I take CoQ10, I feel my energy levels going up so it really has some effect.