Although research on collagen is relatively new, the skin-supporting evidence so far is promising—especially with high-quality supplements containing multiple types of collagen and pro-collagen.

Krill oil is rich in astaxanthin, choline, EPA, and DHA and improves dopamine-dependent behavior and cognition in roundworms and protects dopaminergic neurons from age-related degeneration.

Vitamin C may be able to shorten the length of cold symptoms and possibly prevent infections in higher-risk populations—vitamin C supplements tend to be poorly absorbed, especially in higher doses. 

Higher levels of the omega-3 eicosapentaenoic acid (EPA) improved levels of abstract reasoning in middle-aged adults, suggesting the omega-3’s support cognitive health.