Vitamin D vs Probiotics

for mood

Stronger evidence: tie

Stronger effect: tie

Safety: Vitamin D carries a minor interaction; Probiotics has none recorded.

For mood, the two are evidence-matched; the difference is in effect and safety.

Vitamin D

grade C low certainty

small mood benefit, mostly in people who are deficient

Probiotics

grade C low certainty

small effects on mood/anxiety in some "psychobiotic" trials; strain-specific, heterogeneous

strain-dependent, adults
sources: PMID:00000005 · PMID:42221774