Exploring the Link Between Vitamin K and Depression: A Systematic Review.

Area of Science:

• Neuroscience
• Nutritional Psychiatry
• Biochemistry

Background:

• Depression is a complex disorder linked to inflammation, oxidative stress, and metabolic dysfunction.
• Vitamin K, traditionally known for coagulation and bone health, is increasingly explored for its neurobiological roles.
• Potential links between vitamin K and mood regulation are emerging.

Purpose of the Study:

• To systematically review the association between vitamin K and depressive symptoms.
• To explore potential mechanisms underlying this association.

Main Methods:

• Systematic literature search across major databases (PubMed, Scopus, etc.) following PRISMA 2020 guidelines.
• Included human and animal studies assessing vitamin K status (dietary intake, serum levels) and depression outcomes.
• Analyzed eleven observational studies, one RCT, and two preclinical studies.

Main Results:

• Most observational studies indicated an inverse relationship between vitamin K levels/intake and depressive symptoms.
• A small RCT showed modest depression score improvement with vitamin K2 supplementation in PCOS women.
• Preclinical studies reported behavioral benefits and reduced oxidative stress with vitamin K2.

Conclusions:

• Preliminary evidence suggests vitamin K may play a role in depression pathways.
• Current evidence is limited by study design (e.g., cross-sectional) and lack of depression-specific models.
• Further research is needed to investigate mechanisms like inflammation reduction, oxidative stress modulation, and vitamin K-dependent protein signaling in depression.