Relationship Between Vitamin D Deficiency and Postpartum Depression

Background/Objectives: Postpartum depression (PPD) affects approximately 10–20% of women during and after pregnancy, posing significant risks to maternal health, infant development, and family dynamics. Identifying modifiable risk factors is essential for prevention. Emerging evidence suggests that vitamin D, a neuroactive steroid hormone involved in neurotransmitter synthesis, neuroinflammation regulation, and calcium homeostasis, may play a protective role against mood disorders, including PPD. Methods: The search was conducted through a comprehensive search of the PubMed, Scopus, and Web of Science databases using a combination of Medical Subject Headings (MeSH) and free-text terms including “vitamin D”, “25-hydroxyvitamin D”, “deficiency”, “pregnancy”, “postpartum”, “depression”, “antenatal depression”, “maternal mental health”, and “perinatal mood disorders”. Results: Numerous observational studies and systematic review reports around the world reinforce the potential global relevance of vitamin D insufficiency. This study advances personalized and precision medicine approaches by emphasizing the importance of individualized screening for vitamin D deficiency during pregnancy and postpartum, enabling tailored interventions that could mitigate the risk of postpartum depression. Conclusions: In conclusion, while a definitive causal relationship between vitamin D deficiency and perinatal depression remains unproven, screening for vitamin D levels during pregnancy could serve as a low-risk intervention to support maternal mental health. Future research should focus on well designed, large-scale randomized trials and standardization of diagnostic criteria to clarify vitamin D’s role in preventing perinatal depression. Recognizing vitamin D status as a modifiable biomarker allows for targeted nutritional and pharmacological strategies to optimize maternal mental health.