Depression affects over 20 million people globally, causing disability and socioeconomic
burdens. First-line treatments fail in 30-50% of patients. Novel approaches
targeting neuroinflammation and synaptic deficits are needed. Physical activity and
vitamin D3 show promise for treatment-resistant depression. Evaluate effectiveness
of vitamin D3 & mechanisms, and combined physical activity & vitamin D3
supplementation on depression symptom management. Conducted structured
systematic PubMed/Google Scholar search (from 2015) for RCT, full research
observational studies, and meta-analyses, with keywords (depression, physical
activity, vitamin D3, neuroinflammation, combined-interventions and mental
health). Included English peer-reviewed human studies. Physical training reduced
symptoms by 20-30%. This has been accounted for through upregulation of BDNF,
normalization of HPA, and reduced inflammation. Vitamin D3 supplementation
(≥2800 IU/day) in vitamin D deficient groups (<50 nmol/L) was associated with an
improvement in mood. This has been accounted for through enhanced production
of serotonin and suppressed neuroinflammation. Combined interventions had
greater symptom reduction then the monotherapy's, such as physical activity and
Vitamin D3, from combinations in treatment-resistant cases. Combined physical
activity and Vitamin D3 may provide an optimal combined treatment strategy for
depression. Treatment must be personalized depending upon deficiency, status and
severity. Research moving forward must focus on research of large-scale
randomized controlled trials (RCTs) to provide solid evidence, followed by public
health integrated interventions to transmit and work with knowledge findings on
the implementation of findings.
Keywords: Depression, Physical activity, Vitamin D3, Neuroinflammation,
Combined interventions, Mental health
