# Vitamin D3 as an immunomodulatory agent: molecular mechanisms, clinical translation, and precision therapeutic strategies

## TL;DR

Vitamin D3 helps regulate the immune system and reduce inflammation, with new delivery methods and precision medicine improving its effectiveness for various diseases.

## Contribution

The paper introduces precision medicine strategies and advanced delivery systems to enhance Vitamin D3's clinical efficacy.

## Key findings

- Vitamin D3 modulates immune responses by inhibiting pro-inflammatory pathways like NF-κB and NLRP3.
- New delivery systems such as nanoemulsions and liposomes improve Vitamin D3 bioavailability and stability.
- Clinical applications show promise in treating diseases like psoriasis, SLE, and IBD with tailored Vitamin D3 therapies.

## Abstract

Vitamin D3 (VitD3) deficiency affects over one billion individuals globally, representing a critical modifiable risk factor for immune-mediated diseases. Beyond its classical role in calcium metabolism, Vitamin D3 orchestrates immune homeostasis through vitamin D receptor (VDR) signaling, exerting profound regulatory effects on both innate and adaptive immunity. Mechanistically, Vitamin D3 maintains the balance between antimicrobial defense and inflammatory suppression by inhibiting key pro-inflammatory pathways including nuclear factor κB (NF-κB) and the NOD-like receptor protein 3 (NLRP3) inflammasome, while activating the Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2)-mediated antioxidant defense system. However, the immunomodulatory effects of Vitamin D3 exhibit significant inter-individual variability, with clinical efficacy highly dependent on patient-specific factors including serum 25-hydroxyvitamin D [25(OH)D, calcifediol] levels and VDR gene polymorphisms, driving a paradigm shift from empirical supplementation toward biomarker-guided precision medicine. Novel delivery systems—nanoemulsions, twin-screw extrusion technology, and liposomes—effectively overcome bioavailability and stability limitations of traditional preparations. This review systematically examines the immunomodulatory mechanisms of Vitamin D3, evaluates clinical translation evidence in psoriasis, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type 1 diabetes mellitus (T1DM), inflammatory bowel disease (IBD), and discusses precision medicine strategies and therapeutic potential.

Infographic illustrating the roles and mechanisms of Vitamin D3 in immune regulation and anti-inflammation. Top left shows Vitamin D3 enhancing defense and regulating inflammation through various immune cells. Top right highlights molecular mechanisms including NF-κB, NLRP3, and Nrf2 pathways. Bottom left displays clinical applications for diseases like psoriasis, SLE, RA, T1DM, and IBD. Bottom right presents advanced delivery systems, such as nanoemulsions, extrusion techniques, and nasal administration, emphasizing improved stability and bioavailability. Central circle denotes themes: immunoregulation, anti-inflammation, clinical trial, and delivery system.