Effect of 1,25-dihydroxy vitamin D3 on inflammation, antimicrobial peptide, and D-dimer levels in Escherichia coli-induced sepsis in neonatal calves

This study evaluated the immunomodulatory, antimicrobial, and anticoagulant effects of 1.25-dihydroxy vitamin D3 in neonatal calves with Escherichia coli-induced sepsis. Thirty neonatal Simmental calves were assigned to three groups: Control (n = 10), Medical Treatment (MT; n = 10), and Medical Treatment plus vitamin D₃ (MT + D₃; n = 10). The MT group received standard sepsis therapy, while the MT + D₃ group was additionally administered 20,000 IU/kg intramuscular vitamin D₃. Blood samples were collected on days 0, 1, 3, and 5 to analyze inflammatory cytokines (NF-κB, TNF-α, IL-1β, IL-10), cathelicidin, D-dimer, iron levels, and hematological parameters. Biochemical indicators including liver, kidney, and heart function, as well as calcium and vitamin D₃ levels, were assessed on days 0 and 5. The MT + D₃ group showed significant clinical and laboratory improvements compared to the MT group. Notably, SpO₂ levels increased, and metabolic acidosis resolved earlier. Hematological findings indicated reduced sepsis-associated anemia, with better preservation of RBC, HGB, and HCT levels. Inflammatory cytokines (NF-κB, TNF-α, IL-1β) significantly decreased, and IL-10 levels were more effectively regulated. Lower D-dimer levels indicated improved coagulation balance. Although cathelicidin levels initially increased, their subsequent decline by day 5 suggested controlled innate immune activation. In conclusion, vitamin D₃ supplementation in combination with standard treatment effectively reduced systemic inflammation, supported innate immunity, and improved coagulation in neonatal calves with sepsis. These results suggest that vitamin D₃ may serve as a beneficial adjunct therapy in bovine neonatal sepsis. Further research is needed to determine optimal dosing strategies and long-term clinical benefits.