Effect of 1,25-dihydroxy vitamin Don 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 D(MT + D; n = 10). The MT group received standard sepsis therapy, while the MT + Dgroup was additionally administered 20,000 IU/kg intramuscular vitamin D. 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 Dlevels, were assessed on days 0 and 5. The MT + Dgroup 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 Dsupplementation 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 Dmay serve as a beneficial adjunct therapy in bovine neonatal sepsis. Further research is needed to determine optimal dosing strategies and long-term clinical benefits.