LSC Abstract – Effects of vitamin D supplementation on perioperative markers of inflammation in patients at risk of acute respiratory distress syndrome (ARDS)

Vitamin D deficiency is associated with increased risk of ARDS post-oesophagectomy. We recruited patients to a double-blind, randomised controlled trial of high dose Vitamin D supplementation 3-14 days pre-oesophagectomy. 79 patients were randomised to receive placebo or 300,000IU oral Vitamin D liquid 3-14 days prior to oesophagectomy. Blood samples were collected pre-dose, post-dose (pre-op) and post-op and analysed for 25-OH and 1,25-dOH Vitamin D, inflammatory cells and cytokines. Broncho-alveolar lavage fluid was collected at the end of the operation. PICCO biomarkers of alveolar capillary damage (EVLWI and PVPI) were measured pre- and post-op. Vitamin D supplementation was well tolerated and resulted in significant increases in circulating levels (p<0.0001). Post supplementation (pre-op), patients who received the active drug had significantly lower levels of plasma IL6 (p=0.02) and increased numbers of circulating Treg cells (p=0.027). Perioperative changes in extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) were greater in patients who received placebo. There was a significant correlation between preoperative circulating levels of 25-OH Vitamin D and alveolar macrophage efferocytosis (r=0.469, p=0.005). Post-op, circulating levels of s-TNFR-1 (p=0.05) and s-TNFR-2 (p=0.02) were increased in patients who received the active drug. In summary, Vitamin D supplementation is a safe intervention which reduces biomarkers of perioperative inflammation. Pre-operative supplementation should be considered in patients at risk of Vitamin D deficiency.