ALB and Sepsis: Aside from advanced age15, male gender16, sepsis or septic shock18, vascular disease27, and factors which leads to wasting of vitamin C by the kidneys24, our study also identified two novel important predictors of hypovitaminosis C, i.e. abdominal sepsis and serum albumin, using variable importance analysis based on SHAP value (the change in the prediction when the feature is added compared with the baseline for a given prediction37).