Vitamin D deficiency is a commonly observed global phenomenon in both the general population as well as hospitalized patients, especially critically ill patients. Many studies have demonstrated an association between vitamin D deficiency and risk of chronic diseases, including cardiovascular disease, diabetes, cancers, autoimmune diseases, and infectious diseases. Vitamin D deficiency is also associated with multiple adverse health outcomes, including increased morbidity and mortality in critically ill patients. The purpose of this review article is to present the current knowledge of clinical outcomes as well as the positive and adverse effects of vitamin D supplements on the relationship between vitamin D status and critical illness. In addition, future strategies for dealing with vitamin D deficiency are suggested.

In terms of nutritional therapy after pancreatectomy, there is no need for routine use of artificial nutrition supplementation except in the case of malnutrition or complications. Postoperative pancreatic fistula (POPF) is one of the most representative complications of pancreatectomy, and adequate nutritional support is important for management of POPF. Oral diet or enteral nutrition (EN) treatment is preferred over parenteral nutrition (PN) since oral diet or EN results in higher POPF closure rates and lower complication rates than EN. Postoperative pancreatitis is usually managed according to the general principle of acute pancreatitis. There is no need to provide specialized nutrition therapy for mild pancreatitis, whereas moderate-to severe pancreatitis should be treated with early specialized nutritional therapy. EN is a more preferred nutritional supplement method over PN due to its lower complication rate, shorter hospital stay, less frequent multi-organ failure, and mortality. Long-term sequelae after POPF or pancreatitis include exocrine or endocrine insufficiency. In the case of exocrine insufficiency, exocrine replacement therapy should be administered. Moreover, endocrine insufficiency, commonly represented by diabetes mellitus (DM), should be managed based on guidelines for type 1 or 2 DM.

Patients with chronic liver disease have a high risk to malnutrition. Proper nutrition should be provided through a proper nutritional assessment. Enteral nutrition is recommended as a nutritional supplement because it maintains the intestinal mucosa, reduces infectious complications, is less costly than parenteral nutrition, and is more physiological to use intestine. The purpose of this review is to define the nutritional deficiencies of patients with liver disease and to show the indications for enteral nutrition and to validate the efficacy of enteral nutrition. According to the various guidelines and researches, enteral nutrition is used as a solution to the nutritional problems caused by patients with liver disease. The optimal enteral formula will be selected on the nutritional problems. It is expected that the enteral nutrition will reduce especially postoperative complications, intraperitoneal complications, pneumonia, and wound infection. The enteral nutrition for patients with chronic liver disease should be actively implemented.