Investigating the effect of vitamin D supplementation on improving liver function and its enzymes in people with fatty liver

The liver is a large organ on the right side of the body. The normal weight of an adult liver is about ۱۲۰۰ to ۱۵۰۰ grams. The liver is considered one of the most important organs of the body, detoxification of drugs, disposal of products caused by the destruction and regeneration of red blood cells in the form of bile, storage of sugar as glycogen, and regulation of sugar and fat metabolism are among the most important roles of the liver in the body. Steatosis means accumulation of fat in the cells. When this accumulation occurs in liver cells, it is called liver steatosis or fatty liver. A mild to moderate increase in the liver enzymes AST (aspartate aminotransferase) and ALT (alanine aminotransferase) is one of the common laboratory symptoms in the diagnosis of fatty liver disease. Vitamin D is a molecule with extensive anti-fibrotic, anti-inflammatory, and insulin-sensitizing properties, which have been proven also in hepatic cells and is involved in immune-metabolic pathways within the gut–adipose tissue–liver axis. Vitamin D plays a key role in bone metabolism and muscle function. This vitamin facilitates the absorption of calcium and phosphorus from the intestine and inhibits the release of parathormone hormone. According to research, vitamin D supplementation has a significant effect on the lipid indices of liver enzymes. Epidemiological data support a relationship hypovitaminosis D and the presence of NAFLD and steatohepatitis (NASH); however, results from vitamin D supplementation trials on liver outcomes are controversial.The purpose of this article is to review the latest evidence regarding the effectiveness of vitamin D supplements on liver outcomes in people with MAFLD.