The Impact of Vitamin D in Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study in Patients with Morbid Obesity

Abstract

Purpose We aimed to evaluate the association between vitamin D status and hepatic function parameters and scores: Fatty Liver Index (FLI, predictor of hepatic steatosis) and BARD (BMI, AST/ALT ratio and DM, predictor of hepatic fibrosis) in patients with morbid obesity. Patients and Methods Cross-sectional study including patients with morbid obesity followed in our centre between January 2010 and July 2018. Patients with missing vitamin D levels or hepatic profile parameters were excluded. We divided the population according to two cut-offs of vitamin D levels (12ng/mL and 20ng/mL). Results The included population (n=1124) had an average age of 43.3±10.7 years and 84.3% were female. Seventy-point eight percent of the population had vitamin D levels lower than 20ng/mL and 34.8% lower than 12ng/dL. Patients with lower vitamin D levels (<12ng/mL) had higher BMI, hip and waist circumferences and higher prevalence of hypertension. Higher FLI scores [OR= 0.77 (0.07), p<0.01] and ALP levels [β= −0.03 (−0.06, −0.01), p<0.01] associated to lower vitamin D levels. Conclusion Vitamin D deficiency is associated with a higher risk of hepatic steatosis in individuals with morbid obesity. Correction of vitamin D deficiency may have a beneficial role in the management of NAFLD in patients with morbid obesity.

The Role of Vitamins in Non-Alcoholic Fatty Liver Disease: A Systematic Review

“…Vitamin D insufficiency has been associated with biopsy-proven NAFLD [ 5 ] and liver fibrosis [ 27 ]. One study done in morbidly obese patients showed that Vitamin D deficiency is associated with a higher risk of steatosis represented by Fatty Liver Index (FLI) score [ 7 ]. Low levels of Vitamin D activate Toll-like receptors, leading to severe liver inflammation and oxidative stress.…”

“…[ 9 , 18 ]. In chronic hepatic diseases like NAFLD, Vitamin D receptor (VDR) expression is inversely associated with the severity of lobular inflammatory damage [ 2 , 7 , 28 ].…”

“…In addition, Vitamin D favors glucose uptake in the muscle by intensifying the intracellular expression of the insulin receptor substrate (IRS)-1 and enhancing the insulin-dependent glucose transporter 4 (GLUT-4) on fat tissues [ 11 ]. Moreover, besides favoring insulin release from the pancreas, Vitamin D also induces adiponectin release from fat tissue [ 7 ]. In a study involving human patients, serum 25-hydroxyvitamin D concentration correlated with low leptin and high adiponectin levels, irrespective of BMI [ 2 ].…”

“…NAFLD is characterized by increased lipid deposition within the hepatocytes in individuals without a history of excessive alcohol intake, that is <30 g/day for men and <20 g/day for women, after excluding other causes of chronic liver diseases [ 2 ]. NAFLD manifests as a wide range of hepatic damage with varying severity ranging from simple steatosis to a more severe Non-Alcoholic Steatohepatitis (NASH), with or without fibrosis, cirrhosis, and potentially hepatocellular carcinoma [ 7 ]. Although ultrasound can usually diagnose NAFLD, it is only sensitive once the level of fat deposition exceeds 33% [ 2 ].…”

The Emerging Role of Nanomedicine in the Management of Nonalcoholic Fatty Liver Disease: A State-of-the-Art Review

“…Vitamin D is a fat-soluble vitamin that has a wide range of functions in the body. Many studies have shown the beneficial roles of vitamin D supplements in managing NAFLD [26][27][28][29]. However, the role of vitamin D supplementation in NAFLD is still controversial [16][17][18][19][20][21].…”