The Association between Vitamin D Insufficiency and Nonalcoholic Fatty Liver Disease: A Population-Based Study

Abstract

Previous studies have shown inconsistent results regarding the association between vitamin D insufficiency and nonalcoholic fatty liver disease (NAFLD). We attempted to demonstrate this relationship using population-based data. Vitamin D insufficiency was defined as a 25(OH)D level ≤20 ng/mL. Hepatic steatosis index was calculated to define NAFLD. Significant fibrosis was assessed using Body mass index, AST/ALT Ratio, Diabetes (BARD) score. Logistic regression analyses were performed to determine the relationship between vitamin D insufficiency and NAFLD. Among 1812 participants, 409 (22.6%) had NAFLD. Patients with nonalcoholic fatty liver disease were more likely to be male (56.7%), had higher body mass index (28.1 kg/m2), and had more metabolic syndrome (57.2%). The proportion of vitamin D insufficiency did not differ between NAFLD and non-NAFLD (77.5% vs. 77.4%). Logistic regression analyses showed that BMI, diabetes, and triglyceride level were significantly associated with NAFLD, whereas vitamin D insufficiency was not related. Subgroup analyses involving non-obese participants, male participants, and participants without metabolic syndrome showed similar results. The BARD score and the proportion of significant fibrosis by BARD score did not differ according to vitamin D status. Vitamin D insufficiency was not associated with the presence of NAFLD as assessed by validated noninvasive prediction models.

Vitamin D Levels in Egyptian Patients With Non-Alcoholic Fatty Liver Disease

“…However, our results are in contrary with Li et al [24] 2013, who found no significant differences between patients with NAFLD and those without NAFLD in serum vitamin D levels. Also, Patel et al [25] 2016, Ha et al [26] 2017, De Paula et al [27] 2017 and Park et al [28] 2017 found no association between vitamin D levels and NAFLD (Table 7 summarizes these studies).…”

Inverse Association Between Serum 25-Hydroxyvitamin D and Nonalcoholic Fatty Liver Disease

“…38 However, a Korean case-control study found that S-25(OH)D levels did not differ significantly between the 409 NAFLD cases and 803 controls without NAFLD. 10 In a MR study including 4614 NAFLD cases and 4568 controls of East Asian descent, genetically predicted S-25(OH)D levels were not associated with NAFLD risk. 16 In contrast, our study based on 3 populations of European descent found a consistent inverse association of genetically predicted S-25(OH)D levels with NAFLD risk.…”

“…5 Furthermore, an inverse association between serum 25-hydroxyvitamin D [S-25(OH)D], a clinical marker of vitamin D status, and NAFLD has been observed in several cross-sectional and case-control studies, [6][7][8][9] although not all. 10 A therapeutic effect of vitamin D treatment, such as attenuating hepatic inflammation and improving liver function, were observed in some [11][12][13] but not all 14 clinical trials. These inconsistent findings and possible effects of reverse causality and residual confounding on the associations in the observational studies hinder the causal inference in the association between vitamin D and NAFLD.…”

Beneficial Effect of Vitamin D on Non-Alcoholic Fatty Liver Disease (NAFLD) Progression in the Zebrafish Model

“…NAFLD and low VitD levels are often detected together; hence, VitD deficiency is thought to be involved in the complex pathogenesis of NAFLD [ 59 ]. Although there are indications in the literature that low levels of VitD in NAFLD patients might not be the cause of the disease and cannot predict its severity [ 18 , 19 , 21 , 23 , 24 ], we were nonetheless interested in exploring the option of supplementation with high levels of VitD. We hypothesized that since relatively low levels of VitD supplementation were not enough for these patients, the dose of VitD supplementation should be higher.…”

“…Nevertheless, there is some controversy in the literature. Some studies have found no correlation between VitD and NAFLD, and the levels of VitD could neither determine nor predict the severity of the diseases [ 18 , 19 , 20 , 21 , 22 , 23 ]. Moreover, it was demonstrated that there is no causal association between vitamin D and NAFLD using a bi-directional Mendelian randomization approach in a Chinese population [ 23 , 24 ].…”