Low 25-hydroxyvitamin D level is independently associated with non-alcoholic fatty liver disease

Abstract Background and aims We sought to explore associations between serum 25-hydroxyvitamin D [25(OH)D] levels and non-alcoholic fatty liver disease [NAFLD] in an integrated healthcare delivery system in the U.S. Methods and results Six hundred and seven NAFLD cases were randomly matched 1:1 with controls for age, sex, race and season of measurement. Conditional logistic regression was used to evaluate if serum 25(OH)D levels were associated with increased odds of NAFLD (diagnosed by ultrasound) after adjusting for body mass index and history of diabetes, renal, peripheral vascular and liver diseases (model 1) and also for hypertension (model 2). Mean (SD) serum 25(OH)D level was significantly lower in the group with NAFLD as compared with that in the matched control group (75 ± 17 vs. 85 ± 20 nmol/L [30 ± 7 vs. 34 ± 8 ng/mL], P < 0.001). Inadequate 25(OH)D status progressively increased the odds of NAFLD when classified categorically as sufficient (25(OH)D 75 nmol/L [>30 ng/mL], reference group), insufficient (37–75 nmol/L [15–30 ng/mL]; adjusted odds ratio [OR]: 2.40, 95% confidence interval [CI]: 0.90–6.34) or deficient (