title: Vitamin D deficiency in non-alcoholic fatty liver disease: The chicken or the egg?
abstract: Serum vitamin D concentration is reduced in patients with non-alcoholic fatty liver disease (NAFLD). Although the mechanism of vitamin D deficiency in liver disease is not fully understood, a few reports have suggested the beneficial effects of vitamin D supplements. The present study investigated changes in serum 25-hydroxy vitamin D level and clinical parameters after total calorie restriction with vitamin D intake reduction in NAFLD patients.
  
  
  
  Newly diagnosed NAFLD patients with elevated aminotransferase levels were chosen for a calorie restriction and weight-reduction program. A total of 82 patients received nutritional education from nutritionists every 2 weeks for 2 months. Serum 25-hydroxy vitamin D level, amount of vitamin D intake, and physical activity were thoroughly investigated.
  
  
  
  The mean serum 25-hydroxy vitamin D concentration was 13.0 ng/ml. Twenty-nine patients (35.4%) had severe vitamin D deficiency. Patients with a 25-hydroxy vitamin D concentration <10 ng/ml had an increased risk of abdominal obesity (72.4% vs. 47.2%, P = 0.023) and a higher prevalence of metabolic syndrome (69% vs. 42.2%, P = 0.015) compared with patients with 25-hydroxy vitamin D levels >10 ng/ml. Although total energy and vitamin D intake were reduced during the program, serum 25-hydroxy vitamin D levels increased in patients with NAFLD (P < 0.001). Liver enzymes and metabolic parameters also improved, even as vitamin D intake decreased. Serum vitamin D concentration increased with body weight and intrahepatic fat reduction, independent of decreases in vitamin D intake.
  
  
  
  Weight loss per increased serum vitamin D level without vitamin D supplementation and improved metabolic parameters in NAFLD.
authors.affiliation: Department of Food and Nutrition, Sungshin Women's University, Seoul, Republic of Korea.
authors.forename: Seung Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Hanyang University School of Medicine, Seoul, Republic of Korea. Electronic address: noshin@hanyang.ac.kr.
authors.forename: Dae Won
authors.initials: DW
authors.lastname: Jun
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: choyk2004.cho@samsung.com.
authors.forename: Yong Kyun
authors.initials: YK
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Hanyang University School of Medicine, Seoul, Republic of Korea.
authors.forename: Ki Seol
authors.initials: KS
authors.lastname: Jang
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D031204:Caloric Restriction; D002784:Cholesterol / Q000097:blood; D019587:Dietary Supplements; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology*; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000097:blood* / Q000150:complications / Q000628:therapy; D056128:Obesity, Abdominal / Q000097:blood / Q000453:epidemiology; D015995:Prevalence; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D014466:Ultraviolet Rays; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D015431:Weight Loss; D061217:Weight Reduction Programs
chemical_list: D001786:Blood Glucose; D014807:Vitamin D; D002784:Cholesterol; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase
keywords: Non-alcoholic fatty liver disease; Sunlight exposure; Vitamin D