Vitamin D deficiency in non-alcoholic fatty liver disease: The chicken or the egg?
BACKGROUND & AIMS
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
Weight loss per increased serum vitamin D level without vitamin D supplementation and improved metabolic parameters in NAFLD.
['Lee|Seung Min|SM|', 'Jun|Dae Won|DW|', 'Cho|Yong Kyun|YK|', 'Jang|Ki Seol|KS|']
D000328:Adult D000410:Alanine Transaminase D001219:Aspartate Aminotransferases D001786:Blood Glucose D031204:Caloric Restriction D002784:Cholesterol D019587:Dietary Supplements D015444:Exercise D005260:Female D006801:Humans D008297:Male D024821:Metabolic Syndrome D008875:Middle Aged D065626:Non-alcoholic Fatty Liver Disease D056128:Obesity, Abdominal D015995:Prevalence D016032:Randomized Controlled Trials as Topic D012307:Risk Factors D014466:Ultraviolet Rays D014807:Vitamin D D014808:Vitamin D Deficiency D015431:Weight Loss D061217:Weight Reduction Programs
Vitamin D Non-alcoholic fatty liver disease Sunlight exposure