Poster Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2017

Can vitamin D improve liver enzymes in overweight or obese otherwise healthy individuals at risk of non-alcoholic fatty liver disease? Cross-sectional and interventional outcomes (#329)

Negar Naderpoor 1 2 , Aya Mousa 1 , Maximilian de Courten 3 , Robert Scragg 4 , Barbora de Courten 1 2
  1. Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
  2. Diabetes Unit, Monash Health, Melbourne , VIC
  3. Centre for Chronic Disease, Victoria University, Melbourne, Australia
  4. School of Population Health, The University of Auckland, Auckland , New Zealand

Background: Vitamin D deficiency is prevalent in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis1. However, there is limited and inconsistent data on the effect of vitamin D supplementation on hepatic enzymes, as surrogate markers for NAFLD2,3.

Methods: We examined the relationships between 25-hydroxyvitamin D (25(OH)D) and γ-glutamyl transferase (GGT), alanine aminotransferase (ALT), alkaline phosphatase (ALP) in 120 drug-naïve individuals with no history of liver disease. Additionally, a subgroup of 54 vitamin D-deficient overweight or obese individuals underwent a randomised double-blind trial to investigate the effect of vitamin D supplementation (100,000 loading dose of cholecalciferol followed by 4000IU daily for 16 weeks) on hepatic enzymes. Hepatic enzymes, anthropometric parameters, lipid profile, insulin sensitivity (hyperinsulinaemic-euglycaemic clamp, M-value) and hs-CRP were measured before and after the intervention. 

Results: In cross-sectional study, there were no significant differences in GGT, ALT and ALP between vitamin D categories (25(OH)D<25 nmol/L, 25-50nmol/L, and >50 nmol/L) and no relationships were found between these enzymes and 25(OH)D before and after adjustment for age, sex, BMI, WHR, and insulin sensitivity (all p>0.5). In the randomised trial, 25(OH)D concentrations increased from 31.4±12.6(mean ± SD) at baseline to 88.4± 21.0 nmol/L at follow-up in the vitamin D group (n=28). In the placebo group (n=26), there was no significant change in mean 25(OH)D concentration at follow-up(34.2±10.0 vs 36.1±15.3 nmol/L). Mean changes in GGT, ALT and ALP were not significantly different between vitamin D and placebo groups. Change in 25(OH)D concentration was not correlated with changes in GGT, ALT and ALP before and after adjustments for age and sex. 

Conclusion: Serum 25(OH)D concentrations were not related to hepatic enzymes in our cohort, and vitamin D supplementation had no effect on the levels of hepatic enzymes in vitamin D-deficient and overweight or obese, otherwise healthy individuals. Hence, vitamin D supplementation is unlikely to prevent incident NAFLD.