The Impact of Vitamin D in Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study in Patients with Morbid Obesity

Marta Borges-Canha,^1,2 João Sérgio Neves,^1,2 Fernando Mendonça,¹ Maria Manuel Silva,¹ Cláudia Costa,³ Pedro M Cabral,⁴ Vanessa Guerreiro,¹ Rita Lourenço,⁵ Patrícia Meira,⁵ Daniela Salazar,¹ Maria João Ferreira,¹ Jorge Pedro,¹ Ana Rita Leite,² Madalena von-Hafe,² Catarina Vale,² Sara Viana,¹ Ana Sande,¹ Sandra Belo,¹ Eva Lau,¹ Paula Freitas,^1,6 Davide Carvalho<sup>1,6

1</sup>Serviço de Endocrinologia, Diabetes e Metabolismo do Centro Hospitalar Universitário de São João, Porto, Portugal; ²Departamento de Cirurgia e Fisiologia, Faculdade de Medicina da Universidade do Porto, Porto, Portugal; ³Serviço de Endocrinologia do Instituto Português de Oncologia do Porto, Porto, Portugal; ⁴Serviço de Patologia Clínica do Centro Hospitalar Universitário Cova da Beira, Covilhã, Portugal; ⁵Faculdade de Ciências da Nutrição e Alimentação da Universidade do Porto, Porto, Portugal; ⁶Investigação e Inovação Em Saúde (I3s), Faculdade de Medicina da Universidade do Porto, Porto, Portugal

Correspondence: Marta Borges-Canha
Serviço de Endocrinologia, Diabetes e Metabolismo do Centro Hospitalar Universitário de São João, Alameda Prof. Hernâni Monteiro, Porto, 4200-319, Portugal
Tel +351918935390
Email marta.canha@gmail.com

Purpose: We aimed to evaluate the association between vitamin D status and hepatic function parameters and scores: Fatty Liver Index (FLI, predictor of hepatic steatosis) and BARD (BMI, AST/ALT ratio and DM, predictor of hepatic fibrosis) in patients with morbid obesity.
Patients and Methods: Cross-sectional study including patients with morbid obesity followed in our centre between January 2010 and July 2018. Patients with missing vitamin D levels or hepatic profile parameters were excluded. We divided the population according to two cut-offs of vitamin D levels (12ng/mL and 20ng/mL).
Results: The included population (n=1124) had an average age of 43.3± 10.7 years and 84.3% were female. Seventy-point eight percent of the population had vitamin D levels lower than 20ng/mL and 34.8% lower than 12ng/dL. Patients with lower vitamin D levels (< 12ng/mL) had higher BMI, hip and waist circumferences and higher prevalence of hypertension. Higher FLI scores [OR= 0.77 (0.07), p< 0.01] and ALP levels [β= − 0.03 (− 0.06, − 0.01), p< 0.01] associated to lower vitamin D levels.
Conclusion: Vitamin D deficiency is associated with a higher risk of hepatic steatosis in individuals with morbid obesity. Correction of vitamin D deficiency may have a beneficial role in the management of NAFLD in patients with morbid obesity.

Keywords: vitamin D, fatty liver, NAFLD, obesity