On 2016 Sep 24, azita Hekmatdoost commented:

Comments on “No effects of oral vitamin D supplementation on non-alcoholic fatty liver disease in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial”

Makan Cheraghpour1,a ; Alireza Ghaemi 2,a ; and Azita Hekmatdoost 3* 1 Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran 2 Department of Basic Sciences and Nutrition, Health Sciences Research Center, School of Public Health, Mazandaran University of Medical Sciences, Sari, IR Iran 3 Department of Clinical Nutrition, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran *Corresponding Author: Azita Hekmatdoost, Department of Clinical Nutrition, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran a These two authors have equally contributed to this work.

Barchetta et al (1) recently reported that vitamin D supplementation for 24 weeks had no effect on non-alcoholic fatty liver disease in patients with type 2 diabetes. The results showed that consumption of high dose vitamin D lead to no significant changes in metabolic and cardiovascular parameters and hepatic steatosis in these patients. Considering the contradiction between these results and previous studies (2-9), we decided to point some overlooked points of this study despite the outstanding ones.<br> First, NAFLD is now one of the most common chronic diseases in the world and there is a direct link between the disease and other metabolic disorders such as obesity, type 2 diabetes and cardiovascular diseases (10). It seems that lifestyle plays an important role in the formation and progression of the disease, which shows wide variations due to changes in diet and lifestyle (11-12). In studies about patients with NAFLD evaluating the diet and its components such as energy, processed meat, total fat, trans/saturated -fatty acids, the type of carbohydrates is essential because any change in using them can be a potentially confounding factor in the results of this kind of studies (13-19). However, dietary intakes were not assessed in this study, and the study participants did not get any dietary recommendation at baseline to reduce this confounding factor. Second, many studies have shown that physical activity can lead to significant improvements in metabolic parameters and liver steatosis in patients with NAFLD (11). This confounding factor was dissembled in this study because it was not assessed during the study and there was no recommendation to the patients in this regard. Thirdly, sunlight is one of the most important sources of vitamin D in the human body, so that exposure to the sun can supply the daily requirement of vitamin D. There is no assessment of this variable in this study to overcome its effect as a confounding factor. Finally, we recommend making a revision of this study because vitamin D is a cheap and safe supplement and acceptable for most patients. Thus, vitamin D supplementation for treatment or prevention of metabolic diseases such as NAFLD may be useful for health and well-being of society. More researches are needed in this area. References 1. Barchetta I, Del Ben M, Angelico F, Di Martino M, Fraioli A, La Torre G, et al. No effects of oral vitamin D supplementation on non-alcoholic fatty liver disease in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial. BMC Med. 2016;14:92. 2. Chung GE, Kim D, Kwak MS, Yang JI, Yim JY, Lim SH, et al. The serum vitamin D level is inversely correlated with nonalcoholic fatty liver disease. Clin Mol Hepatol. 2016 Mar;22(1):146-51. 3. Foroughi M, Maghsoudi Z, Askari G. The effect of vitamin D supplementation on blood sugar and different indices of insulin resistance in patients with non-alcoholic fatty liver disease (NAFLD). Iran J Nurs Midwifery Res. 2016 Jan-Feb;21(1):100-4. 4. Leung PS. The Potential Protective Action of Vitamin D in Hepatic Insulin Resistance and Pancreatic Islet Dysfunction in Type 2 Diabetes Mellitus. Nutrients. 2016 Mar;8(3):147. 5. Luger M, Kruschitz R, Kienbacher C, Traussnigg S, Langer FB, Schindler K, et al. Prevalence of Liver Fibrosis and its Association with Non-invasive Fibrosis and Metabolic Markers in Morbidly Obese Patients with Vitamin D Deficiency. Obes Surg. 2016 Mar 17. 6. Mohamed Ahmed A, Abdel Ghany M, Abdel Hakeem GL, Kamal A, Khattab R, Abdalla A, et al. Assessment of Vitamin D status in a group of Egyptian children with non alcoholic fatty liver disease (multicenter study). Nutr Metab (Lond). 2016;13:53. 7. Nelson JE, Roth CL, Wilson LA, Yates KP, Aouizerat B, Morgan-Stevenson V, et al. Vitamin D Deficiency Is Associated With Increased Risk of Non-alcoholic Steatohepatitis in Adults With Non-alcoholic Fatty Liver Disease: Possible Role for MAPK and NF-kappaB? Am J Gastroenterol. 2016 Jun;111(6):852-63. 8. Wang D, Lin H, Xia M, Aleteng Q, Li X, Ma H, et al. Vitamin D Levels Are Inversely Associated with Liver Fat Content and Risk of Non-Alcoholic Fatty Liver Disease in a Chinese Middle-Aged and Elderly Population: The Shanghai Changfeng Study. PLoS One. 2016;11(6):e0157515. 9. Zhai HL, Wang NJ, Han B, Li Q, Chen Y, Zhu CF, et al. Low vitamin D levels and non-alcoholic fatty liver disease, evidence for their independent association in men in East China: a cross-sectional study (Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China)). Br J Nutr. 2016 Apr;115(8):1352-9. 10. Eslamparast T, Eghtesad S, Poustchi H, Hekmatdoost A. Recent advances in dietary supplementation, in treating non-alcoholic fatty liver disease. World journal of hepatology. 2015 Feb 27;7(2):204-12. 11. Ghaemi A, Taleban FA, Hekmatdoost A, Rafiei A, Hosseini V, Amiri Z, et al. How Much Weight Loss is Effective on Nonalcoholic Fatty Liver Disease? Hepat Mon. 2013;13(12):e15227. 12. Hekmatdoost A, Shamsipour A, Meibodi M, Gheibizadeh N, Eslamparast T, Poustchi H. Adherence to the Dietary Approaches to Stop Hypertension (DASH) and risk of Nonalcoholic Fatty Liver Disease. Int J Food Sci Nutr. 2016 Jul 19:1-6. 13. Eslamparast T, Poustchi H, Zamani F, Sharafkhah M, Malekzadeh R, Hekmatdoost A. Synbiotic supplementation in nonalcoholic fatty liver disease: a randomized, double-blind, placebo-controlled pilot study. Am J Clin Nutr. 2014 Mar;99(3):535-42. 14. Faghihzadeh F, Adibi P, Hekmatdoost A. The effects of resveratrol supplementation on cardiovascular risk factors in patients with non-alcoholic fatty liver disease: a randomised, double-blind, placebo-controlled study. Br J Nutr. 2015 Sep 14;114(5):796-803. 15. Faghihzadeh F, Adibi P, Rafiei R, Hekmatdoost A. Resveratrol supplementation improves inflammatory biomarkers in patients with nonalcoholic fatty liver disease. Nutr Res. 2014 Oct;34(10):837-43. 16. Rahimlou M, Yari Z, Hekmatdoost A, Alavian SM, Keshavarz SA. Ginger Supplementation in Nonalcoholic Fatty Liver Disease: A Randomized, Double-Blind, Placebo-Controlled Pilot Study. Hepat Mon. 2016 Jan;16(1):e34897. 17. Shavakhi A, Minakari M, Firouzian H, Assali R, Hekmatdoost A, Ferns G. Effect of a Probiotic and Metformin on Liver Aminotransferases in Non-alcoholic Steatohepatitis: A Double Blind Randomized Clinical Trial. Int J Prev Med. 2013 May;4(5):531-7. 18. Yari Z, Rahimlou M, Eslamparast T, Ebrahimi-Daryani N, Poustchi H, Hekmatdoost A. Flaxseed supplementation in non-alcoholic fatty liver disease: a pilot randomized, open labeled, controlled study. Int J Food Sci Nutr. 2016 Jun;67(4):461-9. 19. Askari F, Rashidkhani B, Hekmatdoost A. Cinnamon may have therapeutic benefits on lipid profile, liver enzymes, insulin resistance, and high-sensitivity C-reactive protein in nonalcoholic fatty liver disease patients. Nutr Res. 2014 Feb;34(2):143-8.

On 2016 Sep 24, azita Hekmatdoost commented:

Comments on “No effects of oral vitamin D supplementation on non-alcoholic fatty liver disease in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial”

Makan Cheraghpour1,a ; Alireza Ghaemi 2,a ; and Azita Hekmatdoost 3* 1 Nutrition and Metabolic Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran 2 Department of Basic Sciences and Nutrition, Health Sciences Research Center, School of Public Health, Mazandaran University of Medical Sciences, Sari, IR Iran 3 Department of Clinical Nutrition, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran *Corresponding Author: Azita Hekmatdoost, Department of Clinical Nutrition, Faculty of Nutrition and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran a These two authors have equally contributed to this work.

Barchetta et al (1) recently reported that vitamin D supplementation for 24 weeks had no effect on non-alcoholic fatty liver disease in patients with type 2 diabetes. The results showed that consumption of high dose vitamin D lead to no significant changes in metabolic and cardiovascular parameters and hepatic steatosis in these patients. Considering the contradiction between these results and previous studies (2-9), we decided to point some overlooked points of this study despite the outstanding ones.<br> First, NAFLD is now one of the most common chronic diseases in the world and there is a direct link between the disease and other metabolic disorders such as obesity, type 2 diabetes and cardiovascular diseases (10). It seems that lifestyle plays an important role in the formation and progression of the disease, which shows wide variations due to changes in diet and lifestyle (11-12). In studies about patients with NAFLD evaluating the diet and its components such as energy, processed meat, total fat, trans/saturated -fatty acids, the type of carbohydrates is essential because any change in using them can be a potentially confounding factor in the results of this kind of studies (13-19). However, dietary intakes were not assessed in this study, and the study participants did not get any dietary recommendation at baseline to reduce this confounding factor. Second, many studies have shown that physical activity can lead to significant improvements in metabolic parameters and liver steatosis in patients with NAFLD (11). This confounding factor was dissembled in this study because it was not assessed during the study and there was no recommendation to the patients in this regard. Thirdly, sunlight is one of the most important sources of vitamin D in the human body, so that exposure to the sun can supply the daily requirement of vitamin D. There is no assessment of this variable in this study to overcome its effect as a confounding factor. Finally, we recommend making a revision of this study because vitamin D is a cheap and safe supplement and acceptable for most patients. Thus, vitamin D supplementation for treatment or prevention of metabolic diseases such as NAFLD may be useful for health and well-being of society. More researches are needed in this area. References 1. Barchetta I, Del Ben M, Angelico F, Di Martino M, Fraioli A, La Torre G, et al. No effects of oral vitamin D supplementation on non-alcoholic fatty liver disease in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial. BMC Med. 2016;14:92. 2. Chung GE, Kim D, Kwak MS, Yang JI, Yim JY, Lim SH, et al. The serum vitamin D level is inversely correlated with nonalcoholic fatty liver disease. Clin Mol Hepatol. 2016 Mar;22(1):146-51. 3. Foroughi M, Maghsoudi Z, Askari G. The effect of vitamin D supplementation on blood sugar and different indices of insulin resistance in patients with non-alcoholic fatty liver disease (NAFLD). Iran J Nurs Midwifery Res. 2016 Jan-Feb;21(1):100-4. 4. Leung PS. The Potential Protective Action of Vitamin D in Hepatic Insulin Resistance and Pancreatic Islet Dysfunction in Type 2 Diabetes Mellitus. Nutrients. 2016 Mar;8(3):147. 5. Luger M, Kruschitz R, Kienbacher C, Traussnigg S, Langer FB, Schindler K, et al. Prevalence of Liver Fibrosis and its Association with Non-invasive Fibrosis and Metabolic Markers in Morbidly Obese Patients with Vitamin D Deficiency. Obes Surg. 2016 Mar 17. 6. Mohamed Ahmed A, Abdel Ghany M, Abdel Hakeem GL, Kamal A, Khattab R, Abdalla A, et al. Assessment of Vitamin D status in a group of Egyptian children with non alcoholic fatty liver disease (multicenter study). Nutr Metab (Lond). 2016;13:53. 7. Nelson JE, Roth CL, Wilson LA, Yates KP, Aouizerat B, Morgan-Stevenson V, et al. Vitamin D Deficiency Is Associated With Increased Risk of Non-alcoholic Steatohepatitis in Adults With Non-alcoholic Fatty Liver Disease: Possible Role for MAPK and NF-kappaB? Am J Gastroenterol. 2016 Jun;111(6):852-63. 8. Wang D, Lin H, Xia M, Aleteng Q, Li X, Ma H, et al. Vitamin D Levels Are Inversely Associated with Liver Fat Content and Risk of Non-Alcoholic Fatty Liver Disease in a Chinese Middle-Aged and Elderly Population: The Shanghai Changfeng Study. PLoS One. 2016;11(6):e0157515. 9. Zhai HL, Wang NJ, Han B, Li Q, Chen Y, Zhu CF, et al. Low vitamin D levels and non-alcoholic fatty liver disease, evidence for their independent association in men in East China: a cross-sectional study (Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China)). Br J Nutr. 2016 Apr;115(8):1352-9. 10. Eslamparast T, Eghtesad S, Poustchi H, Hekmatdoost A. Recent advances in dietary supplementation, in treating non-alcoholic fatty liver disease. World journal of hepatology. 2015 Feb 27;7(2):204-12. 11. Ghaemi A, Taleban FA, Hekmatdoost A, Rafiei A, Hosseini V, Amiri Z, et al. How Much Weight Loss is Effective on Nonalcoholic Fatty Liver Disease? Hepat Mon. 2013;13(12):e15227. 12. Hekmatdoost A, Shamsipour A, Meibodi M, Gheibizadeh N, Eslamparast T, Poustchi H. Adherence to the Dietary Approaches to Stop Hypertension (DASH) and risk of Nonalcoholic Fatty Liver Disease. Int J Food Sci Nutr. 2016 Jul 19:1-6. 13. Eslamparast T, Poustchi H, Zamani F, Sharafkhah M, Malekzadeh R, Hekmatdoost A. Synbiotic supplementation in nonalcoholic fatty liver disease: a randomized, double-blind, placebo-controlled pilot study. Am J Clin Nutr. 2014 Mar;99(3):535-42. 14. Faghihzadeh F, Adibi P, Hekmatdoost A. The effects of resveratrol supplementation on cardiovascular risk factors in patients with non-alcoholic fatty liver disease: a randomised, double-blind, placebo-controlled study. Br J Nutr. 2015 Sep 14;114(5):796-803. 15. Faghihzadeh F, Adibi P, Rafiei R, Hekmatdoost A. Resveratrol supplementation improves inflammatory biomarkers in patients with nonalcoholic fatty liver disease. Nutr Res. 2014 Oct;34(10):837-43. 16. Rahimlou M, Yari Z, Hekmatdoost A, Alavian SM, Keshavarz SA. Ginger Supplementation in Nonalcoholic Fatty Liver Disease: A Randomized, Double-Blind, Placebo-Controlled Pilot Study. Hepat Mon. 2016 Jan;16(1):e34897. 17. Shavakhi A, Minakari M, Firouzian H, Assali R, Hekmatdoost A, Ferns G. Effect of a Probiotic and Metformin on Liver Aminotransferases in Non-alcoholic Steatohepatitis: A Double Blind Randomized Clinical Trial. Int J Prev Med. 2013 May;4(5):531-7. 18. Yari Z, Rahimlou M, Eslamparast T, Ebrahimi-Daryani N, Poustchi H, Hekmatdoost A. Flaxseed supplementation in non-alcoholic fatty liver disease: a pilot randomized, open labeled, controlled study. Int J Food Sci Nutr. 2016 Jun;67(4):461-9. 19. Askari F, Rashidkhani B, Hekmatdoost A. Cinnamon may have therapeutic benefits on lipid profile, liver enzymes, insulin resistance, and high-sensitivity C-reactive protein in nonalcoholic fatty liver disease patients. Nutr Res. 2014 Feb;34(2):143-8.