Ahmad, S.J., Ahmed, A.R., Ali, J., Macfaul, G., Johnson, M.W., Exadaktylos, A.K., Archid, R., Ahmad, S., Rostami-Nejad, M., Mohaghegh, H., Madhotra, R. and Rostami, K. 2020. The correlation between vitamin D levels and demographics in patients with gastrointestinal disorders; a cross-sectional study . Gastroenterology and Hepatology from Bed to Bench. 13, 3 (Jun. 2020), 223–231. DOI:https://doi.org/10.22037/ghfbb.v13i3.1649.