(b)
| No. | First Author, Year | Form of Vitamin D Used in the Study | Key Findings | Ref. No. |
|---|---|---|---|---|
| 1 | Paterson C. (1965) | 1α,25(OH)2D3 | Gastrectomy and other surgeries of the stomach can trigger osteomalacia due to the increased levels of serum vitamin D which results in increased absorption of calcium by the small intestine. | [150] |
| 2 | Kimura K. (1967) | 1α,25(OH)2D3 | Calcium deposits were found in the soft tissues of a patient who died of uremia after administration of toxic levels of Vitamin D for 6 months | [151] |
| 3 | Lawrence, W. (1977) | 1α,25(OH)2D3 | Inadequate absorption of Vitamin D in patients who underwent gastrectomy is due to steatorrhea which may contribute to osteomalacia later on. | [152] |
| 4 | Giovannucci E. (2006) | 1α,25(OH)2D3 | Black men with poor vitamin D status are highly susceptible for digestive system cancer and have a higher mortality rate. | [153] |
| 5 | Chen W. (2007) | 25(OH)D | A direct association between higher serum 25(OH)D concentration and increased risk of oesophageal squamous cell carcinomas (ESCC) in men but not women but no association with risk of gastric cardia or noncardia adenocarcinoma in either sex. | [154] |
| 6 | Pan L. (2010) | 1α,25(OH)2D3 | Studies in HGC-27 adenocarcinoma cells showed that Vitamin D can be used in gastric cancer therapies in association with trichostatin A ⁄ sodium butyrate and 5-aza-2-deoxycytidine | [155] |
| 7 | Antico A. (2012) | 1,25(OH)2D | Low vitamin D concentration in H. pylori gastritis patients might lead to a more severe Th1-type aggression to the stomach epithelium | [156] |
| 8 | Park M.R. (2012) | Paricalcitol (19-nor-1,25-(OH)2D2) | Paricalcitol, has anticancer activity on GC cells by regulating cell cycle, apoptosis and inflammation | [157] |
| 9 | Kopic S. (2013) | 1α,25(OH)2D3 | Gastric acid, gastrin secretion is increased in humans under conditions of hyperparathyroidism with the combined actions of both PTH and vitamin D | [158] |
| 10 | Guo L. (2014) | 1α,25(OH)2D3 | VDR and CAMP expression is up-regulated in the gastric epithelium during H. pylori infection; thus, VDR is important in maintaining the homeostasis of gastric mucosa and protection from H. pylori infection. | [159] |
| 11 | Wen Y (2015) | 1,25(OH)2D3 | VDR expression was seen to decline from the premalignant stage, to low expression in gastric cancer tissues. VDR could be a potential prognostic factor for patients with gastric cancer. | [160] |
| 12 | Bashir M. (2016) | 1α,25(OH)2D3 | Vitamin D influences the composition of gut microbiome. | [161] |
| 13 | Vyas N. (2016) | 25(OH)D | There is a positive relationship between VDD and gastric adenocarcinoma | [162] |
| 14 | Du C. (2017) | 1α,25(OH)2D3 | Vitamin D supplement might be a safe and economical way to prevent or treat gastric cancer | [163] |
| 15 | Yildirim O. (2017) | 25(OH)D | Deficiency of 25(OH)D may be a risk factor related to eradication failure of H. pylori, and supplementation of 25(OH)D before eradication of H. pylori may provide better results. | [164] |
| 16 | El Shahawy M.S. (2018) | 25(OH)D3 | 25(OH)D deficiency can be a risk factor in eradication failure of H. pylori infection. | [165] |
| 17 | Fletcher J. (2019) | 1α,25(OH)2D | 1α,25(OH)2D protects the gastrointestinal barrier and evokes immune responses | [166] |