Relevance of vitamin D deficiency in patients with chronic autoimmune atrophic gastritis: A prospective study

Background: Chronic autoimmune atrophic gastritis (CAAG) is an autoimmune disease characterized by hypo/achlorhydria. A role of CAAG in the pathogenesis of nutritional deficiencies has been reported, therefore we hypothesized a possible association between CAAG and 25-OH-Vitamin D [25(OH)D] deficiency. Aim of the present study is to evaluate the prevalence of 25(OH)D deficiency in CAAG patients. Methods: 87 CAAG patients (71 females; mean age 63.5 ± 12.8 years) followed at our Centre from January 2012 to July 2015 were consecutively evaluated. 25(OH)D, vitamin B₁₂, parathormone, and calcium were measured in all the CAAG patients. The results were compared with a control group of 1232 healthy subjects. Results: In the CAAG group the mean 25(OH)D levels were significantly lower than in the control group (18.8 vs. 27.0 ng/ml, p < 0.0001). 25(OH)D levels < 20 ng/ml was observed in 57 patients, while levels < 12.5 ng/ml in 27 patients. A significant correlation between vitamin B₁₂ values at diagnosis and 25(OH)D levels was observed (r_s = 0.25, p = 0.01). Interestingly, the CAAG patients with moderate/severe gastric atrophy had lower 25(OH)D values as compared to those with mild atrophy (11.8 vs. 20 ng/ml; p = 0.0047). Moreover, the 25(OH)D levels were significantly lower in CAAG patients with gastric carcinoid as compared to those without gastric carcinoid (11.8 vs. 19.8 ng/ml; p = 0,0041). Conclusion: Data from the present study showed a significant reduction of 25(OH)D levels in CAAG patients and a possible impairment of vitamin D absorption in CAAG may be postulated. Any implication to the genesis of gastric carcinoids remains to be elucidated.