The high rates of gastroduodenal ulcers in hyperparathyroidism patients are linked to gastric hyperacidity from high calcium levels.
A study with 40 patients showed that higher serum calcium levels correlated with increased gastrin but not with gastric acid secretion.
The findings suggest that gastric hyperacidity is not a feature of parathyroid adenomas, possibly due to an inhibitory mechanism on gastrin, potentially involving calcitonin.