Hypo-/achlorhydria; iron and/or vitamin B12 insufficiency/deficiency; hypoghrelinemia; decreased production of gastric/gut estrogens and dopamine; increased gastrin, histamine and PTH production; alterations in serotonin levels; and gut dysbiosis may impair nutrients absorption, cause alterations in mineral metabolism (calcium, phosphate and magnesium) and stimulate bone degradation. This evidence concerns the gene GAST and hyperinsulinemic hypoglycemia, familial, 4.