Stomach acid levels heavily interact synergistically with iron and manganese, whereby the absorption of both elements is enhanced by higher HCl acid levels, while an increase in iron or manganese will generally, but not always, result in raised stomach acid levels. Since Calcium and Magnesium have the exact opposite effect on stomach acid levels, their interaction with iron and manganese have a major impact on medical situations that are associated with raised or lowered stomach acid levels... Full Text