It is contained in preparations used for treatment of excessive gastric acidity, oral rehydration solutions and fluids for intravenous use that aim the correction of acute metabolic acidosis. Also used for long-standing treatment of chronic metabolic acidosis due to kidney malfunction. Oral bicarbonate solutions neutralize gastric acidity with production of Carbon Dioxide. The rest is absorbed by the gut. In the plasma, bicarbonate is kept at normal physiological range, with the excess eliminated by the kidney. Epithelial cells of the mammary gland regulate the entrance of sodium and bicarbonate into the mother's milk, with little effect on milk composition due to diet. Bicarbonate decreases secretion of Prolactin in cases of secondary Hyperprolactinemia due to metabolic acidosis, but does not affect production of the milk. WHO Model List of Essential Medicines (2002): compatible with breastfeeding