This post is an explanation of the how the kidney functions:

1, Elimination of waste, such as urea, uric acid, water-soluble toxins, and various neutralized chemicals like drugs.

2. Reabsorption of many organic molecules, electrolytes and minerals that were filtered but are still useful to the body.

3. Water excretion and reabsorption according to the body’s needs, i.e. water homeostasis and the maintenance of normal blood volumes and pressures.

4. Formation of active vitamin D (1,25 Dihydroxycholecalciferol) from 25 Hydroxycholecalciferol.

5. Secretion of renin, which activates the angiotensin-aldosterone axis for sodium and water reabsorption.

6. Acid-base balance. The kidneys correct a respiratory acidosis or alkalosis.