In addition to age and calcium Carbonate type, other factors that can affect calcium absorption include the dosage administered, stomach pH, patient size, oestrogen status, vitamin D level, and genetic polymorphisms.

When taken with food, 500 mg has the largest fractional absorption because the stomach is acidic. When a person has enough vitamin D, is healthy in terms of their absorption, is youthful, has more oestrogen, and has a greater body size, fractional absorption also rises. If someone has an achlorhydric condition or a mucosal lining problem, their ability to absorb calcium Carbonate is reduced. The body stores calcium mostly in its bones and teeth.

However, the majority of the calcium is present in the blood in the ionised, physiologically active form. The usual pharmacokinetic definition of metabolism does not apply to calcium Carbonate. Unabsorbed calcium Carbonate is expelled in the faeces, along with carbon dioxide from the lungs and urine, which are all influenced by glomerular filtration and renal tubule reabsorption under the regulation of parathyroid hormone (PTH) and vitamin D.

Read More  - http://wordoid01.weebly.com/cmi-article/when-carbon-dioxide-or-carbonic-acid-condenses-with-hydroxyl-molecules-a-diester-derivative-known-as-a-carbonate-is-produced