Vitamins - Difference between calcium carbonate and calcium citrate

Difference between calcium carbonate and calcium citrate:
 
Calcium carbonate is found in antacids, such as Tums and Rolaids. Calcium carbonate neutralizes the acid in your stomach. An acidic environment is required to absorb calcium.  If calcium carbonate is taken, then the calcium will not be absorbed.  An acidic environment is also required in order to absorb vitamin D, which is essential for the uptake of calcium into the bones. So, by taking calcium carbonate, neither the calcium nor vitamin D are absorbed. This kind of non-absorption will prove to be detrimental to one's long-term health.  Many surgeons and dieticians do not recommend it, either.  It is for the same reason that antacids should not be taken continuously for more than 2 weeks.

Calcium citrate, on the other hand, is better because it does not neutralize the acid in your stomach. It is more readily absorbed and doesn't interfere with the absorption of vitamin D.  Therefore, it is highly recommended by surgeons and dieticians.

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