Calcium Citrate vs. Calcium Carbonate

Jan 26, 2009

After RNY our pouch no longer produces gastric acid (scientifically known as hydrocloric acid).  And after surgery most surgeons have their patients take a proton pump inhibitor for several weeks/months after surgery to "kill of" any remaining acid producing cells that might cause ulcers.  I took Prevacid for 12 months post-op. 

The diagnosis for lack of gastric acid in a patients stomach is called Achlorhydria.  This disorder is often seen in elderly patients, but since WLS has become increasingly popular, doctors have recognized that RNY patients need the same alternative treatment as elderly patients who have the same diagnosis.  

Calcium carbonate requires gastric acid in order to break down and be used by the body.   It does not break down in a neutral pH environment -- meaning it is not water soluable, it requires a highly acid environment to be bioavailable.

Calcium citrate is water soluable and dissolves quickly and easily in a neutral pH environment.  No acid is required.  In fact, a calcium citrate supplement tablet will dissolve in plain water in about 5 to 10 minutes.

In 1985 R. R. Recker published a study in the New England Journal of Medicine that showed the absorption rates of calcium carbonate vs. calcium citrate in patients with normal stomach acid vs. patients with achlorhydria.  Patients with achlorhydria absorbed calcium carbonate at a rate of 4% and absorbed calcium citrate at a rate of 45%.  Patients with normal hydrochloric acid levels absorbed calcium (either type) at about the same rate with no significant difference in absorption.

So what does all this mean?

It means that after RNY we must use calcium citrate as our calcium supplementation.  Calcium carbonate does not dissolve and is not used by our body after WLS.  The ASMBS Guidelines for Bariatric Nutrition recommends we take 1500-2000mg of calcium citrate supplement per day in addition to whatever calcium we get from food.  It is common knowledge among the medical community that doses of calcium must be no larger than 400-500mg at a time, spaced at least 2 hours apart.

Tums, Viactiv, Caltrate and the generic versions of all these brands..... all are calcium carbonate.  Stay away from them.  Look for Citracal, Bariatric Advantage, UpCalD, TwinLabs Calcium Citrate and others. Read the label carefully not only for the type of calcium, but also for the serving size.  Many calcium citrate brands require 2 pills per dose, so do the math according to your daily requirements.  For instance, Citracal Petites have 200mg calcium per pill... so to get 2000mg of calcium per day you'll need 10 pills in 5 doses throughout the day. 

My mom had RNY 5.5 years ago.  She was never taught the difference between calcium carbonate and calcium citrate.  She was simply told to "take calcium" -- not even told a certain amount per day, just to take the supplement.   She took calcium carbonate.  This past year she was diagnosed with osteoporosis with an 18.1% bone density loss in her spine.  She is only 54 years old and faces a very difficult road ahead with brittle bones, fractures and dental problems.  I preach about calcium so passionately because I don't want any other WLS patient to be faced with the same fate.

~Pam

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