By the way, doctor: How long does calcium absorption take?

Published: March, 2014

Q. I've read that the body can't assimilate more than 500 milligrams (mg) of calcium at a time. How long does this take? I want to allow enough time between taking my 500-mg calcium supplement and drinking a glass of milk.

A. The body can absorb a 500-mg dose of calcium very efficiently — whether from diet or supplements. But as the dose increases above that level, absorption efficiency declines. For example, the body doesn't absorb much more calcium from a single 1,000-mg dose than it does from a single 500-mg dose.

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