As you’ve discussed in previous posts, phosphoric acid, caffeine, and sodium inhibit calcium absorption and/or promote calcium excretion.
Guidelines state that the body can only utilize 500 mg of calcium at a time.
That said, would extra calcium (beyond 500 mg) at a meal blunt the detrimental effects of phosphorus, caffeine, and sodium that are consumed concurrently?
– Megan Smith
Lubbock, TX
Great question!
In theory, yes, extra calcium would blunt the effects of the components you mention.
Semantics is key here. The body can utilize 500 milligrams of absorbable calcium.
A cup of cooked spinach, for example, contains 245 milligrams of calcium. Due to spinach’s high oxalic acid content, only five percent of that calcium (12 milligrams) are absorbed.
Hence, someone would need to eat 41 cups of spinach (10,045 milligrams of its calcium) to get 500 milligrams of absorbable calcium.
So, technically speaking, extra calcium does blunt the effects. However, once the body absorbs 500 “true” milligrams of calcium, extra milligrams become irrelevant.