PDA

View Full Version : calcium....blocks absorption of vitamins?

golfbobbyhill
02-16-2003, 08:28 PM
A buddy of mine claims that calcium can block the absorption of vitamins?

Any truth to this?
AstronautJones
02-16-2003, 09:12 PM
Calcium can block the absorption of some vitamins like zinc. It doesn't block/slow absorption of all vitamins though, otherwise they wouldn't put it in multivitamins.
gettinjackT
02-17-2003, 01:31 PM
It will fight for absorption with some minerals, such as zinc and magnesium, but not to a very significant degree.
restless
02-17-2003, 01:54 PM
Originally posted by gettinjackT
It will fight for absorption with some minerals, such as zinc and magnesium, but not to a very significant degree.

Yes, it can compete with some minerals, but not with vitamins (zinc is not a vitamin, by the way). I know that with magnesium this only happens with a dosage of more than one gram of calcium and in the presence of phytate (present in whole grains mainly).