tea, calcium, stones

November 11, 2008 9:16 AM

Will drinking 4 cups a day of green tea, and taking calcium supplements with it give me kidney stones? From what I understand, most kidney stones are caused by oxalate (some in green tea) and calcium combining. But there is much confusion on the nets on this topic.
posted by parallax7d to health & fitness (8 comments total)

From my own life experience I have to say that your genetic susceptibility is going to matter more than anything else. I drink between 3 and 4 gallons of milk a week and a decent amount of tea, often green, on top of that (and have for most of my life). I have never had kidney stones. Ever. This guy I went to high school with cut almost all calcium and triggering foods out of his diet (and having only sort of known the guy I'm going to say he wasn't a tea drinker) and he was out every couple of months with terrible kidney stones. So I guess what I'm saying is, do you feel lucky, punk?
posted by phunniemee at 9:46 AM on November 11, 2008 [2 favorites has favorites]

Proper hydration helps as well...are you drinking anything other than those 4 cups of tea a day?
posted by cabingirl at 9:58 AM on November 11, 2008

I don't have a cite, but I think that the kind of calcium supplement you take will probably affect the outcome. There are lots of other mitigating factors as well so it's really not possible to accurately predict your exact situation here.
posted by Burhanistan at 10:21 AM on November 11, 2008

cabingirl - I usually drink about another 5-10 cups of water per day as well.

Burhanistan - What type of mitigating factors, like diet, exercise, family history?

Also if anyone has a Calcium + Vitamin D supplement they like please post it.
posted by parallax7d at 10:46 AM on November 11, 2008

From what I gathered from my step-father (he is like a kidney stone factory). Keeping properly hydrated is just about the most effective thing you can do to prevent them. The oxalates are harmless when sufficiently diluted. It is not until you get dried up that they become a serious issue.
posted by milqman at 12:38 PM on November 11, 2008

phunniemee is right. Will those cause kidney stones? Depends on if you're a stone-former. And that depends on genetics. If you have a stone, you'll have to figure out your triggers. But there are millions of people who drink green tea and take calcium who don't make stones.
posted by gramcracker at 12:54 PM on November 11, 2008

Sorry if it's a de-rail of sorts, but I'm 19 and have never had a kidney stone. Am I out of the woods for getting it at a young age statistically, since it sounds to be a genetic thing? I never really heard much about if they're common in the family. I don't have any male relatives (I'm under the impression they aren't as big a deal for women...) living nearby and it's not the sort of thing I'd like to bring up next family reunion.

Also, I've heard you'd be smart to keep your salt intake down and hydration up if you're worried about kidney stones.

Wikipedia says that you might actually be wise to take more calcium, possibly with your tea, as it increase the chances the compounds will crystallize in the intestine rather than the kidneys. If the stones form in the intestine, of course, it will leave within a stool, which is much easier to pass. It also seems to imply they're smaller crystals in the type of environment in a person's intestines rather than inside of urine.
posted by mccarty.tim at 1:51 PM on November 11, 2008

This is a great site for info in vitamins and minerals. There are also a couple of paragraphs on kidney stones on the linked page.
posted by sero_venientibus_ossa at 3:52 PM on November 11, 2008