Ask A Scientist© General Science Archive

 

>
> >  name       Susan
> >  status     other
> >  age        40s
>
> >  Question - I am a 41 year old woman with a history of kidney stones. I
> > normally developed stones in pregnancy...my last being 1993. Six years
> > ago we installed a salt soft water system in our home. The unit uses rock
> > salt to remove the hardness from the water. This is my main source of
> > water intake. Four years ago I began to see an increase in stone
> > formation both in size and quanitity. The stones are calcium oxalate. I
> > am creating stones in both kidneys...endlessly. Medical conditions have
> > been ruled out. I watch my diet and salt intake.....but did not even
> > consider the rock salt that softens my water.....is there a correlation
> > between the water I drink and the increase of kidney stones? Any help I
> > would appreciate.
>
>Water softeners are ion exchangers, replacing the calcium and magnesium in
>the water with sodium. I don't know the biochemical processes that lead to
>formation of kidney stones. If salt intake is something you need to worry
>about, your water softener system might be part of the problem, as it does
>greatly increase the amount of sodium in your water.
>
>In general, soft water is necessary for soap to work properly, but not so
>much for health. As I mentioned, water softeners replace calcium and
>magnesium with sodium. Calcium and magnesium are not especially bad for
>health, and in fact are the ions that make mineral waters taste good. (In
>your case, since you have a tendency to develop calcium oxalate kidney
>stones, calcium might be something to be concerned about.) On the other
>hand, some people are sensitive to sodium. In such cases, drinking softened
>water is actually worse than drinking the incoming hard water.
>
>In summary, I know nothing about kidney stones. Ask your doctor what the
>expected effects of calcium and sodium intake are on people with a tendency
>to get kidney stones, recognizing that six years ago your calcium intake
>dropped and your sodium intake increased.
>
>Richard E. Barrans Jr., Ph.D.
>Assistant Director
>PG Research Foundation, Darien, Illinois
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