Re: Kidney Stones

[Guest guest]

In a message dated 5/1/2003 8:00:24 AM Pacific Daylight Time,

medcat2@... writes:

> I was wondering if anyone out there has any links to published

> information regarding a link between kidney stones and calcium

> carbonate.

- I hope the answer you were looking for is that calcium supplements

do not seem to have a direct causal effect on kidney stones. It seems that

abuse of calcium carbonate (in excess of 4,000 grams a day) was correlated,

the majority of studies showed that calcium supplementation decreased the

risk.

<A

HREF= " http://www.happyherbalist.com/research.htm#Kidney%20Stones " >http://www.hap\

pyherbalist.com/research.htm#Kidney%20Stones</A>

A Prospective Study of Dietary Calcium and Other Nutrients and the Risk of

Symptomatic Kidney Stones

C. Curhan, Walter C. Willett, B. Rimm, and Meir J. Stampfer

Background A high dietary calcium intake is strongly suspected of increasing

the risk of kidney stones. However, a high intake of calcium can reduce the

urinary excretion of oxalate, which is thought to lower the risk. The concept

that a higher dietary calcium intake increases the risk of kidney stones

therefore requires examination.Methods We conducted a prospective study of

the relation between dietary calcium intake and the risk of symptomatic

kidney stones in a cohort of 45,619 men, 40 to 75 years of age, who had no

history of kidney stones. Dietary calcium was measured by means of a

semiquantitative food-frequency questionnaire in 1986. During four years of

follow-up, 505 cases of kidney stones were documented. Results After

adjustment for age, dietary calcium intake was inversely associated with the

risk of kidney stones; the relative risk of kidney stones for men in the

highest as compared with the lowest quintile group for calcium intake was

0.56 (95 percent confidence interval, 0.43 to 0.73; P for trend, <0.001).

This reduction in risk decreased only slightly (relative risk, 0.66; 95

percent confidence interval, 0.49 to 0.90) after further adjustment for other

potential risk factors, including alcohol consumption and dietary intake of

animal protein, potassium, and fluid. Intake of animal protein was directly

associated with the risk of stone formation (relative risk for men with the

highest intake as compared with those with the lowest, 1.33; 95 percent

confidence interval, 1.00 to 1.77); potassium intake (relative risk, 0.49; 95

percent confidence interval, 0.35 to 0.68) and fluid intake (relative risk,

0.71; 95 percent confidence interval, 0.52 to 0.97) were inversely related to

the risk of kidney stones. Conclusions A high dietary calcium intake

decreases the risk of symptomatic kidney stones. .

Source Information From the Departments of Epidemiology (W.C.W., E.B.R.,

M.J.S.) and Nutrition (W.C.W.), Harvard School of Public Health; the Medical

Service, Renal Division, Brockton-West Roxbury Veterans Affairs Medical

Center (G.C.C.); and the Channing Laboratory, Department of Medicine, Harvard

Medical School and Brigham and Women's Hospital (G.C.C., W.C.W., M.J.S.) --

all in Boston.

*******************************************************************

<A

HREF= " http://www.oznet.ksu.edu/dp_fnut/_timely/calcium1.htm " >http://www.oznet.ks\

u.edu/dp_fnut/_timely/calcium1.htm</A>

" Can calcium supplements promote kidney stones? It's unlikely, according to

some new research that looked at the relationship between recommended amounts

of calcium and the likelihood of getting kidney stones. In fact, it appears

that just the opposite is true. It seems that calcium binds with oxalate to

form calcium oxalate in the intestine and prevents much of it from being

absorbed into the body. "

Liebman, , and Weiwen Chai. Effect of dietary calcium on urinary

oxalate excretion after oxalate loads. Amer J Clin Nutr. 65:1453-9. May 1997.

Shils, Maurice E. And Vernon R. Young. Modern Nutrition in Health and

Disease, 7th ed. Lea & Febiger, Philadelphia. Pp. 1597-98. 1988.

*****************************************************************

<A

HREF= " http://www.calciuminfo.com/prof/3_8.htm#6 " >http://www.calciuminfo.com/prof\

/3_8.htm#6</A>

" While the NIH Consensus Development Conference on Optimal Calcium Intake

cautioned those patients with a history of kidney stones and high urinary

calcium about increasing their calcium intake excessively, the report also

cited the large study showing a protective effect of higher calcium intake

against kidney stones8.

 Most recently, Drs. Curhan et al, authors of the 1993 prospective study,

published further data on calcium intake and stones.9 In this latest study,

the authors conducted an analysis among women participating in the Nurses

Health Study over a 12-year period who had no prior history of kidney stones.

They found that higher dietary calcium intake was correlated with fewer

kidney stones. FAMILY= " SANSSERIF " FACE= " Arial "

 Although those subjects taking calcium supplements had a slightly higher

risk of stones, the incidence was only 1 case of stones per 1,000 person

years. The authors propose that since 67% of women taking calcium supplements

took them between meals or with breakfast, a meal usually low in oxalate, the

calcium could not perform its role of blocking oxalate stone formation the

same way that calcium at meals is able to do.

 In a recently completed trial, only two cases of kidney stones were reported

in 2,295 women taking 2,000 mg of supplemental calcium carbonate per day.10

These results indicate that reduction of calcium intake is not advisable as a

way to reduce kidney stone risk, particularly given the other benefits of

adequate calcium intake, and that supplemental calcium may reduce kidney

stone risk if taken with meals. "

************************************************************

[Guest guest]

Of course, these studies were conducted on non-ops, presumably, people who have

normal amounts of hydrochloric acid in their stomachs and a pyloric valve to

make sure that the calcium carbonate has a run-in with such acid, stripping the

elemental calcium away from the carbonate. The studies were also probably not

concerned with the consumption of " brown " things -- tea, coffee, colas -- by

those people, a known risk-increaser for stones.

When considering this issue, I would also look at the anecdotal (but real)

wisdom of many people here who supplemented with calcium carbonate post-op,

developed stones, and on the advice of their urologists or people here, switched

to citrate, lowered their " brown " intake, and have suffered no further kidney

stone incidents.

I had a kidney stone once, while I was 6 months pregnant and taking an Rx

prenatal with 2000 mg of calcium as carbonate (the only time I've ever

consistently ingested carbonate for any length of time). Having birthed two

babies without drugs, the one at home weighing 8 pounds, 10 ounces, I'll take

childbirth any day over a kidney stone. Even if you include the first

little-sleep year with that baby! LOL I will never knowingly consume calcium

carbonate again in my life, in any quantity.

Ziobro

Open RNY 09/17/01

310/130

Http://tinyurl.com/4e3h my AMOS profile

Re: Kidney Stones

In a message dated 5/1/2003 8:00:24 AM Pacific Daylight Time,

medcat2@... writes:

> I was wondering if anyone out there has any links to published

> information regarding a link between kidney stones and calcium

> carbonate.

- I hope the answer you were looking for is that calcium supplements do

not seem to have a direct causal effect on kidney stones. It seems that abuse

of calcium carbonate (in excess of 4,000 grams a day) was correlated, the

majority of studies showed that calcium supplementation decreased the risk.

<A

HREF= " http://www.happyherbalist.com/research.htm#Kidney%20Stones " >http://www.hap\

pyherbalist.com/research.htm#Kidney%20Stones</A>

A Prospective Study of Dietary Calcium and Other Nutrients and the Risk of

Symptomatic Kidney Stones C. Curhan, Walter C. Willett, B. Rimm, and

Meir J. Stampfer Background A high dietary calcium intake is strongly suspected

of increasing the risk of kidney stones. However, a high intake of calcium can

reduce the urinary excretion of oxalate, which is thought to lower the risk. The

concept that a higher dietary calcium intake increases the risk of kidney stones

therefore requires examination.Methods We conducted a prospective study of the

relation between dietary calcium intake and the risk of symptomatic kidney

stones in a cohort of 45,619 men, 40 to 75 years of age, who had no history of

kidney stones. Dietary calcium was measured by means of a semiquantitative

food-frequency questionnaire in 1986. During four years of follow-up, 505 cases

of kidney stones were documented. Results After adjustment for age, dietary

calcium intake was inversely associated with the risk of kidney stones; the

relative risk of kidney stones for men in the highest as compared with the

lowest quintile group for calcium intake was

0.56 (95 percent confidence interval, 0.43 to 0.73; P for trend, <0.001).

This reduction in risk decreased only slightly (relative risk, 0.66; 95 percent

confidence interval, 0.49 to 0.90) after further adjustment for other potential

risk factors, including alcohol consumption and dietary intake of animal

protein, potassium, and fluid. Intake of animal protein was directly associated

with the risk of stone formation (relative risk for men with the highest intake

as compared with those with the lowest, 1.33; 95 percent confidence interval,

1.00 to 1.77); potassium intake (relative risk, 0.49; 95 percent confidence

interval, 0.35 to 0.68) and fluid intake (relative risk, 0.71; 95 percent

confidence interval, 0.52 to 0.97) were inversely related to the risk of kidney

stones. Conclusions A high dietary calcium intake decreases the risk of

symptomatic kidney stones. .

Source Information From the Departments of Epidemiology (W.C.W., E.B.R.,

M.J.S.) and Nutrition (W.C.W.), Harvard School of Public Health; the Medical

Service, Renal Division, Brockton-West Roxbury Veterans Affairs Medical Center

(G.C.C.); and the Channing Laboratory, Department of Medicine, Harvard Medical

School and Brigham and Women's Hospital (G.C.C., W.C.W., M.J.S.) -- all in

Boston.

*******************************************************************

<A

HREF= " http://www.oznet.ksu.edu/dp_fnut/_timely/calcium1.htm " >http://www.oznet.ks\

u.edu/dp_fnut/_timely/calcium1.htm</A>

" Can calcium supplements promote kidney stones? It's unlikely, according to some

new research that looked at the relationship between recommended amounts of

calcium and the likelihood of getting kidney stones. In fact, it appears that

just the opposite is true. It seems that calcium binds with oxalate to form

calcium oxalate in the intestine and prevents much of it from being absorbed

into the body. "

Liebman, , and Weiwen Chai. Effect of dietary calcium on urinary oxalate

excretion after oxalate loads. Amer J Clin Nutr. 65:1453-9. May 1997.

Shils, Maurice E. And Vernon R. Young. Modern Nutrition in Health and

Disease, 7th ed. Lea & Febiger, Philadelphia. Pp. 1597-98. 1988.

*****************************************************************

<A

HREF= " http://www.calciuminfo.com/prof/3_8.htm#6 " >http://www.calciuminfo.com/prof\

/3_8.htm#6</A>

" While the NIH Consensus Development Conference on Optimal Calcium Intake

cautioned those patients with a history of kidney stones and high urinary

calcium about increasing their calcium intake excessively, the report also cited

the large study showing a protective effect of higher calcium intake against

kidney stones8.

 Most recently, Drs. Curhan et al, authors of the 1993 prospective study,

published further data on calcium intake and stones.9 In this latest study, the

authors conducted an analysis among women participating in the Nurses Health

Study over a 12-year period who had no prior history of kidney stones.

They found that higher dietary calcium intake was correlated with fewer kidney

stones. FAMILY= " SANSSERIF " FACE= " Arial "

 Although those subjects taking calcium supplements had a slightly higher risk

of stones, the incidence was only 1 case of stones per 1,000 person years. The

authors propose that since 67% of women taking calcium supplements took them

between meals or with breakfast, a meal usually low in oxalate, the calcium

could not perform its role of blocking oxalate stone formation the same way that

calcium at meals is able to do.

 In a recently completed trial, only two cases of kidney stones were reported in

2,295 women taking 2,000 mg of supplemental calcium carbonate per day.10 These

results indicate that reduction of calcium intake is not advisable as a way to

reduce kidney stone risk, particularly given the other benefits of adequate

calcium intake, and that supplemental calcium may reduce kidney stone risk if

taken with meals. "

************************************************************