Most kidney stones are made up of calcium and oxalate.
Information about the causes, symptoms and treatment of kidney
stones can be found at The Kidney Stone Web Site, Kidney
Stones, and other web sites. Kidney stones occur in men more
than women, and may have a variety of causes including your
diet, your family genes, and other factors.
Doctors used to prescribe a low calcium diet for preventing
kidney stones. This approach makes little sense if you
understand how calcium is managed in the body. Calcium levels
in the blood are kept pretty steady by balancing the
absorption of calcium from diet and taking calcium from bones
when needed. Changing the amount of calcium in the diet causes
very little change in the blood level of calcium The kidney
filters substances from the blood, so changing the dietary
intake of calcium does not change the amount of calcium that
is filtered by the kidneys.
Perhaps the most important step you can take towards
preventing kidney stones is drinking 8 to 10 8 oz. Glasses of
water every day. Having enough water in your body will help to
reduce the concentration of calcium in the fluid that your
kidney filters. High concentrations of calcium and oxalate,
phosphate or other minerals are needed to form stones.
Another approach to preventing kidney stones in adults is
to eat calcium rich foods and avoid oxalates. This works in
two ways 1) reducing the amount of oxalate available, and 2)
if calcium is present in the diet with oxalate, then calcium
and oxalate bind in the intestine. This way, less calcium and
oxalate enter the blood so that oxalates are not available to
bind with calcium in the kidney. You should not use calcium
supplements unless you talk to your doctor.
Very high intakes of sodium and protein may cause kidney
stones. You should use little salt in cooking or at the table
and avoid many high sodium processed foods. See the low-sodium
diet section for more details. Most people should have 2
portions of protein foods per day. The portions should be
about the size of a deck of cards or a quarter-pound hamburger
after it is cooked.
High Oxalate Foods to Avoid
If you avoid the foods listed below you can reduce your
oxalate intake. If you eat a large amount of foods on this
other list, eating less may be helpful.
