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.

• Chocolate
• Tea
• Spinach
• Beet tops
• Peanuts
• Almonds
• Pecans

High Calcium Foods to Choose
Many other foods may be good sources of calcium, but those listed below are sources that are commonly available and many people may like to use.

• Skim or 1% milk
• Low-fat yogurt
• Low-fat cheeses

• 2% milk
• 2%milk cheeses
• Low-fat yogurt
• Tofu or soy milk (choose calcium processed products-look at the label)
• Calcium Fortified fruit juices
• Sesame Seeds

Use these sources of calcium as part of a balanced diet as recommended by the United States Department of Agriculture's Food Guide Pyramid and the Dietary Guidelines for Americans. The chart below shows that foods with higher fat are often lower in calcium than lower fat products. Read labels to look for calcium content.