Kidney stones are hardened masses of minerals that can develop in your kidneys. The most common types of kidney stones are those that contain calcium in some combination with oxalate and urate, two minerals found in your diet. While kidney stones may contain calcium, this does not mean you need to eliminate calcium-containing sources from your diet like milk.
Misconceptions
When you hear the words "calcium stone," it can be easy to conclude your stone is a result of calcium consumption in your diet. However, it's the environment in your kidneys that is likely causing the stones to form. For example, your kidneys work to maintain a urinary pH balance of about neutral. However, your urine can become too acidic, which allows kidney stones to form more easily. Also, you can get kidney stones when your body overproduces a hormone called parathormone, which is unrelated to your calcium intake.
Milk and Bioavailability
If you are prone to developing calcium kidney stones, milk can be a particularly good choice compared to other dietary sources like spinach and kale. This is because the calcium in milk is highly bioavailable, meaning the body easily absorbs it. As a result, minimal waste that could contribute to kidney stones is passed through the kidneys.
Acidic Environment
Some of the contributing factors to an acidic environment that causes calcium kidney stones to develop include a diet high in salt. Excess salt can cause calcium from food sources to remain in your kidneys longer, which increases your risk for kidney stones. Another factor is lack of citrate in your diet. Citrate can make your urine more alkaline -- the opposite of acidic. Incorporate citrate by consuming citrus fruits and drinks like lemonade and orange juice. Also, foods high in potassium can increase your urine's alkalinity. Fruits and vegetables tend to be high in potassium and can reduce your risk for developing kidney stones.
Food Intake Vs. Supplements
While calcium intake via milk and other dairy sources does not increase your risk for developing kidney stones, calcium supplementation is associated with an increased chance for kidney stones, according to the Dairy Council of California. To reduce your risk, take a supplement that does not cause you to go over the daily recommended limit of 2,500 mg per day, if you are between the ages of 19 and 50, or 2,000 mg per day if you are older than age 50. Remember to incorporate your intake from food sources like milk into this calculation.
