The Role of Calcium in Kidney Stone Formation: Myths and Facts

Did you know that calcium stones are the most common type of stones (around 80%) of all kidney stones diagnosed in the Indian population?

If you go by the name, it’s obvious to think of calcium as the culprit. But the truth of the matter is that low calcium intake in your diet is the real reason for calcium stone formation.

So if you have been avoiding calcium supplements or dairy all your life to prevent kidney stones, don’t jump to any conclusions just yet.

Below we discuss the role of calcium in kidney stone formation and debunk some of the common myths associated with it.

First, let’s cover some basics!

What Are Calcium Stones?

Kidney stones are irregularly shaped clusters of crystals made from minerals, acids, and other substances, like calcium, oxalate, uric acid, and sodium in your urine. Over months or years, when there is a high concentration of oxalate, and phosphate in your urine and too little liquid, the substances start to stick together, forming calcium oxalate and calcium phosphate crystals or stones. Most calcium stones are in the form of calcium oxalate.

Also Read: The 5 Most Common Types of Kidney Stones & How to Avoid Them

Calcium oxalate stones

Oxalate is a natural substance that your liver produces or that is absorbed by your body from the foods you eat. Spinach, wheat bran, almonds, beets, chocolate and many other common foods that you eat on a daily basis are rich sources of oxalates.

When you eat these foods, your digestive system breaks them down and absorbs the required nutrients. The remaining waste products then travel to your kidneys and are removed through urine. If the amount of oxalate is too high in your urine and there is low urine volume, then over time, oxalate binds with calcium to form calcium oxalate crystals.

These small crystals can stick together and develop into larger stones. The longer they remain in your kidneys, the bigger they can grow. Larger stones can become blocked in your urinary tract and cause severe pain and other symptoms like nausea, vomiting, blood in urine, cloudy urine, etc.

“Ever had a run-in with the emergency room due to kidney stones? You should drink Krishna’s Patharchuradi Swaras, an Ayurvedic blend of natural herbs that helps dissolve stones and facilitates their easy removal via urine.”

Read More: Top Ayurvedic Remedies for Kidney Stones: Natural Solutions to Dissolve Stones

Does Calcium Lead to Kidney Stones? Debunking 4 Common Myths

Kidney Stone Myth 1: Eating a calcium-rich diet causes kidney stones

This is the biggest myth about kidney stone formation. Sometimes people stop consuming dairy products considering they are high in calcium and may cause kidney stones. In reality, your dietary calcium plays a huge role in preventing kidney stones, particularly calcium oxalate stones.

When you eat foods rich in calcium, it binds with oxalate in your intestines. This binding process reduces the absorption of oxalate into your bloodstream, leading to lower levels of oxalate in your urine. Since high urinary oxalate levels are a significant risk factor for stone formation, adequate calcium intake helps prevent kidney stones.

Though most kidney stones are made up of calcium, they are not caused by a calcium-rich diet, unless you are eating more than the recommended daily amount.

Kidney Stone Myth 2: Only People with High Calcium Levels Get Kidney Stones

Another common misconception is that only people who have high calcium levels in their urine are at risk for developing kidney stones. While high urinary calcium, or hypercalciuria, can indeed lead to stone formation, it is not the only factor at play.

Even a person who has normal calcium levels in the blood can develop kidney stones due to various factors, like dehydration and the presence of high amounts of oxalate, uric acid, and phosphate in the urine, regardless of calcium concentration.

So, the process of kidney stone formation is a combination of many factors and not just high calcium levels.

Kidney Stone Myth 3: Calcium Supplements Are Always Bad for Kidney Stones

Calcium is an essential mineral that your body requires for bone health. If it is insufficient, your bone health may worsen, and the risk of conditions like osteoporosis may increase as you age.

The daily calcium requirement is 1,000 mg for females under 50 years and men under 70 years. For females over 50 years and men over 70 years, the requirement increases to 1,200 mg per day.

If you are not taking enough of this essential mineral, your body will start taking it from your bones to maintain adequate levels in the blood. This causes excessive calcium secretion in urine, increasing the risk of stone formation.

So, supplements are not the culprit. They can be safe and beneficial when taken with meals. Why along with meals you ask?

Well, calcium in food binds with dietary oxalate and is excreted in stool, preventing absorption and crystal formation in urine. However, if calcium supplements are taken on their own without food, they don’t bind with oxalate in the intestines. As a result, both calcium and oxalate can enter the urine, increasing the risk of crystal and stone formation.

Kidney Stone Myth 4: Cutting Out Calcium-Rich Foods Prevents Stones

A common belief is that eliminating calcium-rich foods from the diet can help prevent kidney stones. However, this myth is misleading and can have negative consequences for kidney health.

Calcium plays a vital role in reducing the risk of kidney stones, particularly calcium oxalate stones, which are the most prevalent type. When you cut out dietary calcium, you actually increase the absorption of oxalate in the intestines. Higher oxalate levels can lead to increased urinary oxalate concentrations, raising the likelihood of stone formation.

Moreover, calcium-rich foods contribute to overall health, providing essential nutrients for bone strength and other bodily functions. Instead of eliminating calcium, focus on a balanced diet that includes adequate amounts of calcium along with other nutrients.

The food items that you should actually cut down to prevent kidney stones are salt and animal protein like red meat, chicken, eggs, fish, etc. High salt keeps calcium from being absorbed by your body and animal protein increases uric acid levels, increasing the risk of stone formation. In addition, high oxalate foods such as spinach, nuts, chocolate, wheat bran, etc should also be avoided.

The Key Takeaways

• Keep eating calcium-rich foods like dairy. This helps bind oxalates in your intestines, allowing them to exit your body through stool instead of forming stones in your urine.
• Don’t stop taking your calcium supplements, especially if your doctor has recommended them for bone health and menopausal symptoms.
• Always take calcium supplements with meals for better absorption.
• Drink 6-8 glasses of water a day, unless your doctor has advised otherwise.
• Limit salt intake to prevent calcium excretion in urine.