Nutrition Diet: What foods cause kidney stones in children?

October 25, 2025 •

4 min read

With a rising incidence of pediatric kidney stone cases, many parents are concerned. Understanding what foods cause kidney stones in children? is the first step toward prevention and better diet management. A child's diet plays a significant role in determining their risk, primarily through influencing urine composition.

Quick Summary

Certain foods increase the risk of kidney stones in children, including high-oxalate items, excessive sodium, and added sugars, which lead to higher levels of stone-forming substances in the urine.

Key Points

High Sodium: Excessive salt, often found in processed foods and fast food, increases urinary calcium and the risk of stones.
High Oxalate: Foods like spinach, nuts, and chocolate contain oxalate, which can form stones when not properly balanced with dietary calcium.
Added Sugars: Sugary drinks and high-fructose corn syrup can lead to higher urinary calcium and decreased urine volume, increasing stone risk.
Excess Animal Protein: Too much animal protein, especially red meat and organ meats, can make urine more acidic and promote stone formation.
Hydration is Key: Drinking plenty of water is the most important preventive measure, as it dilutes urine and prevents crystal buildup.
Don't Restrict Calcium: Adequate dietary calcium is protective against calcium oxalate stones by binding to oxalate in the gut, but it's best obtained from food rather than supplements.

The Rising Concern of Pediatric Kidney Stones

Kidney stones, once considered an ailment primarily affecting adults, are becoming more common in children and adolescents. While genetic factors can play a role, lifestyle and dietary habits are key contributors to this rising trend. The good news is that by identifying and managing dietary risks, parents can take proactive steps to safeguard their children's kidney health. Proper hydration is arguably the most critical factor, but specific foods can also tip the balance toward or away from stone formation.

Dietary Culprits and Their Role in Stone Formation

High-Oxalate Foods

The most common type of kidney stone is the calcium oxalate stone, formed when calcium in the urine binds with oxalate. While oxalate is a natural compound found in many plant-based foods, excessive intake can increase the risk of stone formation in susceptible children. Fortunately, the interaction can be managed by pairing oxalate-rich foods with calcium sources, which allows the calcium and oxalate to bind in the intestines before they can reach the kidneys.

Here is a list of foods typically high in oxalate:

Spinach
Rhubarb
Nuts (especially almonds and cashews)
Chocolate and cocoa powder
Beets
Sweet potatoes
Wheat bran
Soy products
Certain berries, like raspberries and strawberries

Excessive Sodium (Salt)

A high-sodium diet is a well-established risk factor for calcium kidney stones in both adults and children. Sodium intake increases the amount of calcium that is excreted into the urine, which then increases the likelihood of calcium-based stones forming. Processed foods are a major source of hidden sodium in many children's diets.

Common high-sodium foods to limit include:

Processed meats (e.g., hot dogs, bacon, deli meats)
Canned soups and vegetables
Packaged and frozen meals
Fast food items
Salty snacks (e.g., chips, crackers, salted nuts)

Added Sugars and Sweetened Beverages

Research indicates a link between high added sugar consumption and an increased risk of kidney stones. Fructose, in particular, can increase urinary calcium excretion and decrease urine volume, creating an unfavorable environment for stone formation. Sugary drinks are a significant contributor to added sugar intake in children.

Drinks to limit include:

Sodas, especially dark colas
Sugar-sweetened fruit juices and drinks
Energy drinks
Sweetened iced tea

Excessive Animal Protein

While a child's growing body needs protein, an excessive intake of animal protein can make urine more acidic and increase urinary calcium. This creates an ideal environment for uric acid stones and also contributes to calcium-based stones. Good sources of protein are important for health, so the focus should be on moderating intake and balancing it with plant-based sources.

A Balanced Approach to Prevention

Prevention of kidney stones in children revolves around a balanced diet that is rich in water and low in stone-promoting substances. It's crucial not to restrict calcium, as this can be counterproductive; instead, the focus should be on managing sodium and oxalate intake.

Food Comparison for Kidney Stone Prevention


Foods to Limit or Avoid	Healthy Alternatives to Encourage
Sugary drinks (soda, sweetened juice)	Water, sugar-free lemonade or limeade
High-sodium processed foods	Fresh foods prepared at home with herbs and spices
Excessive red and organ meats	Plant-based proteins (beans, lentils, tofu, unsalted nuts)
High-oxalate items (e.g., spinach, rhubarb)	Balanced with calcium-rich foods like yogurt or cheese
High-dose Vitamin C supplements	Vitamin C from food sources like oranges and bell peppers

The Role of Adequate Hydration

Drinking enough fluids is the single most important lifestyle change for preventing all types of kidney stones. Proper hydration helps to dilute the urine, making it less likely that minerals and salts will concentrate and form crystals. Water is the best choice, but low-sugar citrus drinks can also be beneficial as they contain citrate, which helps prevent stones from forming.

A Final Word on Individual Needs

While these dietary guidelines offer a strong foundation, it's essential to consult a healthcare provider or a registered dietitian for personalized advice. The best diet can vary depending on the type of kidney stone a child is prone to, which is determined through a full medical evaluation. A professional can help create a tailored nutrition plan that supports healthy growth while minimizing stone risk. You can find more comprehensive information on the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) website.

Conclusion

Addressing the question of what foods cause kidney stones in children? involves looking beyond simple culprits. A balanced diet, vigilant hydration, and moderation of key food components—such as oxalates, sodium, and added sugars—are crucial. By making informed nutritional choices and seeking professional guidance, parents can significantly reduce their child's risk of kidney stones and promote long-term kidney health.

Frequently Asked Questions

No, drinking milk and getting enough dietary calcium from food sources is actually protective against calcium oxalate kidney stones, as calcium binds to oxalate in the gut before it can reach the kidneys.

Vegetables high in oxalate that may need moderation or pairing with calcium-rich foods include spinach, rhubarb, beets, and sweet potatoes.

Children do not need to avoid all salt, but excessive sodium intake should be limited, particularly from processed, canned, and fast foods. Using herbs and spices for flavor is a good alternative.

High doses of vitamin C from supplements may increase oxalate production and risk of stones. It is recommended that children get their vitamin C from food sources rather than high-dose supplements.

Nuts like almonds and cashews are high in oxalate. For children with calcium oxalate stones, these should be consumed in moderation and ideally paired with a calcium-rich food to minimize risk.

Water is the best fluid for prevention as it effectively dilutes urine. Low-sugar citrus drinks like lemonade can also help by providing citrate, which inhibits stone formation.

Processed foods are often high in sodium, which increases urinary calcium excretion. Some also contain added sugars and phosphorus additives that can contribute to stone formation.