Diane May Nutrition Blog

What Are Oxalates?

September 4th, 2020

Oxalates are a naturally occurring compound found in many plants. This organic compound binds to calcium and blocks calciums absorption and is excreted in stool. Oxalates that are not bound to calcium travel as a waste product from the blood to the kidneys and are excreted in urine. Oxalates can also hinder nutrient absorption when eaten with fiber. Oxalate is produced as an end product of Vitamin C metabolism. Too much Vitamin C, usually through supplementation, can increase oxalate in your urine.Do not take more than 500 mg of Vitamin C in supplement form, especially if you are prone to kidney stones. The most common medical condition that would make it beneficial to reduce high oxalate rich foods is kidney stones. There are studies that have shown that high oxalate diets lead to joint pain, fibromyalgia, inflammation, autoimmune diseases and vulvodynia. These studies need further research. You do not need to remove all oxalates, as it would be virtually impossible! By combining calcium rich foods, you can reduce oxalate absorption. For conditions such as having calcium oxalate kidney stones, limit oxalate rich foods to no more than 100-50 mg per day. What else can you do to reduce oxalate stones?

  • Stay very well hydrated. 2L a day and bonus points if you put lemon in it as citric acid can reduce stone formation.
  • Stay at a healthy weight.
  • Do not over consume protein.
  • Consume no more than 2300 mg of sodium a day.
  • Avoid high fructose corn syrup and refined sugar.
  • Include calcium into your diet.
  • Avoid Vitamin C supplements.

A condition called hyperoxaluria occurs when you have too much oxalate in your urine. It can be caused by a genetic disorder, intestinal disease or eating too many oxalate rich foods. Oxalosis occurs after the kidneys fail for those who have primary and intestinal hyperoxaluria, and oxalates build up in the blood. This condition is rare. Primary symptoms include: severe and sudden back pain, pain below the ribs in the back that is persistent, blood in urine, pain when urinating and chills or fever. Always consult your doctor if you have pain and/or blood in your urine.

Foods high in oxalates include:

  • Spinach and dark leafy greens
  • Bran and bulgar
  • Rhubarb
  • Potato chips
  • French fries
  • Nuts and nut butters
  • Beets
  • Cocoa and chocolate
  • Sweet potato
  • Star fruit
  • Soy
  • Miso
  • Sesame seeds
  • Berries
  • Black tea
  • Cola
  • Coffee
  • Okra
  • Oranges

Some foods lower in oxalates:

  • Apples-peeled
  • Acorn Squash
  • Banana
  • Grapes
  • Nectarines
  • Papaya
  • Melons
  • Mango
  • Cabbage-white
  • Lettuce
  • Cucumbers
  • Peas-frozen
  • Summer squash
  • Mushrooms
  • Onions
  • Peppers-red
  • Corn
  • Carrots
  • Tomato
  • Dairy
  • Proteins
  • Lentils

It is important to note that most foods containing oxalates are good for you. Many oxalate foods are very healthy and nutritious. Removing them completely can lead to nutrient deficiency and poor health. Do not remove oxalates from your diet. Consume calcium and oxalate foods together to help bind the oxalates. When in doubt, talk to your doctor or RD.

A summertime favorite–zucchini casserole–gets an Italian spin in this delicious and healthy side dish with tomatoes, mozzarella and basil. You can use zucchini or summer squash in this caprese-style casserole, or a combination of the two. A sprinkling of fresh basil and a drizzle of balsamic vinegar just before serving brightens up the flavors. Serve with grilled or roasted chicken and some quinoa, rice or couscous to soak up the juices from the casserole for a satisfying and easy dinner. Source: EatingWell.com, June 2019



Ingredient Checklist


Instructions Checklist
  • Preheat oven to 400 degrees F. Coat an 8-by-8- or 7-by-10-inch baking dish with cooking spray.

  • Arrange squash and tomatoes decoratively, like rows of shingles (some may need to be cut in half), in the prepared dish.

  • Combine shallot, 1/4 cup basil, oil, salt and pepper in a small bowl. Spoon the mixture over the vegetables. Sprinkle evenly with mozzarella. Bake until the vegetables are tender and the cheese has melted, about 30 minutes. Sprinkle with the remaining 2 tablespoons basil. Drizzle with balsamic vinegar, if desired.

Nutrition Facts

87 calories; total fat 5.4g 8% DV; saturated fat 2g; cholesterol 9mg 3% DV; sodium 296mg 12% DV; potassium 326mg 9% DV; carbohydrates 5.7g 2% DV; fiber 1.2g 5% DV; sugar 3g; protein 4.8g 10% DV; exchange other carbs 1; vitamin a iu 809IU; vitamin c 18mg; folate 30mcg; calcium 121mg; iron 1mg; magnesium 23mg