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Oxalic Acid and Kidney Stones and Mineral Absorption

Two similar questions today regarding spinach.

Are you wondering  if eating spinach causes kidney stones?

Yes the oxalic acid in raw spinach is a factor to consider, but not a big factor for most people.

It would be best to eat most of your spinach sauteed in butter or lightly steamed. It is ok to eat raw spinach but maybe not a huge amount on a daily basis. I eat it both ways, maybe 3 or 4 days a week. There is not exact amount that can be prescribed for each person.

10-butterHaving butter on veggies allows for better mineral absorption.

Haas, MD says, “Foods that are high in oxalic acid – such as spinach, rhubarb, chard, and chocolate-can interfere with calcium, magnesium (and other minerals like iron) absorption by forming insoluble salts in the gut. Phytic acid, or phytates, found in whole grain foods may reduce the absorption of calcium and other minerals as well.”

Leafy greens like, kale, mustard and turnip greens have lower oxalic acid levels than spinach.

The point is, spinach and leafy greens are packed with nutrients that benefit the body.

  • 1 cup raw spinach has 2 mg iron, 15 calories, fiber, Vitamin A (4500IU /cup), folic acid, vitamin C, Potassium, magnesium, calcium, copper, manganese, zinc.
  • It is rich in phytonutrients (beta-carotene, lutein, zeaxanthin) which protect against damage to cell structure.
  • While it is true that the oxalic acid will bind some of the minerals we don’t need to throw the baby out with the bath water.
  • Go ahead and eat spinach, and mix it up between cooked and raw.

George Mateljan, author of The World’s Healthiest Foods, said, “In every peer reviewed research study I’ve seen, the ability of oxalates to lower calcium absorption definitely exists, but is relatively small, and definitely does not outweigh the ability of oxalate-containing foods. …  If you are concerned about oxalates, cooking spinach would actually be a way to reduce its oxalate content by 5 – 15%.”

If you want to eat raw spinach use baby spinach which has a lower oxalate content than mature spinach (Mateljan).

Mineral Absorption and Stomach Acid

If you are concerned about lower minerals, there are many factors that can reduce minerals like poor absorption. A big cause is low stomach acid and taking acid-lowering medication. According to Haas, calcium, iron and zinc are the minerals most commonly deficient in the diet.

Iron sources: vegetables have the poorly absorbed nonheme from of iron.

The best source of iron is the heme form from flesh foods, especially beef and liver but also fish, other meat, poultry (especially dark meat).

Eat both forms to increase your iron absorption.

Increase mineral absorption

  • Make sure stomach acids are high enough and stop taking Tums and acid-lowering drugs.
  • It may be necessary to supplement with Betaine HCl.
  • Eat animal flesh foods and cook in an iron skillet.
  • Do not drink pop and watch the coffee and black tea consumption.
  • Stop eating grains (phytates bind minerals).


Blausen_0595_KidneyStonesIf you are prone to kidney stones then you may want to follow a low-oxalate diet, but there are several other important factors to consider.


Many people are dehydrated and this contributes to kidney stone formation. Fluid intake is key – w.a.t.e.r. – drink about 3 quarts of water each day, or half your body weight in ounces of water.

Add fresh lemon juice to your water. The citric acid in fresh lemon juice has been shown to inhibit stone formation and break up small stones that are beginning to form. The recommendation from UW Hospital Metabolic Stone Clinic in Madison, WI is to add about 1/2 cup fresh lemon juice per day – this can be divided among several glasses of water. Always rinse your mouth after drinking lemon water, it can be hard on your teeth over time!

Sip on organic herbal teas like dandelion root tea which is a diuretic and promotes the elimination of waste products.

Watch Out: Protein, Fructose, Sugar, Processed Food

  • A high protein diet and a high intake of fructose will increase the amount of uric acid, a waste product that is formed and excreted by the kidneys.
  • An adult needs protein several times a day since the body does not store it, but limit your intake to moderate amounts of high quality protein from grass-fed, pasture raised animals and wild caught fish.
  • 3 – 4 ounces of meat is about right for a meal, less for a snack. Overall, the day’s protein intake may be around 60 – 100 grams per day.
  • A diet high in sugar, grains, soda and processed foods and processed salt will also promote the formation of stones.


  • When supplementing with Vitamin D, be sure to add Vitamin K2 to move the calcium from your your arteries into your bones. (Try Metagenics D3 5000 + K).
  • Harvard researchers found that increasing magnesium is very important in avoiding kidney stones. Add about 500mg of magnesium glycinate or magnesium citrate at bedtime. (Try Mg Plus Guard, Item #: MAG34).
  • Also Super B, B Complex.

K & B Tincture

K & B Tincture is formulated to nutritionally support normal kidney and bladder health.

Take 3 droppers of K & B in 4 oz water, or as directed on product label.

Ingredients: Juniper, parsley, Uva Ursi, Dandelion root, Royal Jelly with essential oils (Geranium, Fennel seed, Clove, Roman Chamomile, Sage, Juniper).

  • Juniper enhances the body’s efforts to maintain proper fluid balance.
  • Parsley supports kidney and bladder function and aids overall urinary health.
  • Uva ursi supports both urinary and digestive system health.
  • The therapeutic grade essential oils added to the ingredients fortify the effectiveness of its overall use for kidney and bladder support.

Essential Oils for Kidney Support

  • Grapefruit, lemon, geranium, juniper
  • Diffuse your choice of essential oils as desired.
  • Optional, put 2-3 drops of essential oil in your hands and rub them together, cup your hands over your nose, and inhale throughout the day.
  • You may apply essential oils topically. Mix 6 drops with a little coconut oil or other fatty carrier oil and rub on the back over the kidney area.

lemonade-225x252The kidneys remove waste products from the blood and help control blood pressure.

They filter over 200 quarts of blood each day and remove over 2 quarts of waste products and water that flow into the bladder as urine.

Remember that adequate pure water is vitally important, while drinking soda is one of the worst things you can do for fluid intake.


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