Oxalate

Foods mg oxalate/100g
Rhubarb
 
Spinach
 
Soy burger patty
 
Beetroot
 
Almond
 
Tofu
 
Pecans
 
Peanuts
 
Okra
 
Chocolate
 
Collard greens
 
Sweet Potato
 
 600-1235
 
600-970
 
870
 
500
 
383
 
140-280
 
202
 
187
 
146
 
117
 
74
 
56
 
Other high oxalate foods: refried beans, swiss chard, dried figs, star fruit, almonds, sesame seeds and Tahini, Buckwheat, grits, most soy products.

Calcium oxalate crystals are formed in urine. The relative solubility increases much more with an increase in the oxalate concentration than with an increase in the calcium concentration. Thus, increased oxalate is likely to cause crystal formation in the urine, and eventually kidney stones. Not all studies of patients with kidney stones have been able to find an increase in urine oxalate or oxalate intake, but the urine oxalate will fluxuate from day to day, and some studies were not done at the time the stone developed.

Increased urine oxalate seen with:

  • Increased intake of oxalate-rich foods
  • Inflammation of lower intestine - this increases permeability and enhances oxalate absorption
  • Low calcium concentration in the lower intestine - calcium will bind to oxalate in the GI tract and thus prevent it from being absorbed.
  • Fatty acid malabsorption - the calcium will bind to the fatty acid so less is available to bind to the oxalate.
  • High doses of vitamin C, which is metabolized to oxalate.
  • Lack of intestinal bacteria which can metabolize oxalate.
  • Inborn errors of metabolism causing oxalosis.

    References

    Oxalosis Foundation has a comprehensive list of foods containing oxalate and lots of information.


    Updated 9/1/06