Grains bran, nuts, soy, spinach, rhubarb, swisschard, chocolate, black tea, some fruits and vegetables. Metabolite of fungus and dysbiotic flora. Metabolism of the amino acids glycine and serine, vitamin C and sugar.
Partially by cooking.
Binding with calcium: Calcium and magnesium deficiency, kidney stones, disturb digestive enzymes. Hyperoxaluria may play a significant role in autism, COPD/asthma, thyroid disease, fibromyalgia, interstitial cystitis, vulvodynia, depression, arthritis. Researchers believed that "Oxalate hyperabsorptionmay be the main reason for stone formation in more than half of the idiopathic calcium oxalate stone formers".
Oxalates affects calcium and magnesium metabolism and react with proteins to form complexes which have an inhibitory effect in peptic digestion. Ruminants, however unlike monogastric animals can ingest considerable amounts of high-oxalate plants without adverse effects, due principally to microbial decomposition in the rumen (Oke, 1969). The hulls of sesame seeds contain oxalates and it is essential that meals should be completely decorticated in order to avoid toxicities (McDonald et al., 1995). Chemical analysis carried by Alabi et al. (2005) on locust bean seeds revealed that the testa of locust bean seeds had the highest concentration of oxalate (4.96 mg/100 g) followed by the pulp (3.40 mg/100 g) and the cotyledon (1.15 mg/100 g). Olomu (1995) reported that pigeon pea contains about 0.38% oxalic acid. Oxalic acid binds calcium and forms calcium oxalate which is insoluble. Calcium oxalate adversely affects the absorption and utilization of calcium in the animal body (Olomu, 1995).