We all know what nutrients are; they are substances that we obtain through our diets which help in proper growth and development of our body. Whereas, anti-nutrients as the name suggests are substances which inhibit the action of nutrients in our body. These are mainly present in plants or are said to be of plant origin and play a role in the plant’s life by protecting it against certain bacterial invagination. There are many anti-nutrients like oxalates, lectin, phytates, saponin, tannin etc. 

Oxalic acid (HOOC-COOH) is commonly found in both plants and animals. It is a strong organic acid. They are mainly found in green leafy vegetables, vegetables, fruits, cocoa, nuts and seeds. They are found mostly as oxalates that are formed by their combination with minerals. Oxalic acid and its salts occur as end products of metabolism in a number of plant tissues. It is also an end product of many mammalian metabolism. The term oxalic acid and oxalates are mostly used interchangeably in nutrition science. 

In the human body, after consumption oxalic acid is bound with minerals like calcium, magnesium etc to form oxalate. Oxalate is the salt of oxalic acid. The oxalates so formed have the capability of absorbing the minerals from the gut itself. This binding process leads to improper absorption and utilisation of minerals in the body though they are consumed adequately. Thus leading to deficiency disorders like osteomalacia and rickets. Excess formation of calcium oxalate can lead to conditions like kidney stones and formation of crystals in the various joints in the body.  

The loss caused by each anti-nutrient varies from one individual to another depending on their metabolic differences and also the various processes the food has undergone before consumption. Thus, it can be only advised to avoid consumption of food containing these nutrients in large quantities and to have an overall balanced meal throughout the day. Those who have or are at risk of having deficiency disorders due to minerals should monitor their meals and reduce consumption of food with anti-nutrients or to alter their pattern of consumption for example having tea before meal than along with the meal or may be taking calcium supplements only a few later after the meal if the meal contains oxalates. 

This doesn’t mean that one should consume a no oxalate diet as they are mostly found in foods which are rich in fibre and other nutrients.