Substances that alter the absorption of minerals
Some vegetables such as spinach, beet greens, parsley, celery and fruits such as strawberries and raspberries, including cocoa and tea have excellent nutritional properties of vitamins and antioxidants but also have a substance, oxalic acid and its salts, which precipitates of the calcium we take in the diet, thereby reducing its absorption by the body.
This entails no risk to human health, but should know and not to abuse these foods without compensating with higher intakes of foods that provide calcium as milk, yogurt or cheese.
Cereals, pulses and oilseeds have substances called phytic acid and phytase that hinder the absorption of calcium, copper, zinc, magnesium and iron by the intestinal mucosa.
Dietary fiber has the same effect.
Other vegetables in the cruciferous family such as mustard greens, turnips, radishes, cabbage, broccoli and oil seed rape, have substances called glucosinolates that are capable of generating isocyanates, which interfere with the metabolism of dietary iodine can cause goiter disease if they are abused and not compensated for by intake of other foods that provide iodine, like fish.
