Soy foods are a good source of calcium in comparison to the commonly used legumes. Processing affects the calcium content of soyfoods considerably. Tofu due to its processing methods can contain between 120 and 750 mg of calcium per 1/2 cup serving. Soymilk contains around 93 mg of calcium per one cup serving. The calcium-fortified soymilk could often contain between 200 and 300 mg of calcium per serving and a good amount of vitamin D. Although soyfoods are high in both oxalates and phytates that inhibit calcium absorption, the calcium from soyfoods is well absorbed and has an absorption rate equal to that of milk.
Soya is rich in iron too. However, both phytate and soy protein reduce iron absorption which leads to the iron in soyfoods being poorly absorbed. Iron could be better absorbed from fermented soyfoods like tempeh and miso.
A serving of soyabeans provides approximately eight grams of dietary fiber. However, some soy foods are processed in ways that decrease the fiber content significantly. Tofu and soymilk contain very little fiber, while soy foods that utilize the whole bean such as tempeh, soy flour and textured soy protein are high in fiber.
Like other whole grains, soyfoods are rich in B-vitamins, particularly niacin, pyridoxine and folacin. Soymilk is well fortified with vitamin B12 which makes it a prominent source of this essential nutrient