FOOD SOURCES OF CALCIUM

Calcium absorption is regulated by a number of factors; its absorption can
be impeded by substances such as oxalates and phytates. Oxalates are
found in dark green leafy vegetables – especially spinach, as well as
rhubarb where the concentration is relatively high. Phytates are found in
whole grains, seeds, nuts and legumes; however, if these foods are
sprouted, soaked, leavened (think: sourdough bread), or gently heated
phytase (an enzyme naturally occurring in these foods) breaks down the
phytates and prevents their interaction with calcium absorption.