Absorbability of Calcium From Common Beans

ABSTRACT Absorption of calcium from white, red, and pinto beans, labeled with 45Ca, was measured in 24 women in a three‐way randomized design using a calcium load of 72 mg and milk as the referent. Fractional absorption for the three beans averaged 0.219 ± 0.047 and did not differ by type. Milk calcium absorption at the same load was more than two times higher, 0.451 ± 0.088 (P < 0.001). Oxalate content averaged 0.34%, and phytate averaged 1.7%, a stoichiometric excess relative to calcium. To evaluate the relation of phytate to reduced absorbability, labeled pinto beans were pre‐treated with phytase and fed to 10 subjects. Fractional absorption rose, averaging 0.318 ± 0.071, (P