CALCIUM BIOAVAILABILITY FROM HIGH OXALATE VEGETABLES - CHINESE VEGETABLES, SWEET-POTATOES AND RHUBARB

Absorption of calcium from high calcium vegetables endogenously labell ed with Ca-45 was studied in premenopausal women using a randomized cr oss over design. Chinese (C.) vegetables are a major source of calcium , but the bioavailability is unknown and likely affected by the oxalic acid content. Calcium absorption from Chinese vegetables, sweet potat oes, and rhubarb, was compared to milk at the same calcium level for c alculation of an absorption index. Calcium absorption generally reflec ted oxalic acid content. Calcium absorption index (X +/- SEM) was leas t for C. spinach (0.257 +/- 0.0228) and rhubarb (0.235 +/- 0.0233), in termediate for sweet potatoes (0.423 +/- 0.0255), and highest for C. m ustard greens (1.097 +/- 0.0532) and C. cabbage flower leaves (1.097 /- 0.0532).