DIETARY LENTILS AND CALCIUM BALANCE IN ADULT MEN

The effect of dietary lentils on calcium balance was evaluated in nine healthy male subjects. The Control and Experimental (+ 130 g dry lent ils) diets were each fed for three weeks in a cross-over design. Study diets were matched to subjects' usual calcium and energy intakes, and balanced for protein and phytate. Complete fecal collections were mad e for all weeks and 24-hour urine collections were made in Week 3 of e ach period. Calcium balance was maintained during both the Control (0. 4 +/- 0.8 mmol/day, mean +/- SEM) and Experimental periods (- 0.6 +/- 0.9 mmol/day); fecal calcium remained unchanged (28.5 +/- 1.7 mmol/day , 29.7 +/- 1.5 mmol/day, respectively). Urinary excretion, however, va ried from Control to Experimental periods for the following: calcium d ecreased from 5.43 +/- 0.44 to 4.53 +/- 0.41 mmol/day (P < 0.0001); so dium (Na) decreased from 149 +/- 4 to 133 +/- 3 mmol/day (P = 0.0003); potassium (K) increased from 90.8 +/- 4.7 to 102.5 +/- 3.1 mmol/day ( P = 0.015), respectively. Changes in urinary K and Na reflected dietar y intake levels. There was no change in net acid excretion. The decrea se in renal calcium excretion may be due to a protective role of dieta ry K as well as a decrease in renal Na excretion, independent of chang es in endogenous acid. This study shows that adding lentils to the die t, while maintaining a constant phytate intake, does not adversely aff ect calcium balance.