Bioavailability of enteric-coated microencapsulated calcium during pregnancy: a randomized crossover trial in Bangladesh (804.4)

Prenatal calcium (Ca) and iron (Fe) supplements are recommended in settings of low dietary Ca intake and high prevalence of anemia. However, concurrent Ca and Fe administration may inhibit Fe absorption. Therefore, we developed a multi-micronutrient powder containing Fe (60 mg), folic acid (400 µg), and Ca (0.5, 1.0 or 1.5 g) in which calcium carbonate granules were microencapsulated with a pH-sensitive enteric coating to delay intestinal release and limit Ca-Fe interactions. To compare the fractional intestinal absorption (fAb) of Ca from enteric-coated (EC) Ca granules versus uncoated (non-EC) granules, we conducted a randomized crossover trial among pregnant women (n=49) in Dhaka. fAb was estimated by a dual stable isotope method (44Ca-labeled granules and intravenous 42Ca), based on the relative recovery of 44Ca vs 42Ca in urine over 48 hours. Mean (±SD) fAb from EC Ca was significantly less than from non-EC Ca (2.7±2.2 % vs. 16.5±10.0 %; p<0.0001) at all 3 Ca doses. In conclusion, the pH-sensitive en...