Can taking 15 mg of folic acid decrease the absorbtion & effectivness of zinc, what happen if we take them separate like vit b9 morning & zinc evening?

may not be an issue: Good question. Some studies have shown that in those who had low zinc levels taking Folic Acid reduced zinc absorption ; utilization. Others have shown taking Folic Acid improves zinc absorption ; still others show no significant interaction! it does not seem to be an issue for most. You can try separating them but it may not be necessary. See http://lpi.Oregonstate.Edu/infocenter/minerals/zinc/.