We know that soy product contain pythic acid. is it really safe to take isolated soy protein (amway, shaklee, ..) while breastfeeding?"

Let me help: Soy as a part of the regular diet is traditionally considered to be safe during pregnancy and breastfeeding, although scientific research is limited in these areas. The effects of high doses of soy or soy isoflavones in humans are not clear, and therefore are not recommended.

Phytic r folic acid?: Folic acid is strongly recommended before and during pregnancy to prevent neural defects like spina bifida. Phytic acid should probably be avoided during pregnancy & breastfeeding as it can chelate (bind to) important minerals like iron, calcium, magnesium, zinc & make them unabsorbable, leading to potential mineral deficiencies. Ask OB about this chemical.