Hi mama! I haven't personally tried NekoCee, but a few of my mum friends took various vitamins while breastfeeding and they were okay, though honestly, it's really best to check with your OB first before starting any supplement, kasi bawat mommy at baby ay different. What I know is maraming safe vitamins out there specifically formulated for breastfeeding moms, so your doctor can recommend what's best for you and baby.