Many women struggle to breastfeed. Scientists are starting to ask why
I started aggressively filtering my water (Berkey black + white filters) during my last pregnancy, and I was amazed how much better I felt and how much more water I wanted to drink.  I was trying <i>very</i> <i>hard</i> to drink lots of water to support the pregnancy, and found it difficult.  When I started filtering it, it became really easy and I felt a lot better to boot.<p>I still get pretty low key dehydrated if I try to subsist on tap water.  I suspect my body is balancing my need for water against something in the water it doesn&#x27;t like.  Fluoride is a prime suspect, but any number of other things are possibilities and I wouldn&#x27;t really have any way to know.  But I do often wonder if I&#x27;m far from the only one with such an issue, and most people never find it. 
 I didn&#x27;t for a long time.  It is an easy guess for me that if there&#x27;s something in the water that&#x27;s bothering you, and you need to dramatically increase your intake to support two people, biological problems and tradeoffs might ensue.  And nursing in particular does require an awful lot of water.<p>I ultimately started filtering all of my water, and it seems like an obvious thing to do in retrospect -- like having a firewall for your home network.  It seems silly to me now that I ever assumed that any old pipe sludge that found its way into the system at any point was something I would necessarily want in my body.