There is mixed information about increasing your fluid intake and it’s correlation to increasing your milk supply. Bottom line- if you are dehydrated, you won’t produce enough milk. You’ll need to drink your bodies baseline fluids PLUS enough to create milk in order to keep things running at an optimum level.
The general recommendation is to drink half your body weight in ounces of water a day. So, if you weigh 150lbs, you would need to drink 75 ounces of water. In order to produce enough milk while keeping your body at a happy hydration level, it makes sense that you would need to add to this number by the amount of milk output you have. If you produce 30opd, then you would add 30oz to your 75oz base for a total daily intake of 105oz (just over 13 cups of water).
That’s a lot of water! My rule for fluid intake is:
Drink double what I pump in water each time with an 8 oz minimum. So, if I pump 2oz, I would drink 8oz. If I pump 5oz, I would drink 10oz and so on. In addition to this base water intake, I add other beverages as desired (decaf coffee, tea, hydration beverages, juice).
I fully believe that the biggest factors to my milk production success was this formula for water intake, increased calorie intake, and increased pump time.