I usually give human Caltrate a try. It has all the necessary minerals that work with Calcium so the hen can absorb and use it in the body. 1/2 of a Caltrate pill once a day. I break a pill in half, and then break this half into small pieces and stuff them into raisins. The bird doesn't know they are being medicated. This Calcium should start to take effect within a couple of days. Continue using it until you start to see a LOT of calcium bumps on the egg shell, you can back down to a couple of times a week. Sometimes if you remedy the situation of why she is laying thin shelled eggs, you can do away with it completely. Without the necessary minerals added to Calcium, it becomes very hard to absorb and use in the body.
If the Caltrate doesn't work, there are other reasons a bird lays thin shelled eggs....she is being bullied away from the feeders or waterers and is not getting enough to eat or drink.... she is being bullied while laying or is worried about being bullied in the nest box...over heating in the summer will cause thin shelled eggs...predators lurking at night causes enough stress they can't put a shell on...she has a defective shell gland...she is internally laying or has some sort of Reproductive Cancer...she has some other sort of illness that is causing her to be unable to put a shell on, and it is possible an over load of worms will do this too.
Try the Caltrate and see if it doesn't make a difference.
