Can Vitamin D deficiency cause thin/no shell in chickens?

[BetterHensandGardens]

This is my second winter with hens, yet this is the first winter we've had a problem with thin or non-existent shells. The hens get 3.5% calcium in their layer ration, and we offer oyster shell at all times, yet we're still having the problem. The 3 hens that are in their second year are having the problem, whereas a brand new hen (just started laying) does not seem to have the problem. We've had lots of snow so they've been indoors alot (almost all the time), could a lack of sunshine be causing Vitamin D deficiency and then the hens can't absorb the calcium?

 

[OrpingtonManor]

We've been wondering the same thing.
https://www.backyardchickens.com/forum/viewtopic.php?id=302770&p=1
I've started adding vitamins and electrolytes to the water, and that will increase their D3 intake. I'm hoping it helps.

 

[briteday]

I am having the same problem with my RIR hens that have just finished their second winter. I have one that lays a shell-less egg almost every week. Due to our location and run set up my hens get maximum sunlight and I even give them ~expired milk almost weekly, sometimes yogurt too. They are on Layena and I have no problems with my younger pullets and hens. I have to think it's about aging. I also had a very poor hatch from their eggs...fertile, developed, no hatch...less than 50% hatch. So I'm thinking that commercial growers have it down to a science when they choose not to keep hens beyond 18 months or so. They just aren't as productive, eggs or fertility.

 

[gritsar]

Yes it can, particularly vitamin D3:

http://www.thepoultrysite.com/publi...ndbook/16/thinshelled-eggs-and-shellless-eggs

 

[chookchick]

What about your water? Apparently some kinds of water (lots of heavy metals if I remember right), can cause them to have thin shells even if their calcium intake is adequate. There was a thread on this a while back, maybe I can find it when I'm not so tired...I doubt it is the lack of sunshine--we have so little sunshine around here, and my coop is in the shade, so my hens would be in big trouble if that was the case.