Vitamin D???

[Cydneybirdlova8]

Alright. So with this brutal winter, I have had to bring my hens and roosters inside and the only way my dad would let me keep them inside, was to keep them in my basement. So they aren't getting any vitamin d. Is it okay to give them vitamin d supplement? If so what would be the dosage? I have those golden large pills that you can pop open and squirt into their water. They have been inside for month and intend on keeping them for another month if not 2. Because we still have to fix the cage from the winds. So any feedback would be greatly appreciated!!!!