Hello girls)) I would like to know if anyone had any side effects from…

Hello girls)) I would like to know if anyone had any side effects from baby drops (aqua-diet) in their babies? They prescribed one drop per day, and then started giving it and got constipation, worried, gas in the belly, stopped giving it and everything went away. Now I'm thinking what kind of D3 can I take now? What do you recommend? Thank you?