I was changed from AdcalD3 (twice a day) to theiCalD3 (once a day) obviously because it was cheaper, but they are fine and chewable. Just tell your doctor you can't swallow the other ones and ask him/her to change your prescription.
My other half took it for about five years then at her medication review last year was taken off it. She’s not sure if the gp will want her to go back on it at some point but has decided not to anyway as she hated taking it and was a bit frightened by potential side effects.