Hi Lavanya ,
I have read your question,
Since you have said that you are diabetic and suffering from loose motion
, it could be slightly serious ,but don't worry since it is not incurable.
A diabetic patient is prone to infections easily, hence gastrointestinal problems could also be an issue .
Without Physical examination and medical history it would not be suitable to conclude anything here but yet I would like to suggest you to try oat meals for breakfast and evening snack, and trigonella fracens-grans(=methi) powder after having the meal ,Since these two Tackle diabetes
and loose motions effectively and try to take electolytes as much as possible.
For vitamin D the prescribed medicine is suitable.
Yet if you have any further issues i would such you to consult a general physician nearby.
Feel free to email me in any need of help anytime.
Wishing you get well soon ,