Hello there.
I can understand your concern.
Rather than commenting on if the medicines are safe, be aware than its not SAFE to have such low
vitamin d3 levels.
Also, if medicines were not safe, they wouldn't be prescribed in the first place. Now its upon you to decide whether you want to take the medicines or not.
Get adequate sun exposure also. If you had been doing that, you wouldnt have had such low levels in the first place. It will take a long time, even more tha ln 12 weeks for your levels to improve.
Best regards.
Dr. Anil kumar jain.
Bangalore.