Hi. This tablet is generally safe. It won't have any side effects.
But please take it in the right dose (for your age,
Calcium should be 500mg twice a day).
Secondly, your knee won't improve with just this tablet. At your age, Osteoarthritis is the most common cause of pain in the knee.
If you do have Osteoarthritis, try the following:
*Hot water bag (10 minutes twice a day)
*After applying hot water bag, apply Nobel Gel
*Tab Flexon (1 tablet after lunch and 1 tablet after dinner for 7 days if you are not allergic to it)
*Tab Pantakind (40mg) (1 tablet before breakfast in the morning for 7 days)
*Follow the exercise given the video below:
https://m.youtube.com/watch?v=bE3xkOIekiU
*Avoid sitting/sleeping on the floor
*Avoid using stairs as much as possible
*Avoid using Indian Toilet.
Next Steps
Try the above steps and do let me know if you are feeling better after 1 week.