I have been taking mega flex tabs for the last 3 wks.I was doing regularly exercise , after doing scout exercise i had knee problem then it was very difficult for me while sitting down.Dr advise me to do blood test. Vit D3 level was 9.27, vit B12 - normal, uric acid normal.exercise stopped almost a month.I m doing physio exercise. At present, pain almost reduce, how long i have to take mega flex tabs?