1.Apart from aging, what are the causes , e.g. diet , habits or genes,of glucosamine deficiency? 2.To have maximum benefits to relieve knee pain, isn t it advisable to take glucosamine together with chondroitin and MSM instead of just glucosamine?What actually is MSM? 3.Why there is the warning to stop taking glucosamine after three months? What if I continue taking after the warned period?