If 1500mg is taken a day it causes 375-450mg of salt to the diet per day. Other sources of glucosamine is shark cartilage and chondroitin sulfate, though are larger molecules. Many people die or are hospitalised due to painkillers and conventional medicines used for arthritis. People especially those allergic to conventional treatment may benefit from alternative treatments, though anybody who would like to try safe alternatives can try this. A natural source of glucosamine, chondroitin sulphate , hyaurolic acid is NZ greenshell mussel.
Some products also have extra glucosamine added and comes in forms for both animal and humans.
See petshop for animal use and below links for human products. Natural sources often have synergistic properties often undefinable which makes them effective or more absorbable. Eicosatetraenoic acid also in mussel may add to its effectiveness. Look at sports or rheumatism section for a range of products from different companies. None of the information is to be construed as medical advice.