Bovine cartilage is typically recommended at 3 grams three times per day. Shark cartilage is sometimes taken in much higher amounts (e.g., 60 to 100 grams per day orally or by enema). These amounts are based on animal and anecdotal evidence and their safety and efficacy have not been confirmed by controlled clinical trials. Not only is toxicity information on this amount of shark cartilage lacking, but the amount of calcium in this amount of shark cartilage exceeds the 2 to 2.5 grams per day that is commonly considered to be the upper limit of safe intake. Type II collagen, when used for its effects on the immune system in rheumatoid arthritis, is used in very small amounts, from 0.02 mg to 10 mg per day. Gelatin and collagen hydrolysate is recommended at 7 to 10 grams per day.