I don't think anyone has the certain answer to this question. Many nutritionists recommend 15 to 20 grams per day. Based on the results of this study, I have extrapolated a formula for calculating the daily need for collagen:
Ideal weight* x 0.14 : 0.25
The result indicates the daily grams to be taken
*Ideal weight: our weight without excess body fat. If you don't know your ideal weight there is a VERY homemade method to get an idea: subtract 10 from the inches of your height. Here is an example:
Height 1 meter 60 cm
Ideal weight 60-10 = 50 kg