I don't have the knowledge to answer this question, but I can tell you I don't drink the first morning urine.I had read pregnant women should not drink their first urine, I assume it had to do with hormones and since I had a thickened endometrium I decided after I get up I drink a lot of water and take it midmorning.
I also prefer to test it to make sure it is not too acid.
This is off topic but I just happened to read about diabetes 1 the other day and you might be interested to read this, it has to with iodine