What is the difference between vitamin D25 hydroxy and vitamin D1-25hydroxy? Major...

I had my vitamin D level done at my Endocrinologist's office but this time she ordered 2 different tests.  She always just does the Vitamin D25 hydroxy but for some reason they can never get a reading when they process it in there office, so they have to send it out.  They think it is because my levels are too high.  So, this time she ordered 2 tests - vitamin D25hydroxy and vitamin D1-25 hydroxy.  Well, my D25 hydroxy was greater than 150 (up from 134) which totally freaked my Endo out but the Vitamin D1-25 was only 38.  I don't understand why there is just a big difference in the 2 tests? She had me stop my D for 1 and then I had to go back to get retested.  Turns out I couldn't go back for 10 days (went yestarday) and they will call me later this week with the results.  I can't go back on it until the results come back.  I normally take it 50,000 units of Dry D3, 3 times per week, so I guess that is too often.  I have been taking that dose for a year and all was fine but I guess with all my surgeries the past 5 months, everything got out of whack.  In December it had dropped to 50 because during the 2 months I was in the hospital, they weren't giving it to me (finally the last 2 weeks, I got someone to bring me mine and started taking it) and then in January it had increased to 134 - that was quite a jump.  Then March, greater then 150.  I think I definitely need to cut it to once or twice per week

PM Vitalady, she'd know