Very low Vit D

You can't get D3 in prescription strength levels.  You doctor has studied many years and does really know what they're talking about.  Take the D2 - you won't be sorry.

You can get D3 in 50,000 IU capsules without a prescription.  I would indeed be sorry if I developed osteopososis or heart disease due to vitamin D deficiency.  I respect your right to take D2 if you want.  I will take D3 and maintain my vitamin D level above 80, because I believe the research that shows that's what's optimal.

I don't take D2, I take D3.  I'm just saying you shouldn't tell someone that the D2 prescribed by their doctor was an error.  I think people too often worry about what is 'optimal'.  Test range normals were established for a reason.  Tweaking by buying expensive vitamins from different sites on the internet is not always necessary and, in some cases, it may not be wise.  Take what you want, but don't tell someone that their doctor is uneducated.  I think after spending nearly 13 years training, the doctor might take offense.  

I did not say the prescription was an error.  I said that D2 must be converted to D3 in the body, which is a scientific fact.  I did not say anyone's doctor was uneducated.  The OP asked why her doc prescribed D2 and I said I didn't know and suggested she ask the doctor why. I did say perhaps her doctor was unaware that D3 is absorbed better, but I didn't say the doctor was uneducated.  I have no idea what educated her doctor has received about nutrition.  Some medical schools offer NO courses in nutrition at all, but I don't know what school her doctor went to so perhaps he did receive some education in nutrition.

If you aren't concerned about having optimal vitamin levels, that's fine.  Since the OP posted the question, I assume she IS interested in having optimal vitamin levels, as am I.

Take what you want, but don't tell me that I shoudln't worry about having a good vitamin D level.

Most surgeons ARE uneducated when it comes to supplements/vitamins.  D2 does NOT work for anyone with WLS.  Why do they prescribe it, I don't know.  Think they know better and are not willing to listen and learn.  D3 is what we need and I will continue to tell people to not waste their money on vitamins that will not work for them or anyone else for that matter.  You talk about 'wasting' money on 'expensive supplements'.  I don't think $20 for 100 days worth of D3 is expensive.  You are giving out wrong info.  Stop it!

Unless you are a physician, I would suggest you stop spreading false information.  I've been prescribed D2 before and it has raised my levels just fine.  Having WLS does not make you a vitamin expert.  I suggest you take your own advice.

And a case study of 1 (you) does not make for statistical significance.  I will go by the overwhelming research, thank you very much and I'll advise anyone else to do the same.

Reading studies on the internet and interpreting them for yourself without proper medical training is dangerous.  I think many WLS patients are funneled into a program of buying unnecessary supplements.  Most of my nutrients come from my diet.  I had the D and iron deficiencies before surgery and they are about the same since.  Working with your doctor to find out exactly what your deficiencies are and how to rememdy those deficiencies is important, not reading articles written by people with specific interest in making money off those supplements.

You're the only one spreading false information.

D2 in large doses will up our levels somewhat for some people, but D3 at the same dose will always up levels higher and faster because it's more efficient and better absorbed. It's also cheaper.

You're missing the point entirely.  What I'm saying is that most Weight Loss Surgery patients' obsession with vitamin levels is absurd.  While it is important to have testing done on at least a yearly basis, and to be sure that our levels are in the normal range, vitamin fine-tuning is going to get you almost nowhere.  If your doctor prescribes D2, it will raise your levels.  Then you would be wise to take a D3 supplement.  That is what I do, and my levels are fine.  My annual blood work indicates I am very healthy and have minimal risk of heart disease.