Just wanted to mention, I've had great luck supplementing with D, and I really believe it's because of the kind I've been using. Not talking "gels V non-gels." I've heard of people on 50,000 IU injections and not getting the benefits of MegaFood's 2,000 IU twice daily. It's because brands like MegaFood use only elements/food that is recognizable by the human body and can be taken on an empty stomach (cause, hello, it IS food, haha). People are likely flushing out most of the D they take. I've heard New Chapter is a huge competitor of MegaFood, and Shaklee is also up there in the same helpful boat.
So if you give it another go, you might try researching the brands. Best of luck and clear skin to you...
It's true, sunlight's better because your body knows when to stop producing/converting D.
And I don't know what every brand does and how every company makes their product, but at the risk of sounding obvious, you could try googling it. You should always research products or medicine before using it.
This applies to all vitamin supplements. Your body will utilize them a thousand times better if they are whole food derived vitamins. New Chapter Organics, Vitamin Code Raw Vitamins, and a whole slew of others offer these. They are three times more expensive than your typical multi, but it's worth it if you use supplements.