My level was 17 last time I was checked, despite getting a daily IV dose...
50,000 IU of RX Vitamin D is D2. This must be converted by the body to D3, so it is not the best form to take.
I suspect an OTC Vit. D of 50,000 IU is also Vit D2...
There are different Vit. D tests. According to the Marshall Protocol, one should have both the OH 25 Vit D and the OH 1,25 Vit D levels checked. The 1,25 D is the activated form, and if this form is high, then supplementing may not be a good idea.
My personal opinion is this: My Husband was told by 2 Endocrinologists that the body uses 4-6000 IU of Vit D3 daily. It does not make sense to me to avoid supplementing Vit D3 if one does not go outside in the sunshine daily (those on Doxycycline, most of us in the mainland USA, etc.). The RDA of 400IU/day is pitifully low. There are a wide variety of ways to supplement Vit D3, and one easy way is to get an enteric coated Fish Oil supplement, then you get both Vit D3 and Omega 3 Essential Fatty Acids. Be sure to check the label for Vit D content. And always check with your LLMD/LLND before changing/adding supplements...