Originally Posted by mrsD

That is D2.... there is only one RX form of D and it is the old plant derived form.

New evidence shows that it does not work well. Up to 87% less well than the OTC active form called D3.

Get your newest results, drop the RX D2, and use instead D3
(many places sell it--NOW brand and Puritan's are very inexpensive)
1000IU for every 10 pts you need to raise. If you are overweight, the fat on your body will take up some of it as well, so you might need to increase that 1000/10 to 1500/10pts or more. It takes about 3 months to show any changes with D supplements. So it is not a quick result.

D2 is not active in humans. It is very old, and back then no one knew that.

D3 is the active form, just like you get from the sun.