My D was VERY low. I took prescription D 50,000 IU’s once a week. Once my numbers got into the bottom of the normal range I stopped taking it and switched to 1000 a day, and I put myself in the sun more than I have in the last 10 years. The last test I had a few weeks ago I was holding at the minimum for the normal range, so I am going to double to 2000 for the winter. I have several health problems, some are better lately, but I also increased my iron intake at the same time as the D, which could be part of it, and my thyroid has been a little more stable in the last 8 months compared to the last 5 years, so that helps me feel better also. So it is diffiuclt for me to say for sure the D helped directly or not. But, I do think there has to be something to the idea that women have so many health problems and we never let ourselves be in the sun anymore. I am very interested in vitamin K and how that affects the absorption of calcium into the bone (I did a question on that).