Living in Vermont, I don’t get much if any sun about ten months of the year. So I take Vitamin D3, in a small capsule. I took one 5K capsule a day, and it worked great. But now I’m taking two capsules a day, and it works even better. My daughter, who’s a nurse, takes 5 a day, on the recommendation of a crazy doctor she knows, and it seems to work well for her.