Works great, felt improvement in weeks. I like that it is 1000, makes it flexible in how I stack with other supplements that may have D in them, so I can achieve a good, safe daily dose. Remember to stack with K, they need each other to work. Good price and you can’t beat Thorne for quality. Wil continue to buy as long as I need D (so I’m pretty sure this will be a long-term possibly lifelong brand for me).