Be careful with this particular brand of Vitamin D. There are reports that they actually don't have any Vitamin D in them at all. See: [...]From the blog:She starting 25-hydroxy vitamin D blood level was 18.1 ng/ml. Severe deficiency, no surprise.On her 10,000 units per day, Vitamin Shoppe brand, her 25-hydroxy vitamin D level was 76.2 ng/ml--perfect. It stayed in this range for about two years.She then changed to the Nature Made brand gelcaps she picked up at Walgreen's. Repeat 25-hydroxy vitamin D level: 23 ng/ml.This has now happened with five different people, all taking the Nature Made brand.