This once-daily vitamin D2 supplement uses D2 derived from cultured yeast that is exposed to UV light, which triggers vitamin production much like the sun triggers it in human cells. Every batch of Amazon Elements vitamins and supplements is rigorously tested to ensure quality and safety. See our most recent test results for this product below. DETAILS: 65 capsules. 2 month supply (taken daily at the listed serving size). Made in a Good Manufacturing Practices facility.