Dr. Weil's unique and easy-to-swallow vitamin D. Q I understand that you are changing your vitamin D recommendation. why? A Yes, I am raising my recommendation for vitamin D to 1000 IU per day. Evidence has been accumulating to suggest that higher daily doses are necessary for optimum health in adults. We need vitamin D to facilitate calcium absorption and to promote bone health and this unique dot provides a full 1,000 IU in an easy-to-swallow tablet.