How Much Vitamin D Should You Take? 4.83 (96.67%) 30 votes The safe dose of vitamin D supplementation to get most of the population to the optimal level is 2,000 IU a day, but the elderly and overweight may need more.
roadblock. 1  n any condition that makes it difficult to make progress or to achieve an objective. 2  n a barrier set up by police to stop traffic on a street or road in order to catch a fugitive or inspect traffic etc.
UNDERSTANDING BARRIERS TO LEARNING. A complex and dynamic relationship exists between the learner, the centre of learning, the broader education system and the social, political and economic context in which they are all part. complex and dynamic relationship exists between the learner, the centre of learning, the broader education system and the social, political and economic context in which they are all part.