Bone Abstracts

Low levels of 25-hydroxyvitamin D have been documented among inhabitants of the wider Middle East and North African countries. Sunlight has long been recognized as a major provider of vitamin D. In this study we aimed to determine the optimum time for sun exposure in the Central region of Riyadh, Saudi Arabia. Ampoules containing 7-dehydrocholesterol in ethanol were exposed to sunlight every hour starting from sunrise until sunset in July and December. Our results demonstrated...