A Brief Guide to Anti-Aging Supplements and Growth-Hormone-Releasing Nutrients for the Skin

Updated recommendations, developed in a collaboration between the United States and Canada, incorporate three types of values: the estimated average requirement (EAR), the recommended dietary allowance (RDA), and the tolerable upper intake level (UL). Collectively, these values are referred to as dietary reference intakes (DRIs). EAR is the intake value that is estimated to meet the requirements of a defined indicator of adequacy in 50% of the population (note that this means that the needs of 50% of the population are not being met). RDA is the dietary intake level that is sufficient to meet the nutrient requirements of nearly all individuals in the group. UL is not intended to be a recommended level of intake but represents the highest level of intake that is unlikely to have any adverse health effects in most individuals. It is important to note that the UL is not meant to apply to individuals receiving supplements under medical supervision and should not be used to limit doses investigated in clinical trials [42]. DRIs for antioxidant nutrients were developed by considering the roles of antioxidant nutrients in decreasing the risk of diseases, including chronic diseases and other conditions, and by interpreting the current data on intakes in the United States and Canada.