Dietary reference intakes (DRIs) are scientifically determined amounts of nutrients that are necessary for specific populations. For example, the DRI for calcium is different for people of different ages and greater for females than for males. There are established DRIs for bone-building nutrients (calcium, vitamin D, phosphorus, magnesium, and fluoride) and for the B-complex vitamins (thiamine, riboflavin, niacin, vitamin B6, vitamin B12, folate, biotin, pantothenic acid, and choline). The new guidelines account for physical activity as a factor affecting nutrient requirements. As scientific knowledge regarding nutrients increases, DRIs for other macro- and micronutrients will be published.
