Dietary reference intakes for vitamin D: justification for a review of the 1997 values.

Recent Institute of Medicine (IOM) reviews of the process for deriving Dietary Reference Intakes (DRIs) suggest that determining the need for a new nutrient review should be evaluated against criteria set a priori. After selecting the criterion of significant new and relevant research, a working group of US and Canadian government scientists used results from a systematic review and 2 conferences on vitamin D and health to evaluate whether significant new and relevant scientific evidence had become available since the 1997 IOM publication of the DRIs for vitamin D. This working group concluded that there appears to be new research meeting the criteria for 4 key DRI questions. The new research is of larger quantity and quality for the elderly than for other groups, but overall 1) adds to the bone-related and status evidence available to the 1997 DRI Committee for several of the life-stage groups, 2) identifies new outcomes with respect to risk of falls and performance measures in the elderly and potential adverse effects, and 3) provides additional information on dose-response relations between intakes and circulating 25-hydroxyvitamin D concentrations and between 25-hydroxyvitamin D concentrations and several health outcomes (ie, bone-related outcomes for all ages and risk of falls and performance measures in older adults). Members of the working group concluded that significant new and relevant research was available for reviewing the existing DRIs for vitamin D while leaving the decision of whether the new research will result in changes to the current DRIs to a future IOM-convened DRI committee.

Eating well with Canada's Food Guide (2007): development of the food intake pattern.

A food intake pattern specifying amounts and types of food was created for Canada's revised food guide, Eating Well with Canada's Food Guide (2007), using a two-step modeling process. In step one, food composites were manipulated to develop a food intake pattern. The second step used the step one food intake pattern to create 500 simulated diets for each of 16 age and gender groups. The resulting nutrient content distributions were evaluated relative to Dietary Reference Intake reference values. The modeling cycled between these two steps until a satisfactory pattern was achieved. The final pattern reflects modeling, a review of associations between foods and chronic disease, and input received during consultation.