Excerpt

The charge to the committee (Institute of Medicine Committee to Review Dietary Reference Intakes for Vitamin D and Calcium) was to assess current relevant data and update, as appropriate, the DRIs (Dietary Reference Intakes) for vitamin D and calcium. The review was to include consideration of chronic disease indicators (e.g., reduction in risk of cancer) and other (non-chronic disease) indicators and health outcomes. The definitions of these terms are discussed below. Consistent with the framework for DRI development, the indicators to assess adequacy and excess intake were to be selected based on the strength and quality of the evidence and their demonstrated public health significance, taking into consideration sources of uncertainty in the evidence. Further, the committee deliberations were to incorporate, as appropriate, systematic evidence-based reviews of the literature.

Specifically, in carrying out its work, the committee was to:

• Review evidence on indicators to assess adequacy and indicators to assess excess intake relevant to the general North American population, including groups whose needs for or sensitivity to the nutrient may be affected by particular conditions that are widespread in the population such as obesity or age-related chronic diseases. Special groups under medical care whose needs or sensitivities are affected by rare genetic disorders or diseases and their treatments were to be excluded;

• Consider systematic evidence-based reviews, including those made available by the sponsors as well as others, and carefully document the approach used by the committee to carry out any of its own literature reviews;

• Regarding selection of indicators upon which to base DRI values for adequate intake, give priority to selecting indicators relevant to the various age, gender, and life stage groups that will allow for the determination of an Estimated Average Requirement (EAR);

• Regarding selection of indicators upon which to base DRI values for upper levels of intake, give priority to examining whether a critical adverse effect can be selected that will allow for the determination of a so-called benchmark intake;

• Update DRI values, as appropriate, using a risk assessment approach that includes (1) identification of potential indicators to assess adequacy and excess intake, (2) selection of the indicators of adequacy and excess intake, (3) intake-response assessment, (4) dietary intake assessment, and (5) risk characterization.

• Identify research gaps to address the uncertainties identified in the process of deriving the reference values and evaluating their public health implications.