tors, but also indicated that the scientific judgment involved should be described. In developing ULs for calcium and vitamin D, the limited nature of the data resulted in the committee using UFs to adjust for uncertainties in the data. These were necessarily qualitative adjustments rather than quantitative adjustments. As suggested repeatedly during the 2007 workshop on DRIs (IOM, 2008), an educated guess for a reference value is more useful to stakeholders than the failure to set a reference value in the face of uncertainty.

Discussions related to calcium ULs are provided first, and then vitamin D ULs are considered. At the start, the committee identified potential indicators to assess adverse effects for excess intakes of calcium and vitamin D based on the available literature, as described below. The potential indicators considered are presented in Box 6-1.

Excess calcium intake from foods alone is difficult if not impossible to achieve. Rather, excess intakes are more likely to be associated with the use of calcium supplements. However, the potential indicators for the adverse outcomes of excessive calcium intake are not characterized by a robust