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single report, the UL is set 20 percent below the level identified by Heaney et al. (i.e., 5,000 IU), specifically at 4,000 IU/day.

This value is greater than that set in 1997 by the previous IOM committee. A UL of 4,000 IU/day is still, however, a reference value that reflects the interest in providing public health protection, especially when existing data do not support benefit above such intakes. Intake values in the range of 4,000 IU/day would not appear to cause serum 25OHD levels to exceed 125 to 150 nmol/L,7 a concentration which is at the high end of the range of serum levels associated with nadir risk of outcomes such as all-cause mortality.

ULs for Children and Adolescents 1 Through 18 Years of Age

Children 1 Through 3 Years of Age


UL 2,500 IU (63 μg)/day Vitamin D

Children 4 Through 8 Years of Age


UL 3,000 IU (75 μg)/day Vitamin D

Children 9 Through 13 Years of Age

Adolescents 14 Through 18 Years of Age


UL 4,000 IU (100 μg)/day Vitamin D

No specific data are available for age groups other than adults and infants. In 1997 it was determined that increased rates of bone formation in toddlers, children, and adolescents suggested that the adult UL is appropriate for these age groups (IOM, 1997). The present committee chose to scale down the adult UL for younger children—to 2,500 IU/day for 1- to 3-year-olds and 3,000 IU/day for 4- to 8-year-olds—so as to be more consistent with concepts of graded tolerances with maturity. Although the simulated dose–response relationship between vitamin D intake and serum 25OHD level described in Chapter 5 is not affected by age, the data available did not include any children younger than 6 years old. There is no quantitative basis for such scaling, but it reflects a cautious and prudent approach given current biological understandings. Children and adolescents between 9 and 18 years of age have ULs that are the same as that for adults. All the UL values for children are slightly higher than the values provided in 1997 (IOM, 1997).


Use of the regression model developed to estimate the vitamin D intakes needed to achieve a specific level of 25OHD in serum is not appropriate for this situation, in that the model was derived using data based on minimal sun exposure and did not anticipate estimations of such high levels of intake. However, the use of the related equations suggests that 4,000 IU/day results in a mean serum 25OHD concentration of 91 nmol/L and an upper level of 105 nmol/L.

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