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DRI Dietary Reference Intakes: For Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline
scientific considerations and judgments. The hallmark of the risk assessment model is the requirement to be explicit in all the evaluations and judgments made. Primarily as a result of database limitations, ULs are set for very broad age groups.
The UL values in Table S-2 for niacin, vitamin B6, folate, and choline were set to protect the most sensitive individuals in the general population (such as those light in weight).
The ULs for folate and niacin apply to forms obtained from supplements, fortified foods, or a combination of the two. As described in Chapter 8, the UL for folate is based on examination of case studies of progression of neurological effects in vitamin B12-deficient patients taking folate supplements.
Because of lack of suitable data, ULs could not be established for infants or for thiamin, riboflavin, vitamin B12, pantothenic acid, or biotin. This signifies a need for data. It does not signify that people can tolerate chronic intakes of these vitamins at levels exceeding the Recommended Dietary Allowance (RDA) or Adequate Intake
TABLE S-2 Tolerable Upper Intake Levels (ULsa), by Life Stage Group
a UL = maximum level of daily nutrient intake that is likely to pose no risk of adverse effects. Unless otherwise specified, the UL represents total intake from food, water, and supplements. Because of the lack of suitable data, ULs could not be established for thiamin, riboflavin, vitamin B12, pantothenic acid, or biotin. In the absence of ULs, extra caution may be warranted in consuming levels above recommended intakes.
b The ULs for niacin and folate apply to forms obtained from supplements, fortified foods, or a combination of the two.
c ND: Not determinable because of lack of data for adverse effects in this age group and concern with regard to lack of ability to handle excess amounts. Source of intake to prevent high levels of intake should be from formula and food only.