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DRI Dietary Reference Intakes: For Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline
TABLE 9-10 Contribution of Fortified Foods to the Vitamin B12 Intake of U.S. Men and Women by Age Group, CSFII, 1995a
Contribution of Food Group to Total B12 Intakeb (%)
Adults ≥ 19 Years
Ages 51–70 Years
Ages 70+ Years
Soy-based supplements and meal replacements
Milk-based supplements and meal replacements
a CSFII = Continuing Survey of Food Intake by Individuals.
b Refers to the percentage contribution to the American diet for both men and women, based on 2-day weighted 1995 CSFII data.
SOURCE: Unpublished data from the Food Surveys Research Group, Agricultural Research Service, U.S. Department of Agriculture, 1997.
Intake by the elderly continues to be high relative to the EAR and RDA (Appendix F); however, quantitative data are not available on the amount of B12 provided by fortified foods. In a study of Boston elderly aged 60 to more than 90 years (Russell, 1992), median B12 intake by males who were not taking supplements was 3.4 µg/day. The median plasma B12 concentration for this unsupplemented group was 286 pmol/L (388 pg/mL). For females not taking supplements, the median B12 intake was 2.6 µg/day and the median plasma B12 concentration was 272 pmol/L (369 pg/mL). B12 intake was correlated with serum levels, but the actual correspondence of intake with plasma values was not determined.
Quinn and Basu (1996) reported on the dietary B12 intake estimated from 3-day (nonconsecutive) food records of 156 elderly males and females aged 65 to 77 years residing in Northern Alberta, Canada. Supplement users were excluded from the sample. The mean daily B12 intake by males was 3.7 ± 0.3 (standard error of the mean) µg and by females was 4.3 ± 1.0 µg. Mean plasma B12 was 286 ± 24 pmol/L (388 ± 33 pg/mL) for males and 335 ± 37 pmol/L (454 ± 50 pg/mL) for females, which is consistent with the difference in reported dietary intake. None of the males and 7 percent of the females had estimated intakes of less than 1.3 µg/day.