BELTSVILLE, MD. — Caffeine consumption among children may have declined from 2001-10, but on a given day 10% of those age 12-19 exceed the suggested Health Canada maximum caffeine intake level for their age group, according to a study that appeared on-line Aug. 27 in The American Journal of Clinical Nutrition.

Researchers from the Centers for Disease Control and Prevention and the U.S. Department of Agriculture’s Beltsville Human Nutrition Research Center analyzed caffeine intake of 3,280 children age 2-19 who participated in a 24-hour dietary recall as part of NHANES in 2009-10. Also, they examined trends from 2001-10 in 18,530 children age 2-19.

In 2009-10, 71% of U.S. children consumed caffeine on a given day. Median daily caffeine intake was 1.3 mg for children of the ages 2-5, 4.5 mg for the ages 6-11 and 13.6 mg for the ages 12-19. Non-Hispanic black children had lower caffeine intake than that of non-Hispanic white children. Daily caffeine intake from 2001-10 declined by 3.0 mg for children age 2-5 and by 4.6 mg for children age 6-11. No change was noted in children age 12-19.

Health Canada, Ottawa, recommends maximum caffeine intake levels of 45 mg per day for children 4-6, 62.5 mg per day for children 7-9 and 85 mg per day for children 10-12. Health Canada suggests daily caffeine intake of no more than 2.5 mg per kilogram (about 2.2 lbs) of body weight for children age 13 and older.

Both Health Canada and the U.S. Food and Drug Administration have said that for the average adult, daily caffeine intake of 400 mg is not associated with any adverse effects. The F.D.A. has not set a level for children.