"The ubiquitous availability of supplements might indicate that even healthy children and adolescents profit by taking them," wrote lead author Wolfgang Sichert-Heller in the Journal of Nutrition (Vol. 136, pp. 1329-1333).
The results are part of the ongoing Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study, and are based on the three-day weighed dietary records of 931 German subjects between two and 18 years of age.
The researchers, from the Research Institute of Child Nutrition at the University of Bonn, found that eight per cent of male and 7.1 per cent of females regularly consumed dietary supplements, with the highest frequencies in the late-teens (15 to 18 years of age).
Intake of 10 of the 13 vitamins investigated (vitamins A, B6, B12, C, E and K, and thiamin, riboflavin, niacin and biotin) was already at levels at least 80 per cent of the RDA for all age groups before supplementation.
Indeed, vitamin A levels actually exceeded the tolerable upper levels (TUL) in 32 per cent of all the toddlers. Vitamin A is stored in the body and too much of the vitamin can lead eventually to liver problems.
"Intake of vitamin D, vitamin E, and vitamin C exceeded the tolerable upper limit in single age groups only, equal to less than seven per cent of subjects," said Sichert-Heller.
Folic acid levels also exceeded TUL in 13 per cent of the same age group.
Interestingly, other age groups were not getting enough folate/folic acid.
"In the case of folate and pantothenic acid, intake from supplements was necessary to achieve at least 80 per cent of recommended daily allowances for half of the age groups, especially in females," reported Sichert-Heller.
Despite vitamin D levels being exceeded in single age groups, the researchers found that other age groups failed to consume 80 per cent of their RDAs for the vitamin, despite supplementation.
Sichert-Heller concluded: "It is difficult to evaluate whether consumers receive more benefits or risks from the unrestricted consumption of supplements as they are marketed today."
According to Euromonitor, the German vitamins and dietary supplements market reached a value of €1,14m (U$1,410m)in 2004, a growth of five per cent from 2003.
Last year, US scientists reported that children in Iowa were regularly receiving supplements from their parents, and that at 24 months old 32 per cent of children were taking some form of dietary supplement despite obtaining adequate quantities of micronutrients from their diet.