Dietary intakes of some essential and non‐essential trace elements, nitrate, nitrite and N‐nitrosamines, by Dutch adults: Estimated via a 24‐hour duplicate portion study

Abstract

Duplicate portions of 24‐hour diets of 110 adults have been analyzed for aluminium, cadmium, copper, lead, manganese, mercury, zinc, nitrate, nitrite and volatile N‐nitrosamines. The mean daily intake of copper (1.2 mg) is only about 50% of recommended values; mean daily intakes for manganese (3.3 mg) and zinc (8.4 mg) are adequate and marginal respectively with respect to recommended amounts. For the non‐essential elements Al, Cd, Hg and Pb, mean daily intakes of 3.1 mg, 0.01 mg, 0.002 mg and 0.034 mg were found, respectively. For Cd this amounts to 17% of the acceptable daily amount, for Al, Hg and Pb 5%, 5% and 8%, respectively. Since 1976–1978 the dietary intake of lead has been reduced by a factor three; for the other six elements daily dietary intakes are almost the same as in 1976–1978. Average nitrate intake was 52 mg NO⁻ ₃/day, about 25% of the ADI. Only 16 diets contained a measurable amount of nitrite. The highest daily intake (0.7 mg NO⁻ ₂) is less than 10% of the ADI. Volatile N‐nitrosamines were detectable in two duplicate diets (NDMA and NPIP). It is estimated that the daily dietary intake of volatile N‐nitrosamines is around 0.1 μg or less.

Keywords:

• Daily intakes
• duplicate portion technique
• heavy metals
• nitrate
• nitrite
• nitrosamines

Notes

Present address: Netherlands Institute for Dairy Research (NIZO), P.O. Box 20, 6710 BA EDE, The Netherlands.