Nitrate and nitrite content in daily hospital diets during the winter season--comparison of analytical and calculation methods.

A comparison of two methods: analytical and calculation on an estimation of dietary intakes of nitrate and nitrite from six different types of general hospital diets was studied. Studies were performed in the winter season of 1996-1997. It was found that the mean daily intake of nitrates was 85 mg per person in the analytical method, and 65 mg per person in the calculated method. The estimation of average dietary intakes of nitrite was adequate: 1.67 mg per person (the analytical method) and 1.18 mg per person (the calculated method). The main source of nitrates were vegetables, whereas the main source of nitrites was meat and meat-containing products. We suggest that the different methodologies, analytical and calculation methods, for measuring dietary intakes of nitrate and nitrite from diets make it possible to make direct comparisons of intakes.