Evaluation of spot urine samples collected in the early morning for the study of solt-intake in children and mothers

A dietary survey and spot urine samples (about 10ml each), collected in the early morning on the three different days, were used to evaluate the daily salt-intake of 176 children (aged 3-6 years) and their mothers. The Na, K and Cr in each urine samole were mesured, The amount of salt (Nacl) excreted into urine each day was estimated by comparing Na and Cr levels with standart levels bases on height and body weight. According to the survey questionaire, the daily salt-intake in children was 4.8±0.9g and 10.6±2.0g in mothers. The urinary salt-excretion of children was 3.9±1.1g/day, significantly higher with age, and the level per kg (body weight) was almost fixed. It was 8.6±3.3g/day in mothers. The ratio of Na to K and the level of salt-excretion had a direct correlation with the daily diet. The spot urine samples were useful in our study of salt-intake.