Comparison of a digital iodine-specific dietary screener with 24-hour recall and urinary iodine concentration.

Mild-to-moderate iodine deficiency remains a problem worldwide, including in Norway. Of particular, concern is fertile, pregnant and lactating women. The Norwegian Dairy Council developed a digital iodine-specific dietary screener (I-screener) for the assessment of iodine intake levels but has yet to be validated. The aim was thus to investigate the relative validity of the I-screener by comparing estimates of iodine intake from the I-screener against a single 24-hour recall (24HR) and urinary iodine concentration (UIC) in fertile women. Healthy females were recruited in Bergen in August-December 2021. Six spot-urine samples from six consecutive days were collected into a pooled sample to assess UIC. Each participant completed a single administration of the I-screener and the 24HR. The estimated daily iodine intake from the I-screener was compared with the estimations from the 24HR and UIC. Seventy-two women aged 19-39 completed the study. The median UIC was 76 µg/l. Compared with the 24HR, the I-screener placed 83 % of the participants in the same/adjacent tertial, with a slight agreement between the methods (Cohen's kappa = 0⋅187). The present study shows an acceptable correlation between the I-screener and the 24HR (r = 0⋅318), but not between the I-screener and UIC (r = 0⋅122). Despite its varying iodine estimate abilities, the I-screener may be used as an initial screening tool to rank fertile women on an individual level into deficient inadequate, and sufficient iodine intake. However, due to the relatively high risk of misclassification, further assessment of iodine status should follow.

Human Gastrointestinal Juices Intended for Use in In Vitro Digestion Models.

The aim of this study was to characterise the individual human gastric and duodenal juices to be used in in vitro model digestion and to examine the storage stability of the enzymes. Gastroduodenal juices were aspirated, and individual variations in enzymatic activities as well as total volumes, pH, bile acids, protein and bilirubin concentrations were recorded. Individual pepsin activity in the gastric juice varied by a factor of 10, while individual total proteolytic activity in the duodenal juice varied by a factor of 5. The duodenal amylase activity varied from 0 to 52.6 U/ml, and the bile acid concentration varied from 0.9 to 4.5 mM. Pooled gastric and duodenal juices from 18 volunteers were characterised according to pepsin activity (26.7 U/ml), total proteolytic activity (14.8 U/ml), lipase activity (951.0 U/ml), amylase activity (26.8 U/ml) and bile acids (4.5 mM). Stability of the main enzymes in two frozen batches of either gastric or duodenal juice was studied for 6 months. Pepsin activity decreased rapidly and adjusting the pH of gastric juice to 4 did not protect the pepsin from degradation. Lipase activity remained stable for 4 months, however decreased rapidly thereafter even after the addition of protease inhibitors. Glycerol only marginally stabilised the survival of the enzymatic activities. These results of compositional variations in the individual gastrointestinal juices and the effect of storage conditions on enzyme activities are useful for the design of in vitro models enabling human digestive juices to simulate physiological digestion.