Browsing by Author "Roseland, Janet Maxwell"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Interlaboratory Trial for Measurement of Vitamin D and 25-Hydroxyvitamin D [25(OH)D] in Foods and a Dietary Supplement Using Liquid Chromatography-Mass Spectrometry
    Roseland, Janet Maxwell; Patterson, Kristine Y.; Andrews, Karen W.; Phillips, Katherine M.; Phillips, Melissa M.; Pehrsson, Pamela R.; Dufresne, Guy L.; Jakobsen, Jette; Gusev, Pavel A.; Savarala, Sushma; Nguyen, Quynhanh V.; Makowski, Andrew J.; Scheuerell, Chad R.; Larouche, Guillaume P.; Wise, Stephen A.; Harnly, James M.; Williams, Juhi R.; Betz, Joseph M.; Taylor, Christine L. (2016-04-27)
    Assessment of total vitamin D intake from foods and dietary supplements (DSs) may be incomplete if 25-hydroxyvitamin D [25(OH)D] intake is not included. However, 25(OH)D data for such intake assessments are lacking, no food or DS reference materials (RMs) are available, and comparison of laboratory performance has been needed. The primary goal of this study was to evaluate whether vitamin D-3 and 25(OH)D-3 concentrations in food and DS materials could be measured with acceptable reproducibility. Five experienced laboratories from the United States and other countries participated, all using liquid chromatography tandem mass spectrometry but no common analytical protocol; however, various methods were used for determining vitamin D-3 in the DS. Five animal-based materials (including three commercially available RMs) and one DS were analyzed. Reproducibility results for the materials were acceptable. Thus, it is possible to obtain consistent results among experienced laboratories for vitamin D-3 and 25(OH)D-3, in foods and a DS.
  • Thumbnail Image
    Large Variability of Iodine Content in Retail Cow’s Milk in the U.S.
    Roseland, Janet Maxwell; Phillips, Katherine M.; Patterson, Kristine Y.; Pehrsson, Pamela R.; Bahadur, Rahul; Ershow, Abby G.; Somanchi, Meena (MDPI, 2020-04-28)
    Iodine intake is of contemporary public health interest. The recommended daily iodine intake is 150 µg for most adults, and milk is an important source of iodine in the U.S. diet. Iodine concentration in cow’s milk is affected by diet and iodine supplementation levels, milking sanitation practices, and other factors. Current analytical iodine data in U.S. retail milk are crucial for evaluating population-wide health outcomes related to diet. Samples of whole (3.25% fat), 2%, 1%, and skim (0–0.5% fat) milk were procured from 24 supermarkets across the U.S. using a census-based statistical plan. Iodine was analyzed by inductively coupled plasma mass spectrometry, including certified reference materials and control samples to validate results. No difference in iodine content was found between milkfat levels (F3,69 1.033, p = 0.4). Overall mean (SEM) was 85(5.5) µg/serving (240 mL). However, the 95% prediction interval of 39–185 µg/serving for individual samples indicated high variability among individual samples. Given the recommended 150 µg iodine per day for most adults along with the study mean, one milk serving can provide approximately 57% of daily intake. Researchers, health care professionals, and consumers should be aware of iodine variability in milk, while additional research is needed to investigate the impact of iodine variability factors.