Simon R.R.,Intertek |
Phillips K.M.,Virginia Polytechnic Institute and State University |
Horst R.L.,AMES Inc. |
Journal of Agricultural and Food Chemistry | Year: 2011
This study compared the compositional changes in mushrooms exposed to sunlight with those occurring after commercial ultraviolet (UV) light processing. Button mushrooms (75 kg) were processed in the presence or absence of UVB light; a third group was exposed to direct sunlight. Mushroom composition was evaluated using chemical analyses. Vitamin D concentrations were 5, 410, and 374 μg/100 g (dw) in control, UVB, and sunlight groups, respectively. On a dry weight basis, no significant changes in vitamin C, folate, vitamins B 6, vitamin B 5, riboflavin, niacin, amino acids, fatty acids, ergosterol, or agaritine were observed following UVB processing. Sunlight exposure resulted in a 26% loss of riboflavin, evidence of folate oxidation, and unexplained increases in ergosterol (9.5%). It was concluded that compositional effects of UVB light are limited to changes in vitamin D and show no detrimental changes relative to natural sunlight exposure and, therefore, provide important information relevant to the suitability and safety of UVB light technology for vitamin D enhanced mushrooms. © 2011 American Chemical Society. Source
Heaney R.P.,Creighton University |
Heaney R.P.,Btr Inc. |
Recker R.R.,Creighton University |
Grote J.,AMES Inc. |
And 2 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2011
Background: Current unitage for the calciferols suggests that equimolar quantities of vitamins D 2 (D2) and D 3 (D3) are biologically equivalent. Published studies yield mixed results. Objective: The aim of the study was to compare the potencies of D2 and D3. Design: The trial used a single-blind, randomized design in 33 healthy adults. Calciferols were dosed at 50,000 IU/wk for 12 wk. Principal outcome variables were area under the curve for incremental total 25-hydroxyvitamin D [25(OH)D] and change in calciferol content of sc fat. Results: Incremental mean (SD) 25(OH)D area under the curve at 12 wk was 1366 ng · d/ml (516) for the D2-treated group and 2136 (606) for the D3 (P < 0.001). Mean (SD) steady-state 25(OH)D increments showed similar differences: 24 ng/ml for D2 (10.3) and 45 ng/ml (16.2) for D3 (P < 0.001). Subcutaneous fat content of D2 rose by 50 μg/kg in the D2-treated group, and D3 content rose by 104 μg/kg in the D3-treated group. Total calciferol in fat rose by only 33 ng/kg in the D2-treated, whereas it rose by 104 μg/kg in the D3-treated group. Extrapolating to total body fat D3, storage amounted to just 17% of the administered dose. Conclusion: D3 is approximately 87% more potent in raising and maintaining serum 25(OH)D concentrations and produces 2- to 3-fold greater storage of vitamin D than does equimolar D2. For neither was there evidence of sequestration in fat, as had been postulated for doses in this range. Given its greater potency and lower cost, D3 should be the preferred treatment option when correcting vitamin D deficiency. Copyright © 2011 by The Endocrine Society. Source
Black W.C.,AMES Inc.
IEEE ISPLC 2010 - International Symposium on Power Line Communications and its Applications | Year: 2010
Distribution transformers are generally assumed to block high frequency power line carrier signals and to require bypass networks where signals must cross a transformer. In this work, however, we show experimentally that significant coupling occurs at some frequencies both across distribution transformers and between different transformer phases in various commercial transformers. This suggests that the transformers may pass noise and coupled RF signals between low and medium voltage power lines much more readily than predicted by simple models. It also suggests that frequency adaptive or spread-spectrum methods should be able to communicate across distribution transformers without bypass networks. Measured results are applied to a commercial simulator model suitable for use within large simulations. ©2010 IEEE. Source
Eliassen A.H.,Harvard University |
Spiegelman D.,Harvard University |
Hollis B.W.,Medical University of South Carolina |
Horst R.L.,AMES Inc. |
And 2 more authors.
Breast Cancer Research | Year: 2011
Introduction: Experimental evidence indicates vitamin D may play an important role in breast cancer etiology but epidemiologic evidence to date is inconsistent. Vitamin D comes from dietary intake and sun exposure and plasma levels of 25-hydroxyvitamin D (25(OH)D) are considered the best measure of vitamin D status.Methods: We conducted a prospective nested case-control study within the Nurses' Health Study II (NHSII). Plasma samples collected in 1996 to 1999 were assayed for 25(OH)D in 613 cases, diagnosed after blood collection and before 1 June 2007, and in 1,218 matched controls. Multivariate relative risks (RR) and 95% confidence intervals (CI) were calculated by conditional logistic regression, adjusting for several breast cancer risk factors.Results: No significant association was observed between plasma 25(OH)D levels and breast cancer risk (top vs. bottom quartile multivariate RR = 1.20, 95% CI (0.88 to 1.63), P-value, test for trend = 0.32). Results were similar when season-specific quartile cut points were used. Results did not change when restricted to women who were premenopausal at blood collection or premenopausal at diagnosis. Results were similar between estrogen receptor (ER)+/progesterone receptor (PR)+ and ER-/PR- tumors (P-value, test for heterogeneity = 0.51). The association did not vary by age at blood collection or season of blood collection, but did vary when stratified by body mass index (P-value, test for heterogeneity = 0.01).Conclusions: Circulating 25(OH)D levels were not significantly associated with breast cancer risk in this predominantly premenopausal population. © 2011 Eliassen et al.; licensee BioMed Central Ltd. Source
Horst R.L.,AMES Inc.
Journal of Steroid Biochemistry and Molecular Biology | Year: 2010
Demand for circulating 25-hydroxyvitamin D [25(OH)D] measurements has exploded due to its relationship with many serious health problems. The present study was designed to investigate the validity of samples " spiked" with 25-hydroxyvitamin D2 [25(OH)D2] or 25-hydroxyvitamin D3 [25(OH)D3] to determine their analytical recovery by the DiaSorin LIAISON 25 OH Vitamin D Total Assay (DiaSorin Assay) and high-performance liquid chromatography (HPLC). 25(OH)D was measured in nine volunteers taking large daily doses of vitamin D2 for 2 weeks. Samples were obtained pre-supplementation and 1 week following vitamin D2. Pre-supplementation samples were used for exogenous recovery studies by adding 25(OH)D2 or 25(OH)D3. Endogenous 25(OH)D [25(OH)D2 plus 25(OH)D3] concentrations reported by the DiaSorin Assay or detected by HPLC were in excellent agreement. However, exogenously added 25(OH)D2 and 25(OH)D3 were under-recovered by the DiaSorin Assay. NIST vitamin D standards containing serum from another species (horse) or exogenous 25(OH)D2 were similarly affected when using the DiaSorin Assay. Exogenous 25(OH)D2, 25(OH)D3 or serum from other species added to human samples is inappropriate in determining the analytical recovery of vitamin D compounds when using the DiaSorin Assay. Only endogenous 25(OH)D2 and/or 25(OH)D3 contained in human blood samples should be utilized for this purpose. © 2010 Elsevier Ltd. Source