LBSAT230 Daily Variation In Serum Calcifediol In Japanese And Non-japanese Adults
Bibliographic record
Abstract
Abstract Circadian rhythm and 24-hour intra-subject variation in serum calcifediol (25-hydroxyvitamin D3) in the absence of vitamin D supplementation or treatment are poorly studied in healthy adults of any race. To address this dearth of information, a single-center, open-label study was completed in the US to evaluate both of these parameters in 67 male and female (balanced for gender) first generation Japanese (n=35) and non-Japanese (n=32) subjects, aged between 18 and 55 years. "First generation" was defined as: born in Japan; had 2 Japanese biological parents and 4 Japanese biological grandparents; had lived outside of Japan for less than 5 years; and, had made no significant changes in lifestyle, including diet, since leaving Japan. "Non-Japanese" was defined as: not of Japanese or Asian descent; and, parents and grandparents were not born in Japan or in any Asian countries. Enrolled subjects had a body mass index within 18. 0 to 30. 0 kg/m2 (inclusive) and body weight not less than 50 kg. The body weight for non-Japanese subjects was 9% to 17% higher than that of Japanese subjects (60.3 to 92.9 kg versus 51.2 to 84.9 kg). Exclusion criteria included consumption of a vitamin D supplement within the previous 28 days, consumption of grapefruit or oranges, alcohol, medications or tobacco within the previous 72 hours, and participation in strenuous physical activity within the previous 72 hours. Subjects were housed in a Phase 1 unit for 2 days where they received only standardized diets. Blood samples were collected on the second day at 0, 2, 4, 6, 8, 10, 12, 16 and 24 hours for determination of serum calcifediol by LC/MS/MS (mean accuracy: 0.37%; mean precision: 3. 07%) at Syneos Laboratories (Quebec, Canada). For all subjects, mean serum calcifediol levels ranged from 20.90 to 22.24 ng/mL over the 24-hour collection period with an average inter-subject variation (SD) of 6.79 ng/mL. A circadian rhythm was not evident either in the total population or in the racial subgroups. Mean intra-subject variation over 24 hours was 1. 08 ng/mL (SD; range: 0.27-3.22) or 5. 05% (CV; range: 2.36-14.81). Differences in 24-hour intra-subject variation between races were not significant (P>0. 05). These data support the conclusions that: (1) clinically meaningful circadian rhythms in serum calcifediol are absent in healthy first generation Japanese and non-Japanese adults living in the US; (2) the mean diurnal variation in serum calcifediol is small (approximately 5%); and (3) vitamin D therapies may appropriately be considered "physiological" if they raise serum total 25-hydroxyvitamin D after each dose only within the bounds of normal diurnal variation thereby allowing gradual adaptation to repletion. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".