Association Between <i>LCT</i> ‐13910 C>T Genotype and Plasma 25‐Hydroxyvitamin D with Premenstrual Symptoms
Bibliographic record
Abstract
Background Vitamin D has been associated with premenstrual symptoms, but the findings have been inconclusive. Dairy is a good dietary source of vitamin D, but individuals with lactose intolerance consume less dairy and have lower plasma 25(OH)‐vitamin D levels. The LCT ‐ 13910 C>T gene variant is a strong predictor of lactose intolerance where those who have the CC genotype limit their intake of dairy. The objective of this study was to determine the association between 25(OH)‐vitamin D status and LCT genotype on premenstrual symptoms. Methods 964 women aged 20–29 years participating in the Toronto Nutrigenomics and Health Study provided data on their premenstrual symptoms and fasting blood samples were taken for genotyping and plasma 25(OH) D analysis. Optimal, sufficient, insufficient, and deficient vitamin D status was defined as ≥75, 50–74.9, 30–49.9, and <30 nmol/L, respectively. Logistic regressions were used to calculate the odds ratio (OR) and 95% confidence interval (CI) for the associations between vitamin D status and premenstrual symptoms. A Mendelian Randomization approach was used in the analysis of covariance to determine the association between LCT genotype and premenstrual symptoms. Results The odds ratio (95% CI) for experiencing clumsiness was 2.63 (1.32–5.21) for subjects with deficient plasma 25(OH)‐vitamin D status compared to those with optimal status. The corresponding odds ratios (95% CIs) for those experiencing confusion and with deficient or insufficient plasma 25(OH)‐vitamin D were 2.57 (1.42–4.67) and 1.82 (1.09–3.05), respectively, compared to those with optimal status. Plasma 25(OH)‐vitamin D status was not associated with experiencing any of the other premenstrual symptoms (acne, bloating, cramps, mood swings, increased appetite, fatigue, headache, anxiety, sexual desire insomnia, nausea, depression, or desire to be alone). The odds ratios (95% CIs) for experiencing clumsiness and cramps were 2.12 (1.08–4.17) and 0.55 (0.33–0.92), respectively, for individuals with the LCT CC genotype compared to those with the TT genotype. LCT genotype was not significantly associated with any of the other symptoms. Conclusion Our findings indicate that plasma 25‐Hydroxyvitamin D status and LCT genotype are associated with certain premenstrual symptoms, suggesting that dairy might be associated with both an increased and decreased risk of certain premenstrual symptoms. Support or Funding Information Research support: A.C.J. is a recipient of a Natural Sciences and Engineering Research Council Graduate Scholarship
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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) | 0.004 | 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".