The Influence of Hormonal Contraception on Vitamin D Supplementation on Serum 25(OH)D3 Status in Premenopausal Women: A Prospective Double-Blind Placebo Random Controlled Trial
Bibliographic record
Abstract
Background: A number of cross-sectional studies have highlighted a potential benefit of estrogen-containing contraception on serum 25-hydroxyvitamin D (25(OH)D) levels. The purpose of the present prospective study was to determine whether oral vitamin D 3 supplementation significantly increases serum 25(OH)D more for women taking the estrogen-containing oral contraception than those not taking this medication. Methods: Thirty-eight premenopausal adult females aged 18 - 45 years old were recruited from a university campus; exclusion criteria included those presently taking vitamin D supplementation, those who stopped or started taking oral contraception in last 6 months and those taking any other form of contraception. A prospective double-blind placebo design was implemented; the dependent variable was serum 25(OH)D and the independent variables were using or not using oral estrogen-containing contraception, and vitamin D 3 or placebo supplementation. Participants were tested 4 weeks apart, and blood samples were collected using a capillary blood spot sample method and analyzed by liquid chromatography-tandem mass spectrometry. An independent technician prepared the identical supplement bottles with either 100 placebo pills or 100 active vitamin D 3 pills (1,000 IU per pill) and participants randomly selected a supplement bottle. Results: Baseline measurements of 25(OH)D were non-significantly 11% higher in those taking estrogen. ANOVA results revealed a significant two-way interaction between supplementation group (treatment vs. placebo) and treatment period (before vs. after) (P < 0.001), demonstrating a substantial rise in serum 25(OH)D for the treatment group compared with the placebo group. The results also identified a three-way interaction (P = 0.014) on serum 25(OH)D between the three independent variables, with the vitamin D oral contraception group having significantly greater serum 25(OH)D increases (from 45.9 to 98.3 nmol/L) compared with those not taking oral contraception (44.2 - 69.6 nmol/L) (P = 0.019). Conclusions: The estrogen-containing oral contraception increases serum 25(OH)D in premenopausal women with a magnified effect in those taking vitamin D supplementation. Future studies need to examine the relationship between estrogen, vitamin D supplementation, serum 25(OH)D, 1,25(OH)D, parathyroid hormone and other markers of bone metabolisms. J Endocrinol Metab. 2017;7(4):117-121 doi: https://doi.org/10.14740/jem441w
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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 | 0.004 | 0.005 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.006 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.004 | 0.002 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
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".