Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Context: Small studies suggest exogenous estrogen may improve vitamin D status, but the etiology is unclear because women who use hormones may make lifestyle choices that differentially affect vitamin D status.', 'Our objective was to investigate the association between use of hormonal contraception and 25-hydroxy-vitamin D (25(OH)D).', 'We used linear regression modeling of cross-sectional data to estimate percent change in season-adjusted serum 25(OH)D with estrogen use after adjustment for other factors.', 'At the enrollment clinic visit (2010-2012) into a cohort study of uterine fibroids, each subject provided a blood sample, had anthropomorphic variables and skin reflectance measured, and answered questionnaires on demographics, dietary and supplement intake, contraceptive use, reproductive and medical history, and behaviors.', 'A total of 1662 African American women, community volunteers, 23-34 years old, living in the Detroit, Michigan, area were included.', 'None.', 'Serum 25(OH)D was measured.', 'Serum 25(OH)D concentrations were low (70% <20 ng/ml). Current use of an estrogen-containing contraceptive was associated with a 20% (95% confidence interval: 14-27) increase in 25(OH)D after adjustment. There was no increase in 25(OH)D among participants who had used estrogen in the past, but were not current users, indicating that results were unlikely to be due to unmeasured confounding by factors related to contraceptive choice.
Answer: The increase in 25(OH)D with use of estrogen-containing contraceptives raise mechanistic questions regarding the biological pathways involved, and highlights the need for studies that examine possible endogenous estrogen effects on vitamin D.
Does use of Estrogen-Containing Contraception be Associated With Increased Concentrations of 25-Hydroxy Vitamin D?

Context: Despite their high prevalence, sleep disorders often remain unrecognized and untreated because of barriers to assessment and management. The aims of the present study were to examine associations of complaints of sleep disturbances with cardiovascular disease, related risk factors, and inflammation in the community and to determine the contribution of sleep disturbances to self-perceived physical health.', 'The sample consists of n=10.000 participants, aged 35 to 74 years of a population based community sample in Germany. Cross-sectional associations of complaints of sleep disturbances with cardiovascular risk factors and disease, biomarkers of inflammation, depression, anxiety, and physical health status were analyzed.', '19% of our sample endorsed clinically significant sleep disturbances. In the unadjusted analyses severity of sleep disturbances increased with female sex, low socioeconomic status, living without a partnership, cardiovascular disease, depression, anxiety, poor physical health, increased levels of C-reactive protein and fibrinogen. After multivariate adjustment robust associations with coronary heart disease, myocardial infarction and dyslipidemia remained. Complaints of sleep disturbances were strong and independent contributors to self-perceived poor physical health beyond depression, anxiety and medical disease burden.
Answer: Given the high prevalence of complaints of sleep disturbances and their strong impact on health status, increased efforts should be undertaken for their identification and treatment.
Are complaints of sleep disturbances associated with cardiovascular disease : results from the Gutenberg Health Study?

Context: The objectives were to analyze the cardiac effects of exposure to tobacco smoke (ETS), for a period of 30 days, alone and in combination with beta-carotene supplementation (BC).', 'Rats were allocated into: Air (control, n = 13); Air + BC (n = 11); ETS (n = 11); and BC + ETS (n = 9). In Air + BC and BC + ETS, 500 mg of BC were added to the diet. After three months of randomization, cardiac structure and function were assessed by echocardiogram. After that, animals were euthanized and morphological data were analyzed post-mortem. One-way and two-way ANOVA were used to assess the effects of ETS, BC and the interaction between ETS and BC on the variables.', 'ETS presented smaller cardiac output (0.087 +/- 0.001 vs. 0.105 +/- 0.004 l/min; p = 0.007), higher left ventricular diastolic diameter (19.6 +/- 0.5 vs. 18.0 +/- 0.5 mm/kg; p = 0.024), higher left ventricular (2.02 +/- 0.05 vs. 1.70 +/- 0.03 g/kg; p < 0.001) and atrium (0.24 +/- 0.01 vs. 0.19 +/- 0.01 g/kg; p = 0.003) weight, adjusted to body weight of animals, and higher values of hepatic lipid hydroperoxide (5.32 +/- 0.1 vs. 4.84 +/- 0.1 nmol/g tissue; p = 0.031) than Air. However, considering those variables, there were no differences between Air and BC + ETS (0.099 +/- 0.004 l/min; 19.0 +/- 0.5 mm/kg; 1.83 +/- 0.04 g/kg; 0.19 +/- 0.01 g/kg; 4.88 +/- 0.1 nmol/g tissue, respectively; p > 0.05). Ultrastructural alterations were found in ETS: disorganization or loss of myofilaments, plasmatic membrane infolding, sarcoplasm reticulum dilatation, polymorphic mitochondria with swelling and decreased cristae. In BC + ETS, most fibers showed normal morphological aspects.
Answer: One-month tobacco-smoke exposure induces functional and morphological cardiac alterations and BC supplementation attenuates this ventricular remodeling process.
Does beta-carotene supplementation attenuate cardiac remodeling induced by one-month tobacco-smoke exposure in rats?