Dataset Information

The impact of dietary folate intake on reproductive function in premenopausal women: a prospective cohort study.

ABSTRACT:

Background

Folic acid is recommended to reproductive-aged women to prevent birth defects, though little is known about the effects of dietary intake on other reproductive outcomes. Improved pregnancy rates have been documented after folic acid supplement use, suggesting a possible link with ovulation, however research is limited. Our objective was to evaluate the association between dietary folate intake, hormone levels, and sporadic anovulation in healthy, regularly menstruating women.

Methodology/principal findings

The BioCycle study (2005-2007) prospectively followed 259 healthy women aged 18-44 years from the western New York region for up to 2 menstrual cycles. Total folate and specific sources of folate were assessed up to 4 times per cycle by 24-hour recall. Estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were measured in serum up to 8 times per cycle, timed using fertility monitors. Anovulation was defined as a cycle with peak progesterone concentration ? 5 ng/mL and no LH peak in the mid/late luteal phase. Higher intake of dietary folate (in dietary equivalents) across tertiles had a marginally significant association with greater luteal progesterone levels (P trend 0.08). Higher intake of synthetic folate was significantly associated with higher luteal progesterone levels (P trend 0.05). Specifically, women in the 3(rd) tertile of synthetic folate intake had, on average, 16.0% (95% CI, 0.5-33.8%) higher luteal progesterone levels compared to women in the 1(st) tertile. Moreover, consumption of synthetic folate was significantly and inversely associated with anovulation such that women in the 3(rd) tertile had a 64% (95% CI, 8-86%) decreased odds of anovulation compared to the women in the 1(st) tertile (P trend 0.03).

Conclusions/significance

These findings suggest that a diet high in synthetic folate may be associated with increased progesterone levels and lower risk of sporadic anovulation. Further study of the effect of dietary folate and folic acid supplement use on reproductive health is warranted.

SUBMITTER: Gaskins AJ

PROVIDER: S-EPMC3458830 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The impact of dietary folate intake on reproductive function in premenopausal women: a prospective cohort study.

Gaskins Audrey J AJ Mumford Sunni L SL Chavarro Jorge E JE Zhang Cuilin C Pollack Anna Z AZ Wactawski-Wende Jean J Perkins Neil J NJ Schisterman Enrique F EF

PloS one 20120926 9

<h4>Background</h4>Folic acid is recommended to reproductive-aged women to prevent birth defects, though little is known about the effects of dietary intake on other reproductive outcomes. Improved pregnancy rates have been documented after folic acid supplement use, suggesting a possible link with ovulation, however research is limited. Our objective was to evaluate the association between dietary folate intake, hormone levels, and sporadic anovulation in healthy, regularly menstruating women.< ...[more]

PMID: 23050004

Similar Datasets

Project description:BACKGROUND: Health authorities in numerous countries recommend periconceptional folic acid to pregnant women to prevent neural tube defects. The objective of this study was to examine the association of folic acid supplementation during different periods of pregnancy and of dietary folate intake with the risk of spontaneous preterm delivery (PTD). METHODS: The Norwegian Mother and Child Cohort Study is a population-based prospective cohort study. A total of 65,668 women with singleton pregnancies resulting in live births in 1999-2009 were included. Folic acid supplementation was self-reported from 26 weeks before pregnancy until week 24 during pregnancy. At gestational week 22, the women completed a food frequency questionnaire, which allowed the calculation of their average total folate intake from foods and supplements for the first 4-5 months of pregnancy. Spontaneous PTD was defined as the spontaneous onset of delivery between weeks 22+0 and 36+6 (n?=?1,628). RESULTS: The median total folate intake was 266 ?g/d (interquartile range IQR 154-543) in the overall population and 540 ?g/d (IQR 369-651) in the supplement users. Eighty-three percent reported any folic acid supplementation from <8 weeks before to 24 weeks after conception while 42% initiated folic acid supplementation before their pregnancy. Cox regression analysis showed that the amount of folate intake from the diet (hazard ratio HR 1.16; confidence interval CI 0.65-2.08) and from the folic acid supplements (HR 1.04; CI 0.95-1.13) was not significantly associated with the risk of PTD. The initiation of folic acid supplementation more than 8 weeks before conception was associated with an increased risk for PTD (HR 1.19; CI 1.05-1.34) compared to no folic acid supplementation pre-conception. There was no significant association with PTD when supplementation was initiated within 8 weeks pre-conception (HR 1.01; CI 0.88-1.16). All analyses were adjusted for maternal characteristics and socioeconomic, health and dietary variables. CONCLUSIONS: Our findings do not support a protective effect of dietary folate intake or folic acid supplementation on spontaneous PTD. Pre-conceptional folic acid supplementation starting more than 8 weeks before conception was associated with an increased risk of PTD. These results require further investigation before discussing an expansion of folic acid supplementation guidelines.

Project description:ObjectivesAmong hemodialysis patients, clinical practice guidelines recommend dietary potassium restriction given concerns about potential hyperkalemia leading to malignant arrhythmias and mortality. However, there are sparse data informing recommendations for dietary potassium intake in this population. We thus sought to examine the relationship between dietary potassium intake and death risk in a prospective cohort of hemodialysis patients.Design and methodsAmong 415 hemodialysis patients from the prospective "Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease" cohort recruited across 16 outpatient dialysis clinics, information regarding dietary potassium intake was obtained using Food Frequency Questionnaires administered over October 2011 to March 2015. We first examined associations of baseline dietary potassium intake categorized as tertiles with mortality risk using Cox regression. We then examined clinical characteristics associated with low dietary potassium intake (defined as the lowest tertile) using logistic regression.ResultsIn expanded case-mix Cox analyses, patients whose dietary potassium intake was in the lowest tertile had higher mortality (ref: highest tertile) (adjusted hazard ratio 1.74, 95% confidence interval 1.14-2.66). These associations had even greater magnitude of risk following adjustment for laboratory and nutritional covariates (adjusted hazard ratio 2.65, 95% confidence interval 1.40-5.04). In expanded case-mix restricted cubic spline analyses, there was a monotonic increase in mortality risk with incrementally lower dietary potassium intake. In expanded case-mix logistic regression models, female sex; higher serum bicarbonate; and lower dietary energy, protein, and fiber intake were associated with low dietary potassium intake.ConclusionsIn a prospective cohort of hemodialysis patients, lower dietary potassium intake was associated with higher mortality risk. These findings suggest that excessive dietary potassium restriction may be deleterious in hemodialysis patients, and further studies are needed to determine the optimal dietary potassium intake in this population.

Project description:BackgroundIn younger individuals, dietary nitrate supplementation has been shown to improve short-term vascular and muscle function. The role of higher habitual nitrate intake as part of a typical diet on muscle function in ageing has not been investigated. A cross-sectional study of relationships between dietary nitrate and measures of muscle function in older community-dwelling Australian women (n = 1420, ≥70 years) was undertaken.MethodsParticipants completed a semi-quantitative food frequency questionnaire assessing dietary intake over the previous year. Total nitrate from vegetables and non-vegetable sources was calculated from a validated instrument that quantified the nitrate content of food recorded within the food frequency questionnaire. Handgrip strength and timed-up-and-go (TUG) were assessed, representing muscle strength and physical function, respectively. Cut-points for weak grip strength (<22 kg) and slow TUG (>10.2 s) were selected due to their association with adverse outcomes. Linear and logistic regressions were used to examine the relationship between total nitrate intake and muscle function measures.ResultsMean ± standard deviation (SD) total nitrate intake was 79.5 ± 31.2 mg/day, of which 84.5% came from vegetables. Across the unadjusted tertiles of nitrate intake (<64.2 mg/day; 64.2 to <89.0 mg/day; ≥89.0 mg/day), women in the highest tertile had a 4% stronger grip strength and a 5% faster TUG performance compared with the lowest tertile. In multivariable-adjusted models, each SD higher nitrate intake (31.2 mg/day) was associated with stronger grip strength (per kilogram, β 0.31, P = 0.027) and faster TUG (per second, β -0.27, P = 0.001). The proportion of women with weak grip strength (<22 kg) or slow TUG (>10.2 s) was 61.0% and 36.9%, respectively. Each SD higher nitrate intake (31.2 mg/day) was associated with lower odds for weak grip strength (OR 0.84, 95% CI 0.74-0.95, P = 0.005) and slow TUG (OR 0.86, 95% CI 0.76-0.98, P = 0.021). Compared with women in the lowest tertile of nitrate intake, women in the highest nitrate intake tertile had lower odds for weak grip strength (OR 0.65, 95% CI 0.49-0.87, Ptrend= 0.004) and slow TUG (OR 0.72, 95% CI 0.53-0.97, Ptrend = 0.044).ConclusionsThis investigation highlights potential benefits of nitrate-rich diets on muscle strength and physical function in a large cohort of older women. Considering poor muscle strength and physical function is associated with a range of adverse health outcomes such as falling, fractures, cardiovascular disease, and mortality, increasing dietary nitrate, especially though vegetable consumption may be an effective way to limit age-related declines in muscle function.

Dataset Information

The impact of dietary folate intake on reproductive function in premenopausal women: a prospective cohort study.

Background

Methodology/principal findings

Conclusions/significance

Publications

The impact of dietary folate intake on reproductive function in premenopausal women: a prospective cohort study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure