BACKGROUND Riboflavin, vitamin B-6, and vitamin B-12 are key players in one-carbon metabolism as enzymatic cofactors, and deficiency of these nutrients may influence reproductive outcomes possibly through affecting reproductive hormones. OBJECTIVE The goal was to investigate associations between dietary intakes of riboflavin, vitamin B-6, and vitamin B-12, and menstrual function among premenopausal women. DESIGN This was a secondary analysis of a prospective cohort study conducted at the University at Buffalo during 2005 to 2007. PARTICIPANTS/SETTING Participants were 259 healthy, regularly menstruating women (aged 18 to 44 years) with self-reported menstrual cycles between 21 and 35 days, who were not trying to conceive, and who had not used hormonal contraception during the past 3 months. MAIN OUTCOME MEASURES Intakes of B vitamins were assessed via 24-hour dietary recalls four times per menstrual cycle for two cycles. Serum reproductive hormones and plasma homocysteine were measured eight and three times, respectively, per cycle for two cycles. Anovulatory cycles were determined by progesterone concentrations ≤5 ng/mL (15.9 nmol/L) and no observed serum luteinizing hormone peak during the mid or late luteal phase visit. STATISTICAL ANALYSIS Weighted linear mixed regressions were used to evaluate associations between cycle-averaged B vitamin intakes and hormones and homocysteine, and generalized linear regressions for associations with anovulation. Models were adjusted for age, race, body mass index, physical activity, alternate Mediterranean diet score, intakes of total energy, protein, fiber, and folate, and percentage of energy intake from fat. RESULTS Higher intakes of riboflavin (per 0.1 mg increase in intake) were inversely correlated with estradiol (-0.87%, 95% CI -1.67 to -0.06) and homocysteine levels (-0.61%, 95% CI -1.10 to -0.12). Higher vitamin B-6 intakes were suggestive of higher follicle-stimulating hormone, although the results were not statistically significant (0.63% difference, 95% CI -0.03 to 1.29, per 0.1 mg increase in intake; P=0.06). Small increases in testosterone and decreases in homocysteine were found with vitamin B-12 intake. No associations were observed between intake of B vitamins and a risk of sporadic anovulation. CONCLUSIONS Higher intakes of riboflavin were associated with a small decrease in serum estradiol among healthy, regularly menstruating women. Higher intakes of riboflavin and vitamin B-12 were associated with lower plasma homocysteine concentrations. Overall, riboflavin, vitamin B-6, and vitamin B-12 that are one-carbon nutrients do not appear to influence the ovarian cycle among premenopausal women.

中文翻译：

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绝经前妇女的维生素 B-2（核黄素）、维生素 B-6 和维生素 B-12 的膳食摄入量和卵巢周期功能

背景核黄素、维生素B-6和维生素B-12作为酶辅助因子是一碳代谢的关键参与者，这些营养素的缺乏可能通过影响生殖激素而影响生殖结果。目的 目的是调查核黄素、维生素 B-6 和维生素 B-12 的膳食摄入量与绝经前妇女的月经功能之间的关联。设计 这是对 2005 年至 2007 年在布法罗大学进行的前瞻性队列研究的二次分析。 参与者/环境 参与者是 259 名健康、定期月经的女性（18 至 44 岁），她们自我报告的月经周期在 21 至 35 岁之间天，谁不想怀孕，谁在过去 3 个月内没有使用激素避孕。主要观察指标 通过 24 小时饮食回顾，每个月经周期四次评估 B 族维生素的摄入量，持续两个周期。血清生殖激素和血浆同型半胱氨酸分别测量 8 次和 3 次，每个周期为两个周期。无排卵周期由黄体酮浓度≤ 5 ng/mL (15.9 nmol/L) 和在黄体期中期或晚期就诊期间未观察到血清促黄体激素峰值确定。统计分析 加权线性混合回归用于评估周期平均 B 族维生素摄入量与激素和同型半胱氨酸之间的关联，以及与无排卵关联的广义线性回归。模型根据年龄、种族、体重指数、身体活动、替代地中海饮食评分、总能量、蛋白质、纤维和叶酸的摄入量进行了调整，和从脂肪中摄取能量的百分比。结果 较高的核黄素摄入量（每增加 0.1 毫克摄入量）与雌二醇（-0.87%，95% CI -1.67 至 -0.06）和同型半胱氨酸水平（-0.61%，95% CI -1.10 至 -0.12）呈负相关。较高的维生素 B-6 摄入量表明促卵泡激素较高，但结果无统计学意义（0.63% 差异，95% CI -0.03 至 1.29，每增加 0.1 毫克摄入量；P=0.06）。发现维生素 B-12 摄入量小幅增加睾酮和同型半胱氨酸。未观察到 B 族维生素的摄入与散发性无排卵风险之间存在关联。结论：在健康、有规律的月经期妇女中，较高的核黄素摄入量与血清雌二醇的小幅下降有关。较高的核黄素和维生素 B-12 摄入量与较低的血浆同型半胱氨酸浓度有关。总体而言，作为一碳营养素的核黄素、维生素 B-6 和维生素 B-12 似乎不会影响绝经前女性的卵巢周期。