Division of Epidemiology, Statistics, and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, USA.
PLoS One. 2012;7(9):e46276. doi: 10.1371/journal.pone.0046276. Epub 2012 Sep 26.
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.
叶酸被推荐给育龄妇女以预防出生缺陷，但对于饮食摄入对其他生殖结果的影响知之甚少。叶酸补充剂的使用已被证明可以提高妊娠率，这表明它可能与排卵有关，但研究有限。我们的目的是评估饮食叶酸摄入量、激素水平与健康、规律月经妇女散发性排卵障碍之间的关系。
方法/主要发现：BioCycle 研究（2005-2007 年）前瞻性地随访了来自纽约西部地区的 259 名 18-44 岁的健康女性，随访时间最长达 2 个月经周期。通过 24 小时回忆，在每个周期内最多 4 次评估总叶酸和特定叶酸来源。在每个周期内最多 8 次测量血清中的雌二醇、孕酮、促黄体生成素和卵泡刺激素，使用生育监测器定时测量。排卵障碍定义为周期中黄体中期峰值孕酮浓度≤5ng/ml且无 LH 峰。饮食叶酸摄入量（以膳食当量计）在三分位组之间呈边际显著与黄体中期孕酮水平升高相关（趋势 P=0.08）。合成叶酸的摄入量与黄体中期孕酮水平显著相关（趋势 P=0.05）。具体而言，与第 1 分位组相比，第 3 分位组的合成叶酸摄入量平均高出 16.0%（95%CI，0.5-33.8%）的黄体中期孕酮水平。此外，合成叶酸的消耗与排卵障碍呈显著负相关，与第 1 分位组相比，第 3 分位组排卵障碍的几率降低了 64%（95%CI，8-86%）（趋势 P=0.03）。
结论/意义：这些发现表明，富含合成叶酸的饮食可能与孕酮水平升高和散发性排卵障碍风险降低有关。进一步研究饮食叶酸和叶酸补充剂对生殖健康的影响是必要的。
