Thaver D, Saeed M A, Bhutta Z A
Cochrane Database Syst Rev. 2006 Apr 19(2):CD000179. doi: 10.1002/14651858.CD000179.pub2.
Vitamin B6 plays vital roles in numerous metabolic processes in the human body, such as nervous system development and functioning. It has been associated with some benefits in non-randomised studies, such as higher Apgar scores, higher birthweights, and reduced incidence of pre-eclampsia and preterm birth. Recent studies also suggest a protection against certain congenital malformations.
To evaluate the clinical effects of vitamin B6 supplementation during pregnancy and/or labour.
We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 December 2005).
We included randomised controlled trials comparing vitamin B6 administration in pregnancy and/or labour with: placebos, no supplementations, or supplements not containing vitamin B6.
Two authors independently extracted data and assessed trials for methodological quality. We used relative risk and weighted mean difference with 95% confidence intervals.
Five trials (1646 women) were included. Four trials used blinding. One had adequate method of randomisation and allocation concealment; four did not report this. Three trials had large losses to follow up. Vitamin B6 as oral capsules or lozenges resulted in decreased risk of dental decay in pregnant women (capsules: relative risk (RR) 0.84; 95% confidence interval (CI) 0.71 to 0.98; one trial, n = 371; lozenges: RR 0.68; 95% CI 0.56 to 0.83; one trial, n = 342). A small trial showed reduced mean birthweights with vitamin B6 supplementation (weighted mean difference -0.23 kg; 95% CI -0.42 to -0.04; n = 33; one trial). We did not find any statistically significant differences in the risk of eclampsia (capsules: n = 1242; three trials; lozenges: n = 944; one trial), pre-eclampsia (capsules n = 1197; two trials; lozenges: n = 944; one trial) or low Apgar scores at one minute (oral pyridoxine: n = 45; one trial), between supplemented and non-supplemented groups. No differences were found in Apgar scores at one or five minutes, or breastmilk production between controls and women receiving oral (n = 24; one trial) or intramuscular (n = 24; one trial) loading doses of pyridoxine at labour.
AUTHORS' CONCLUSIONS: There were few trials, reporting few clinical outcomes and mostly with unclear trial methodology and inadequate follow up. There is not enough evidence to detect clinical benefits of vitamin B6 supplementation in pregnancy and/or labour other than one trial suggesting protection against dental decay. Future trials assessing this and other outcomes such as orofacial clefts, cardiovascular malformations, neurological development, preterm birth, pre-eclampsia and adverse events are required.
维生素B6在人体众多代谢过程中发挥着至关重要的作用，如神经系统的发育和功能。在非随机研究中，它已显示出一些益处，如更高的阿氏评分、更高的出生体重，以及子痫前期和早产发生率的降低。近期研究还表明其对某些先天性畸形具有保护作用。
评估孕期和/或分娩期间补充维生素B6的临床效果。
我们检索了Cochrane妊娠与分娩组试验注册库（2005年12月30日）。
我们纳入了比较孕期和/或分娩期间给予维生素B6与以下情况的随机对照试验：安慰剂、不补充、或不含维生素B6的补充剂。
两位作者独立提取数据并评估试验的方法学质量。我们使用相对风险和加权平均差以及95%置信区间。
纳入了五项试验（1646名女性）。四项试验采用了盲法。一项试验有充分的随机化和分配隐藏方法；四项试验未报告此情况。三项试验有大量失访。口服胶囊或含片形式的维生素B6可降低孕妇龋齿风险（胶囊：相对风险（RR）0.84；95%置信区间（CI）0.71至0.98；一项试验，n = 371；含片：RR 0.68；95% CI 0.56至0.83；一项试验，n = 342）。一项小型试验显示补充维生素B6后平均出生体重降低（加权平均差 -0.23 kg；95% CI -0.42至 -0.04；n = 33；一项试验）。我们未发现补充组与未补充组在子痫风险（胶囊：n = 1242；三项试验；含片：n = 944；一项试验）、子痫前期风险（胶囊n = 1197；两项试验；含片：n = 944；一项试验）或1分钟时低阿氏评分（口服吡哆醇：n = 45；一项试验）方面存在任何统计学显著差异。在1分钟或5分钟时的阿氏评分，或分娩时接受口服（n = 24；一项试验）或肌肉注射（n = 24；一项试验）负荷剂量吡哆醇的对照组与女性之间的母乳产量方面未发现差异。
试验较少，报告的临床结局较少，且大多试验方法不明且随访不足。除了一项试验提示对龋齿有保护作用外，没有足够证据证明孕期和/或分娩期间补充维生素B6有临床益处。未来需要进行评估此及其他结局（如口面部裂隙、心血管畸形、神经发育情况、早产、子痫前期和不良事件）的试验。
