Adams James B, George Frank, Audhya T
Arizona State University, Tempe, AZ 85287-6006, USA.
J Altern Complement Med. 2006 Jan-Feb;12(1):59-63. doi: 10.1089/acm.2006.12.59.
There have been many studies of the effect of high-dose supplementation of vitamin B6 on children and adults with autism, with all but one reporting benefits.
The aim of this study was to investigate the biochemical basis for vitamin B6 therapy by measuring the level of total vitamin B6 in the plasma of unsupplemented children with autism spectrum disorder compared to unsupplemented control subjects.
Children with autism spectrum disorders (n = 35, age 3-9 years) and unrelated typical children (n = 11, age 6-9 years), all from Arizona, were studied. (This includes the data from 24 children with autism from our previous study.)
A microbiologic assay was used to measure the level of total vitamin B6 (including phosphorylated and unphosphorylated forms), in a blinded fashion.
Children with autism had a 75% higher level of total vitamin B6 than the controls (medians of 56 versus 32 ng/mL, respectively, p = 0.00002). Most of the autistic children (77%) had levels that were more than 2 standard deviations above the median value of the controls. The autistic girls (n = 5) also had elevated levels (mean of 54.6 ng/mL, median of 60 ng/mL).
These results are consistent with previous studies that found that: (1) pyridoxal kinase had a very low activity in children with autism and (2) pyridoxal 5 phosphate (PLP) levels are unusually low in children with autism. Thus, it appears that the low conversion of pyridoxal and pyridoxine to PLP results in low levels of PLP, which is the active cofactor for 113 known enzymatic reactions, including the formation of many key neurotransmitters.
Total vitamin B6 is abnormally high in autism, consistent with previous reports of an impaired pyridoxal kinase for the conversion of pyridoxine and pyridoxal to PLP. This may explain the many published studies of benefits of high-dose vitamin B6 supplementation in some children and adults with autism.
已有多项关于大剂量补充维生素B6对自闭症儿童和成人影响的研究，除一项研究外，其他研究均报告了有益效果。
本研究旨在通过测量未补充维生素B6的自闭症谱系障碍儿童与未补充维生素B6的对照受试者血浆中总维生素B6的水平，来探究维生素B6治疗的生化基础。
研究了来自亚利桑那州的自闭症谱系障碍儿童（n = 35，年龄3 - 9岁）和无关的正常儿童（n = 11，年龄6 - 9岁）。（这包括我们之前研究中24名自闭症儿童的数据。）
采用微生物学测定法以盲法测量总维生素B6（包括磷酸化和未磷酸化形式）的水平。
自闭症儿童的总维生素B6水平比对照组高75%（中位数分别为56 ng/mL和32 ng/mL，p = 0.00002）。大多数自闭症儿童（77%）的水平高于对照组中位数的2个标准差以上。自闭症女孩（n = 5）的水平也有所升高（平均值为54.6 ng/mL，中位数为60 ng/mL）。
这些结果与之前的研究一致，之前的研究发现：（1）自闭症儿童中吡哆醛激酶活性非常低；（2）自闭症儿童中磷酸吡哆醛（PLP）水平异常低。因此，似乎吡哆醛和吡哆醇向PLP的低转化率导致PLP水平较低，而PLP是113种已知酶促反应的活性辅因子，包括许多关键神经递质的形成。
自闭症患者的总维生素B6异常高，这与之前关于吡哆醛激酶将吡哆醇和吡哆醛转化为PLP受损的报道一致。这可能解释了许多已发表的关于大剂量补充维生素B6对一些自闭症儿童和成人有益的研究。
