Intergenotypic variation of Vitamin B12 and Folate in AD: In north indian population

Objectives:

Changes in lifestyle habits such as diet modification or supplementation have been indicated as probable protective factors for a number of chronic conditions including Alzheimer''s disease (AD). With this background, we aim to hypothesize that whether C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene contributes towards the risk of developing AD and its association with vitamin B12 and folate levels.

Materials and Methods:

A case-control study comprising of total 200 subjects, within the age group of 50-85 years. Their blood samples were analyzed for serum folate, vitamin B12 levels, and MTHFR C677T polymorphism by restriction fragment length polymorphism (RFLP).

Results:

The mean plasma levels of vitamin B12 and folate were significantly lower in study group when compared to the control group (P < 0.001). Genotypic and allelic frequency of MTHFR gene in both groups was found to be significant (P < 0.05). The intergenotypic variations of vitamin B12 and folate were found to be significant (P < 0.001).

Conclusion:

We concluded that the subjects with homozygous mutated alleles are more prone to AD and also pointed out the influence of presence/absence of MTHFR T allelic variants on serum folate and vitamin B12 levels.     

Vitamin B12 concentrations in psychiatric patients.

In an attempt to evaluate the possible relationship between vitamin B12 deficiency and mental disease, the blood content of vitamin B12 was investigated in 835 consecutive psychiatric patients. Low serum vitamin B12 values were found in approximately 10% of these patients, due to latent pernicious anaemia in one case, post-gastrectomy in seven cases and small intestinal resection in one case. In the remaining 72 cases vitamin B12 deficiency was probably caused by nutritional insufficiency. After correction of the dietary defect there was a spontaneous increase in serum vitamin B12 in 75% of these patients. No specific psychiatric syndrome was connected with hypovitaminosis B12, but a preponderance of arteriosclerotic dementia suggests that low serum vitamin B12 values are secondary to mental illness leading to apathy and loss of appetite. Most cases will recover without further vitamin B12 supplements. But some patients may need treatment because of severe mental and physical disabilities.     

Serum and Cerebrospinal Fluid Vitamin B12 Levels in Demented Patients with CH3—B12 Treatment—Preliminary Study—

Abstract: The vitamin B12 (VB12) parameter was studied in the serum and cerebrospinal fluid (CSF) of 14 demented patients. Eleven of these patients were in a state of dementia of the degenerative type such as Alzheimer's disease, senile dementia and Pick's disease. The serum VB12 concentration in all the patients was within normal limits, I.e. 500–1,300 pg/ml. There was no significant difference between the CSF-VBl2 levels and the severity of dementia. The serum and CSF-VB12 levels of the demented patients did not show any significant elevation after the oral administration of CH3–Bl2, 2 mg per day. On the other hand, there was a marked elevation of both the serum and CSF-VB12 after an oral medication (2 mg per day) plus intramuscular administrations (500 μg per day). These results confirm that the intramuscular administration of CH3–B12 is an effective way to get a higher value of the serum and CSF-VB12 levels.     

Folate, vitamin B12 and cognitive impairment in patients with Alzheimer's disease.

This study examines the relationship between folate, vitamin B12 and severity of cognitive impairment in patients with Alzheimer's disease (AD) as compared with other disorders associated with cognitive impairment. The patients were 97 consecutive referrals to an AD clinic. Forty patients had either possible or probable AD, 31 had other dementias (OD) and 26 had mild cognitive impairment (cognitively impaired, not demented; CIND). Patients had blood drawn for serum, red cell folate and B12, as well as other biochemical indicators of nutrition, within 24 h of the Mini-Mental State Examination (MMSE). In the AD group, only B12 was significantly correlated with MMSE. Using regression analysis, B12 contributed significantly to variance in MMSE. There was no correlation between MMSE and serum, red cell folate or B12 in the OD or CIND group and no significant correlation between MMSE and other nutritional indices in any group. These findings suggest the possibility of a specific relationship between B12 levels and severity of cognitive impairment in patients with AD.     

Folate and B12 serum levels in association with depression in the aged: a systematic review and meta-analysis

Objectives: To systematically review and meta-analyse existing evidence on the association between folate/B12, and depression among the aged people.

Methods: Following PRISMA/STROBE guidelines, the Medline abstracts were retrieved using an algorithm comprising relevant MeSH terms. Publications on the association of folate/B12 serum measurements with depression were abstracted independently by two reviewers and included in both gender and gender-specific meta-analyses, following recarculations of published data as appropriate. The Newcastle-Ottawa scale was used to evaluate the quality of included studies.

Results: Both gender data were contributed by 11 folate-related (7949 individuals) and 9 B12-related studies (6308 individuals), whereas gender-specific data by 4 folate-related (3409 individuals) and 3 B12-related studies (1934 individuals). A statistically significant overall association between both exposures of interest (low folate and B12 levels) and depression was observed (OR_folate:1.23, 95%CI:1.07–1.43, OR_B12:1.20, 95%CI:1.02–1.42). Gender-specific estimates pointed to a statistically significant positive association between low B12 levels and depression only among women (OR:1.33, 95%CI:1.02–1.74); the gender specific associations of low folate levels with depression were, however, non-significant and of counter-direction (OR_females:1.37, 95%CI:0.90–2.07; OR_males:0.84, 95%CI:0.57–1.25).

Conclusion: Low folate and B12 serum levels seem to be associated with depression in the aged. The gender-specific analyses are confined to a positive association of low B12 with depression among older women and call for further research in this direction.     

脊髓亚急性联合变性患者血清维生素B_(12)水平与临床表现的分析

目的探讨脊髓亚急性联合变性(SCD)患者的血清维生素B_(12)水平(正常或降低)与临床表现间的关系。方法回顾性分析18例血清维生素B_(12)水平降低的SCD患者(维生素B_(12)降低组)和12例维生素B_(12)水平正常或升高的SCD患者(维生素B_(12)正常组)的临床资料,比较两组在临床表现、血液学、电生理、影像及维生素B_(12)治疗效果方面的差异。结果 1维生素B_(12)降低组患者肌力较维生素B_(12)正常组显著减退(P=0.002);2维生素B_(12)降低组同型半胱氨酸(Hcy)平均值较正常组高,且Hcy升高比例高于维生素B_(12)正常组(P=0.020);3维生素B_(12)降低组的体感诱发电位异常率高于维生素B_(12)正常组(P=0.044);4两组脊髓MRI阳性发现率差异无显著性;5维生素B_(12)降低组对维生素B_(12)治疗效果好于维生素B_(12)正常组(P=0.006)。结论血清维生素B_(12)水平降低的SCD患者较维生素B_(12)水平正常患者病情更为严重;维生素B_(12)水平降低患者应用维生素B_(12)治疗的效果更好;血清维生素B_(12)降低不是诊断SCD的必要条件;高Hcy并非一项理想的SCD诊断指标;SCD的预后、疗效与病程有关,早期诊断、及时治疗至关重要。     

同型半胱氨酸与兔脑动脉损伤的关系及维生素B6、B12、叶酸对其预防作用的探讨

目的探讨高蛋氨酸(Met)喂饲兔引发高同型半胱氨酸(Hcy)血症与脑动脉损伤的关系,同时观察补充VitB6、VitB12、叶酸对血Hcy水平和动脉损伤的影响.方法采用纯种雄性新西兰兔26只,分为三组对照组、高蛋氨酸组、干预组,分别喂以普通兔饲料每只200g/d、普通饲料添加0.5%Met、普通饲料每天每只兔添加0.5%Met、叶酸2.5mg、VitB6 10mg、VitB12 200mg,喂养6个月,测定血浆总Hcy(tHcy),光镜检测脑动脉组织学改变.结果实验前血浆tHcy浓度三组间无明显差异,实验后断食2 h和7 h血tHcy浓度高Met组明显高于对照组(P＜0.01),而干预组血tHcy浓度明显低于高Met组(P＜0.01),但仍高于对照组.光镜组织学检测发现高Met组和干预组脑动脉可见内皮细胞坏死、脱落、溃疡形成,附壁血栓,中膜平滑肌散乱疏松.结论高Met引发高Hcy血症对脑动脉有损伤,且VitB6、VitB12、叶酸的补充可以降低高Met引发的高Hcy浓度的水平.     

Vitamin B complex and vitamin B12 levels after peripheral nerve injury

The aim of the present study was to evaluate whether tissue levels of vitamin B complex and vitamin B12 were altered after crush-induced peripheral nerve injury in an experimental rat model. A total of 80 male Wistar rats were randomized into one control (n = 8) and six study groups (1, 6, 12, 24 hours, 3, and 7 days after experimental nerve injury;n = 12 for each group). Crush-induced peripheral nerve injury was per-formed on the sciatic nerves of rats in six study groups. Tissue samples from the sites of peripheral nerve injury were obtained at 1, 6, 12, 24 hours, 3 and 7 days after experimental nerve injury. Enzyme-linked immunosorbent assay results showed that tissue levels of vitamin B complex and vitamin B12 in the injured sciatic nerve were signiifcantly greater at 1 and 12 hours after experimental nerve injury, while they were signiifcantly lower at 7 days than in control group. Tissue level of vitamin B12 in the injured sciatic nerve was signiifcantly lower at 1, 6, 12 and 24 hours than in the control group. These results suggest that tissue levels of vitamin B complex and vitamin B12 vary with progression of crush-induced peripheral nerve injury, and supplementation of these vitamins in the acute period may be beneficial for acceleration of nerve regeneration.     

Vitamin B12 and folic acid serum levels in obsessive compulsive disorder

Vitamin B12 and folate serum levels were studied in 30 patients with obsessive compulsive disorder (OCD), and in two control groups comprised of 30 chronic schizophrenics and 30 normal healthy subjects. Six patients (20%) of the OCD group had abnormal low levels of vitamin B12. This prevalence was significantly higher than that of the control groups. No clinical neurological or haematological abnormalities accompanied the reduced vitamin B12 levels. Possible implication of this finding for the pathophysiology of OCD in a subgroup of patients and the possibility that the B12 deficiency could be the consequence rather than the cause of OCD are suggested.