Vitamin B-Can it prevent cognitive decline? A systematic review and meta-analysis.

BACKGROUND: Development of cognitive decline represents substantial issues in today's society, steadily gaining importance with increasing life expectancy. One potential approach to preventing cognitive decline is to lower homocysteine by administering vitamin B. In this systematic review and meta-analysis, we address this topic and investigate whether oral supplementation of vitamin B can successfully prevent cognitive decline in cognitively unimpaired individuals. METHODS: A computerized systematic literature search was conducted using the electronic databases PubMed, Embase, and the Cochrane Library. Eligibility criteria included oral supplementation with vitamin B (B1, B6, folic acid, and B12) and the absence of cognitive impairment. A meta-analysis was conducted with "global cognition" as the primary outcome of this review. Secondary outcomes were changes in cognitive function in other cognitive domains reported in the included studies. Risk of bias was assessed according to the Cochrane Risk of Bias tool and the GRADE approach to establish the overall certainty of the evidence. RESULTS: The meta-analysis did not yield a significant overall effect of supplementation with vitamin B on cognitive function (Z = 0.87; p = 0.39; SMD, 0.02; 95% CI, - 0.034, 0.08). A sensitivity analysis focusing on specific risk factors did not alter this result. Some studies reported isolated significant effects of the intervention on secondary outcomes. However, these findings were outnumbered by the number of cognitive tests that did not yield significant effects. DISCUSSION: We found no overall evidence that oral vitamin B supplementation prevented cognitive decline. The isolated significant effects that were reported could be attributed to methodological issues. The results of this review do not provide evidence that population groups with certain risk factors would profit more from the intervention than others. Our findings do not apply to forms of administration other than oral supplementation nor do they offer information regarding the treatment of cognitively impaired individuals via the administration of vitamin B. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017071692.

Reducing unnecessary vitamin testing in general practice: barriers and facilitators according to general practitioners and patients.

OBJECTIVE: There has been an increase in testing of vitamins in patients in general practice, often based on irrational indications or for non-specific symptoms, causing increasing healthcare expenditures and medicalisation of patients. So far, there is little evidence of effective strategies to reduce this overtesting in general practice. Therefore, the aim of this qualitative study was to explore the barriers and facilitators for reducing the number of (unnecessary) vitamin D and B12 laboratory tests ordered. DESIGN AND SETTING: This qualitative study, based on a grounded theory design, used semistructured interviews among general practitioners (GPs) and patients from two primary care networks (147 GPs, 195 000 patients). These networks participated in the Reducing Vitamin Testing in Primary Care Practice (REVERT) study, a clustered randomized trial comparing two de-implementation strategies to reduce test ordering in primary care in the Netherlands. PARTICIPANTS: Twenty-one GPs, with a maximum of 1 GP per practice who took part in the REVERT study, and 22 patients (who were invited by their GP during vitamin-related consultations) were recruited, from which 20 GPs and 19 patients agreed to participate in this study. RESULTS: The most important factor hampering vitamin-test reduction programmes is the mismatch between patients and medical professionals regarding the presumed appropriate indications for testing for vitamin D and B12. In contrast, the most important facilitator for vitamin-test reduction may be updating GPs' knowledge about test indications and their awareness of their own testing behaviour. CONCLUSION: To achieve a sustainable reduction in vitamin testing, guidelines with clear and uniform recommendations on evidence-based indications for vitamin testing, combined with regular (individual) feedback on test-ordering behaviour, are needed. Moreover, the general public needs access to clear and reliable information on vitamin testing. Further research is required to measure the effect of these strategies on the number of vitamin test requests. TRIAL REGISTRATION NUMBER: WAG/mb/16/039555.

Degeneración combinada subaguda en un paciente sin anemia y con hipertensión severa / Subacute combined degeneration in a patient without anemia but with severe hypertension

RESUMEN La degeneración combinada subaguda, es una patología de tipo neuropsiquiatrica asociada al déficit de vitamina B12. Se manifiesta clínicamente por ataxia sensorial, neuropatía periférica, disfunción cognitiva y neuropatía óptica; estas manifestaciones generalmente son atribuidas a la síntesis anormal de mielina. Puede tener una presentación clínica inespecífica, pero la medición de los niveles de vitamina B12, algunos metabolitos séricos, y el uso de métodos de neuroimagen, ayudan a confirmar el diagnóstico ante su sospecha. A continuación se describe el caso de un paciente con un cuadro de degeneración combinada subaguda, quien consultó por síntomas neurológicos e hipertensión severa, quien luego del tratamiento presentó mejoría de su sintomatologia neurológica y vascular.

SUMMARY Sub-acute combined degeneration is a neuropsychiatrical pathology associated with vitamin B12 deficiency It is clinically manifested through sensorial ataxia, peripheral neuropathy, cognitive dysfunction and optical neuropathy; these manifestations are generally attributed to the abnormal synthesis of myelin. It can have a nonspecific clinical presentation but the measurement of the levels of vitamin B12, some serum metabolites, and the use of neuroimaging methods help to confirm the diagnose when suspected. The case of a patient with sub-acute combined degeneration is described below. The patient was attended because of neurological symptoms and severe hypertension, and after the treatment, the patient's neurological and vascular symptomatology improved.