Different vitamin B12 and folic acid concentrations could exacerbate the immune response. The aim was to evaluate different dietary folic acid and vitamin B12 levels on the immune response in aged rats. Male Sprague Dawley aged rats were assigned to three folic acid groups (deficient, control, supplemented) each in absence of vitamin B12 for 30 days. Several parameters of innate and acquired im...

BACKGROUND Supplementation with B vitamins for stroke prevention has been evaluated over the years, but which combination of B vitamins is optimal for stroke prevention is unclear. We performed a network meta-analysis to assess the impact of different combinations of B vitamins on risk of stroke. METHODS A total of 17 trials (86 393 patients) comparing 7 treatment strategies and placebo were ...

BACKGROUND AND PURPOSE Blood-brain barrier dysfunction may be an early phenomenon in the development of the small vessel disease, which underlies white matter lesions. Because vitamin B12 plays a role in maintaining the integrity of the blood-brain barrier, we studied serum vitamin B12 level in relation to such lesions. METHODS In 124 patients with first lacunar stroke, we measured serum vita...

Only a small fraction of vitamin B12-requiring organisms are able to synthesize B12 de novo, making it a common commodity in microbial communities. Initially recognized as an enzyme cofactor of a few enzymes, recent studies have revealed additional B12-binding enzymes and regulatory roles for B12 Here we report the development and use of a B12-based chemical probe to identify B12-binding protei...

Vitamin B12 (cobalamin) deficiency is a major public health problem, particularly among the elderly population. It is known that a deficiency in serum B12 levels can cause a combination of neurological and psychiatric disorders. Therefore, in these cases successful replacement of depleted B12 levels is a necessity. Identification of B12 deficiency in elderly patients can be rather difficult as ...

Vitamin B12 (cobalamin, Cbl, B12) is an indispensable water-soluble micronutrient that serves as a coenzyme for cytosolic methionine synthase (MS) and mitochondrial methylmalonyl-CoA mutase (MCM). Deficiency of Cbl, whether nutritional or due to inborn errors of Cbl metabolism, inactivate MS and MCM leading to the accumulation of homocysteine (Hcy) and methylmalonic acid (MMA), respectively. In...

Although methylenetetrahydrofolate reductase, a folate enzyme gene, has been associated with idiopathic male infertility, few studies have examined other folate-related metabolites and genes. We investigated whether idiopathic male infertility is associated with variants in folate, vitamin B(12) (B12) and total homocysteine (tHcy)-related genes and measured these metabolites in blood. We conduc...

Vitamin B12 (B12) belongs to a group of water soluble B-vitamins. Methylcobalamin and adenosylcobalamin are two biologically active forms of B12. Hydroxocobalamin, aquacobalamin, nitrocobalamin and cyanocobalamin are metabolized to either of the two active forms once ingested. B12 is essential in synthesis of methionine (methylcobalamin) and in metabolism of lipids, protein and carbohydrates (a...

A dual isotope vitamin B12 absorption test in which vitamin B12 is given both in aqueous solution and bound to protein (chicken serum), was evaluated in 26 controls and 68 patients with subnormal serum vitamin B12 concentrations (19 with pernicious anaemia, 13 with iron deficiency, seven after partial gastrectomy, seven with malabsorptive states, five with folate deficiency, four with chronic a...

INTRODUCTION Osteoporosis and vitamin B12 deficiency are conditions with an increasing prevalence over time. It has been described an association between low serum vitamin B12, osteoporosis and increased risk of bone fractures, but the studies are heterogeneous and the results are controversial. OBJECTIVE To investigate the association between plasma levels of vitamin B12 and bone mineral den...