Metformin treatment, both duration and dose, is associated with increased risk of vitamin B12 (B12) deficiency. B12 deficiency causes Hyperhomocysteinemia (HHcy), which is associated with an increased risk of a variety of diabetic co-morbidities. As a result, the newest “Standards of Medical Care in Diabetes 2017”, issued by the American Diabetes Association included a recommendation to periodi...

279 14.1 Role of vitamin B12 in human metabolic processes Although the nutritional literature still uses the term vitamin B12, a more specific name for vitamin B12 is cobalamin. Vitamin B12 is the largest of the B complex vitamins, with a relative molecular mass of over 1000. It consists of a corrin ring made up of four pyrroles with cobalt at the centre of the ring (1, 2). There are several vi...

In cobaiamin deficiency, inadequate DNA-thymine synthesis appears to resuit from decreased conversion of N5methyltetrahydrofolic acid to tetrahydrofo ic acid (THE). The N5-methyl THE conversion catalyzed by N5methyl THF-homocysteine methyltransferase requires a cobalamin coenzyme, presumed to be methylcobalamin (methyl-B12). In support of the above, in B12-deficient marrow cultures, methyl-B12 ...

Vitamin B12 deficiency is common in older people and is associated with cognitive impairment in the absence of anaemia or macrocytosis [1–3]. The prevalence of vitamin B12 deficiency increases in the elderly, mainly due to malabsorption of food-bound vitamin B12 due to atrophic gastritis that limits the ability of older people to release vitamin B12 from dietary sources in meat, fish and dairy ...

  Background :Hyperhomocysteinemia is a risk factor for cardiovascular disease particularly in patients with end stage renal disease (ESRD). Vitamin B12 supplementation on its own still remains as a controversial issue for clinicians in decreasing the level of homcysteine in this group of patients.   Methods : Using all randomized controlled trials (RCTs), clinical trials and pre-post-trial stu...

B12 deficiency is the leading cause of megaloblastic anemia, and although more common in the elderly, can occur at any age. Clinical disease caused by B12 deficiency usually connotes severe deficiency, resulting from a failure of the gastric or ileal phase of physiological B12 absorption, best exemplified by the autoimmune disease pernicious anemia. There are many other causes of B12 deficiency...

The vitamin B12 levels of cerebrospinal fluid were assayed microbiologically (Lactobacillus leichmannii method) using samples from 44 patients with various neurological disorders, 4 patients with megaloblastic anemia and 34 controls. Twenty-seven controls that did not receive vitamin B12 showed a mean cerebrospinal fluid vitamin B12 level of 21.5 pg/ml (range: 0-60). No decrease in cerebrospina...

Vitamin B12 (cobalamin) ranks among the most useful, safe and effective orthomolecules when treating a diverse array of neuropsychiatric conditions. However, most clinicians do not consider vitamin B12 important unless the serum level is below laboratory reference ranges. Ten research reports, summarized here, indicate metabolic consequences from low-normal (but not deficient) serum B12 levels,...

Vitamin B12 deficiency is widespread. Among the population groups at risk are older people, vegetarians, pregnant women and patients with renal or intestinal diseases. The neurological symptoms of vitamin B12 deficiency are unspecific and can be irreversible. Early detection is therefore important. This article reviews the diagnostic performance of the different laboratory markers for vitamin B...

Profound vitamin B12 deficiency is a known cause of disease, but the role of low or intermediate levels of B12 in the development of neuropathy and other neuropsychiatric symptoms as well as the relationship of eating meat and B12 levels is unclear. Here we use food-related internet search patterns from a sample of 8.5 million US-based people as a proxy to B12 intake and correlate these searche...