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,...

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...

BACKGROUND The fraction of total plasma vitamin B(12) bound to transcobalamin (holoTC/B12 ratio) may reflect tissue levels of the vitamin, but its clinical relevance is unclear. METHODS We assessed associations between cognitive function and total B12, holoTC, and holoTC/B12 ratio in a cohort of elderly Latinos (n = 1089, age 60-101 years). We assessed cognitive function using the Modified Mi...

BACKGROUND Low vitamin B12 concentration in South Asian Indians is common, but the exact prevalence is not known. AIM To investigate prevalence and associations of low vitamin B12 concentration and hyperhomocysteinemia in rural and urban Indian men living in and around Pune, Maharashtra. METHOD We studied 441 middle-aged men (149 rural, 142 slum and 150 urban middle-class residents, mean ag...

Vitamin B12 deficiency is estimated to affect 10%-15% of people over the age of 60, and the laboratory diagnosis is usually based on low serum vitamin B12 levels or elevated serum methylmalonic acid and homocysteine levels. Although elderly people with low vitamin B12 status frequently lack the classical signs and symptoms of vitamin B12 deficiency, e.g. megaloblastic anemia, precise evaluation...

This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12) deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999-2002 National Health and Nutrition Examination Surveys (NHANES) were categorized in relation to three previously used definitions of B12 deficiency: (1) serum B12 < 148...

BACKGROUND Metformin, a standard therapy in type 2 diabetes, reduces vitamin B12 levels. Studies linking low vitamin B12 levels and cardiovascular disease are equivocal and suggest improving B12 levels may help in primary prevention. The role of vitamin B12 deficiency on cardiovascular risk factors, especially in type 2 diabetes has not been explored. The aim of this study is to investigate whe...

BACKGROUND Vitamin B12 deficiency is common in older people and the prevalence increases with age. Vitamin B12 deficiency may present as macrocytic anaemia, subacute combined degeneration of the spinal cord, or as neuropathy, but is often asymptomatic in older people. The diagnosis and indications for treatment are clear for individuals with low plasma levels of vitamin B12 in the setting of me...

BACKGROUND More than 2.9 million serum vitamin B12 tests were performed in 2010 in Ontario at a cost of $40 million. Vitamin B12 deficiency has been associated with a few neurocognitive disorders. OBJECTIVE To determine the clinical utility of B12 testing in patients with suspected dementia or cognitive decline. METHODS Three questions were addressed: Is there an association between vitamin...