To the Editor: In the December 11, 2007, issue of PNAS, Selhub et al. (1) suggest that the association between elevated serum folate and methylmalonic acid (MMA) concentrations in vitamin B12 deficiency resulted from disruption of MMA metabolism by folate. An alternative explanation is that the increase in both serum folate and MMA concentrations resulted from the severity of the vitamin B12 de...

BACKGROUND Serum folate concentration is lower in individuals with the methylenetetrahydrofolate reductase (MTHFR) 677TT genotype than in those with the MTHFR 677CC or 677CT genotypes. Since studies considering folate intake are limited, we examined the association between folate intake and serum folate levels, according to the genotype. METHODS The subjects comprised 170 Japanese persons (74...

Folate status is inversely related to the risk of colorectal cancer. Whether conventional blood measurements of folate status accurately reflect folate concentrations in the colorectal mucosa has been a controversial topic. This is an important issue because accurate measures of folate status in the colorectal mucosa are important for ascertaining the risk of colorectal cancer in epidemiologica...

A relationship between Alzheimer's disease (AD) and folate has been reported. Amyloid positron emission tomography (PET) is currently one of the most reliable biomarkers for AD. We investigated the correlation between serum folate levels and amyloid imaging to clarify whether serum folate could be a biomarker for AD. We also examined the usefulness of a combined assessment of serum folate level...

BACKGROUND Lung cancer is a leading cause of cancer-related mortality globally. Folate helps to maintain DNA integrity and to regulate gene expression. Serum folate levels may affect the risk of several cancers, including lung cancer. In this study we evaluated the association between serum folate concentration and variations in genes involved in folate metabolism with lung cancer incidence in ...

BACKGROUND Serum folate levels are commonly ordered for multiple indications in the inpatient and emergency department settings. Since mandatory folic acid fortification in 1998, there has been a decreasing prevalence of folate deficiency in the United States. OBJECTIVE Our objective was to determine the indications, rate of deficiency, charge and cost per deficient result, and change in mana...

The diagnostic value of the serum folate assay has been assessed in 90 patients, each of whom had a macrocytic anaemia and a low serum vitamin B(12) level. Twenty-nine (32%) patients were found to have anaemia due primarily to folate deficiency. The cause of the low serum vitamin B(12) levels is uncertain in the 22 (25%) patients with normal or borderline vitamin B(12) absorption. The effect of...

BACKGROUND Low dietary intake and low serum concentrations of vitamin B6 and/or folate are associated with increased risk of vascular events, possibly because of their association with inflammation, which plays a crucial role in the pathogenesis of cardiovascular diseases. METHODS Using data from 1320 participants in the population-based InCHIANTI study (586 men and 734 women; median age, 69 ...

Background: Alzheimer's disease is the most common form of dementia in the elderly. Serum levels of homocysteine have been related to increased cortical and hippocampal atrophy. We aimed to determine the serum levels of homocysteine, folate, and vitamin B12 in patients with Alzheimer's disease. Methods: Blood levels of homocysteine and its biological determinants, folate, and vitamin B12 were m...

Folate status is inversely related to the risk of colorectal cancer. Whether conventional blood measurements of folate status accurately reflect folate concentrations in the colorectal mucosa has been a controversial topic. This is an important issue because accurate measures of folate status in the colorectal mucosa are important for ascertaining the risk of colorectal cancer in epidemiologica...