A Combined High-Performance Liquid Chromatographic–Microbiological Assay for Serum Folic Acid

Kelly, P.V.; McPartlin, Joseph; Scott, John M.

doi:10.1006/abio.1996.0272

Cited by 55 publications

(41 citation statements)

References 1 publication

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“…Nevertheless, it has been known for some years that oral doses of folic acid in physiologic quantities can saturate this conversion mechanism, resulting in detectable levels of circulating folic acid, and there has been some concern that this oxidized, nonsubstituted form of folate might feasibly be detrimental because it is not a naturally occurring coenzymatic form of the vitamin. Several studies have shown that as little as 200 Ag of oral folic acid may produce the acute appearance of detectable levels of folic acid in the bloodstream (34)(35)(36), and more recently, it has been shown that the daily ingestion of 400 Ag produces a sustained appearance of folic acid in the blood (37). Up to 35% of the U.S. adult population is thought to regularly consume a supplement containing folic acid, most of which contain 400 Ag per pill (38).…”

Section: Discussionmentioning

confidence: 99%

A Temporal Association between Folic Acid Fortification and an Increase in Colorectal Cancer Rates May Be Illuminating Important Biological Principles: A Hypothesis

Mason

Dickstein

Jacques

et al. 2007

Cancer Epidemiology, Biomarkers &Amp; Prevention

396

290

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Nationwide fortification of enriched uncooked cereal grains with folic acid began in the United States and Canada in 1996 and 1997, respectively, and became mandatory in 1998. The rationale was to reduce the number of births complicated by neural tube defects. Concurrently, the United States and Canada experienced abrupt reversals of the downward trend in colorectal cancer (CRC) incidence that the two countries had enjoyed in the preceding decade: absolute rates of CRC began to increase in 1996 (United States) and 1998 (Canada), peaked in 1998 (United States) and 2000 (Canada), and have continued to exceed the pre-1996/1997 trends by 4 to 6 additional cases per 100,000 individuals. In each country, the increase in CRC incidence from the prefortification trend falls significantly outside of the downward linear fit based on nonparametric 95% confidence intervals. The statistically significant increase in rates is also evident when the data for each country are analyzed separately for men and women. Changes in the rate of colorectal endoscopic procedures do not seem to account for this increase in CRC incidence. These observations alone do not prove causality but are consistent with the known effects of folate on existing neoplasms, as shown in both preclinical and clinical studies. We therefore hypothesize that the institution of folic acid fortification may have been wholly or partly responsible for the observed increase in CRC rates in the mid-1990s. Further work is needed to definitively establish the nature of this relationship. In the meantime, deliberations about the institution or enhancement of fortification programs should be undertaken with these considerations in mind. This communication highlights a temporal association between folic acid fortification of enriched cereal grains in the United States and Canada and an increase in the incidence of CRC in these two countries. The possibility that folic acid fortification was causally responsible for this increase in CRC incidence is consistent with the known biological functions of folate and with several preclinical and clinical observations that are briefly reviewed in this article. However, the observations and integration of knowledge presented here merely create a hypothetical foundation on which further research will be required to determine whether true causality exists.

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Section: Discussionmentioning

confidence: 99%

A Temporal Association between Folic Acid Fortification and an Increase in Colorectal Cancer Rates May Be Illuminating Important Biological Principles: A Hypothesis

Mason

Dickstein

Jacques

et al. 2007

Cancer Epidemiology, Biomarkers &Amp; Prevention

396

290

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“…Heparinized plasma was assayed for FAD (18), vitamin B6 (19), and folic acid (20) by HPLC, as well as for the determination of the EGR-activation coefficient (EGR-AC) (21) in red blood cell lysates (22).…”

Section: Methodsmentioning

confidence: 99%

High doses of riboflavin and the elimination of dietary red meat promote the recovery of some motor functions in Parkinson's disease patients

Coimbra

Junqueira

2003

Braz J Med Biol Res

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Abnormal riboflavin status in the absence of a dietary deficiency was detected in 31 consecutive outpatients with Parkinson's disease (PD), while the classical determinants of homocysteine levels (B6, folic acid, and B12) were usually within normal limits. In contrast, only 3 of 10 consecutive outpatients with dementia without previous stroke had abnormal riboflavin status. The data for 12 patients who did not complete 6 months of therapy or did not comply with the proposed treatment paradigm were excluded from analysis. Nineteen PD patients (8 males and 11 females, mean age ± SD = 66.2 ± 8.6 years; 3, 3, 2, 5, and 6 patients in Hoehn and Yahr stages I to V) received riboflavin orally (30 mg every 8 h) plus their usual symptomatic medications and all red meat was eliminated from their diet. After 1 month the riboflavin status of the patients was normalized from 106.4 ± 34.9 to 179.2 ± 23 ng/ml (N = 9). Motor capacity was measured by a modification of the scoring system of Hoehn and Yahr, which reports motor capacity as percent. All 19 patients who completed 6 months of treatment showed improved motor capacity during the first three months and most reached a plateau while 5/19 continued to improve in the 3-to 6-month interval. Their average motor capacity increased from 44 to 71% after 6 months, increasing significantly every month compared with their own pretreatment status (P < 0.001, Wilcoxon signed rank test). Discontinuation of riboflavin for several days did not impair motor capacity and yellowish urine was the only side effect observed. The data show that the proposed treatment improves the clinical condition of PD patients. Riboflavin-sensitive mechanisms involved in PD may include glutathione depletion, cumulative mitochondrial DNA mutations, disturbed mitochondrial protein complexes, and abnormal iron metabolism. More studies are required to identify the mechanisms involved.

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“…Firstly, the levels of 5MeTHF achieved following a 3 mg and 5 mg oral dose of folic acid are ϳ150 and Ϫ200nmol/L respectively [62,88]. Secondly, the scavenging potency of 5MeTHF was ϳ20 fold lower than the scavenging effects of vitamin C [89].…”

Section: Folate As An Antioxidant?mentioning

confidence: 99%

Folate, homocysteine, endothelial function and cardiovascular disease

Moat

Lang

McDowell

et al. 2004

The Journal of Nutritional Biochemistry

211

148

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A Combined High-Performance Liquid Chromatographic–Microbiological Assay for Serum Folic Acid

Cited by 55 publications

References 1 publication

A Temporal Association between Folic Acid Fortification and an Increase in Colorectal Cancer Rates May Be Illuminating Important Biological Principles: A Hypothesis

A Temporal Association between Folic Acid Fortification and an Increase in Colorectal Cancer Rates May Be Illuminating Important Biological Principles: A Hypothesis

High doses of riboflavin and the elimination of dietary red meat promote the recovery of some motor functions in Parkinson's disease patients

Folate, homocysteine, endothelial function and cardiovascular disease

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