Concentrations of unmetabolized folic acid and primary folate forms in plasma after folic acid treatment in older adults

Obeid, Rima; Kirsch, Sarah; Kasoha, Mariz; Eckert, Rudolf; Herrmann, Wolfgang

doi:10.1016/j.metabol.2010.06.020

Cited by 39 publications

(43 citation statements)

References 35 publications

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“…In line with our study, the tHcylowering effect was highest in individuals with higher tHcy at baseline [26]. 5-MethylTHF in serum and red blood cells [23,33] was increased after 500 μg FA in our study to concentrations that are similar to the one found under fortification [30,34] or long-term supplementation of 400 μg FA for 40 weeks [35]. The results showed that baseline folate and the increased folate levels do not completely explain the metabolic response (e.g.…”

Section: Discussionsupporting

confidence: 78%

One year B-vitamins increases serum and whole blood folate forms and lowers plasma homocysteine in older Germans

Kirsch

Herrmann

Kruse

et al. 2015

Clinical Chemistry and Laboratory Medicine (CCLM)

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Section: Discussionsupporting

confidence: 78%

One year B-vitamins increases serum and whole blood folate forms and lowers plasma homocysteine in older Germans

Kirsch

Herrmann

Kruse

et al. 2015

Clinical Chemistry and Laboratory Medicine (CCLM)

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“…As discussed in earlier sections, unmetabolized folic acid in serum or plasma may be considered as a biomarker of exposure, status, function, and/or effect. The appearance and quantity of unmetabolized folic acid in circulation have been associated with folic acid exposure via fortified foods, dietary supplements, and a combination of both (7,252,253). Greater concentrations of unmetabolized folic acid are associated with higher serum folate concentrations (7,254), suggesting that the amount of folic acid in blood is related to whole-body folate status.…”

Section: Other Biomarkers-general Descriptionsmentioning

confidence: 99%

Biomarkers of Nutrition for Development—Folate Review

Lynch¹,

Pfeiffer

Georgieff

et al. 2015

The Journal of Nutrition

654

412

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The Biomarkers of Nutrition for Development (BOND) project is designed to provide evidence-based advice to anyone with an interest in the role of nutrition in health. Specifically, the BOND program provides state-of-the-art information and service with regard to selection, use, and interpretation of biomarkers of nutrient exposure, status, function, and effect. To accomplish this objective, expert panels are recruited to evaluate the literature and to draft comprehensive reports on the current state of the art with regard to specific nutrient biology and available biomarkers for assessing nutrients in body tissues at the individual and population level. Phase I of the BOND project includes the evaluation of biomarkers for 6 nutrients: iodine, iron, zinc, folate, vitamin A, and vitamin B-12. This review represents the second in the series of reviews and covers all relevant aspects of folate biology and biomarkers. The article is organized to provide the reader with a full appreciation of folate's history as a public health issue, its biology, and an overview of available biomarkers (serum folate, RBC folate, and plasma homocysteine concentrations) and their interpretation across a range of clinical and population-based uses. The article also includes a list of priority research needs for advancing the area of folate biomarkers related to nutritional health status and development.

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“…Fortification with FA increased folate status in the whole population, but this effect seems not to be sufficient in the target group [4,91]. Moreover, increasing FA intake caused the appearance of unmetabolized FA in the blood [83,113]. Unmetabolized FA was detected in newborns and in 4-day-old formula-fed infants [112].…”

Section: Strategies To Prevent Ntds By Improving Maternal Folate Statusmentioning

confidence: 99%

Is 5-methyltetrahydrofolate an alternative to folic acid for the prevention of neural tube defects?

Obeid

Holzgreve

Pietrzik

2013

Journal of Perinatal Medicine

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Women have higher requirements for folate during pregnancy. An optimal folate status must be achieved before conception and in the first trimester when the neural tube closes. Low maternal folate status is causally related to neural tube defects (NTDs). Many NTDs can be prevented by increasing maternal folate intake in the preconceptional period. Dietary folate is protective, but recommending increasing folate intake is ineffective on a population level particularly during periods of high demands. This is because the recommendations are often not followed or because the bioavailability of food folate is variable. Supplemental folate [folic acid (FA) or 5-methyltetrahydrofolate (5-methylTHF)] can effectively increase folate concentrations to the level that is considered to be protective. FA is a synthetic compound that has no biological functions unless it is reduced to dihydrofolate and tetrahydrofolate. Unmetabolized FA appears in the circulation at doses of > 200 μg. Individuals show wide variations in their ability to reduce FA. Carriers of certain polymorphisms in genes related to folate metabolism or absorption can better benefit from 5-methylTHF instead of FA. 5-MethylTHF [also known as (6S)-5-methylTHF] is the predominant natural form that is readily available for transport and metabolism. In contrast to FA, 5-methylTHF has no tolerable upper intake level and does not mask vitamin B 12 deficiency. Supplementation of the natural form, 5-methylTHF, is a better alternative to supplementation of FA, especially in countries not applying a fortification program. Supplemental 5-methylTHF can effectively improve folate biomarkers in young women in early pregnancy in order to prevent NTDs.

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Concentrations of unmetabolized folic acid and primary folate forms in plasma after folic acid treatment in older adults

Cited by 39 publications

References 35 publications

One year B-vitamins increases serum and whole blood folate forms and lowers plasma homocysteine in older Germans

One year B-vitamins increases serum and whole blood folate forms and lowers plasma homocysteine in older Germans

Biomarkers of Nutrition for Development—Folate Review

Is 5-methyltetrahydrofolate an alternative to folic acid for the prevention of neural tube defects?

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