Unmetabolized serum folic acid and its relation to folic acid intake from diet and supplements in a nationally representative sample of adults aged ≥60 y in the United States
Unmetabolized serum folic acid and its relation to folic acid intake from diet and supplements in a nationally representative sample of adults aged ≥60 y in the United States
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DOI：
10.3945/ajcn.2010.29499
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发表时间：
2010-08-01
影响因子：
7.1
通讯作者：
Picciano, Mary Frances
中科院分区：
文献类型：
--
作者：
Bailey, Regan L.;Mills, James L.;Picciano, Mary Frances
背景：在成人中已检测到非代谢血清叶酸(UMFA)。先前的研究表明，高叶酸摄入量可能与癌症风险有关。目的：目的：研究美国老年人群中UMFA浓度与膳食和补充叶酸及状态生物标志物之间的关系；设计：利用2001年至2002年全国健康与营养调查(NHANE2001-2002)中具有全国代表性的横断面调查(n=1121)的数据对过剩血清进行分析。结果：38%的人群检出UMFA，平均浓度为4.4+/-0.6nmol/L(中位数：1.2+/-0.2nmol/L)。服用UMFA(UMFA+)的人群中补充叶酸的比例明显高于不服用UMFA的人群(60%比41%)。添加UMFA的男性和女性的补充量和(食物+补充剂)叶酸总摄入量也高于没有使用UMFA的同龄人。40%的UMFA+组处于叶酸总摄入量的最高四分位数，但总叶酸摄入量仅与UMFA浓度中等相关(r(2)=0.07)。血清叶酸浓度在UMFA+组显著升高，并可预测UMFA浓度(r(2)=0.15)。UMFA+组血清5-甲基四氢叶酸和维生素B-12浓度高于UMFA+组，而红细胞叶酸、血清同型半胱氨酸或甲基丙二酸浓度在UMFA+组之间无差异。结论：美国大约40%的老年人UMFA在禁食后持续存在，UMFA的存在不能仅用叶酸摄入量来解释。鉴于过量叶酸暴露可能与癌症风险有关，对UMFA的监测可能是有必要的。AM J Clin Nutr 2010；92：383-9。
Background: Unmetabolized serum folic acid (UMFA) has been detected in adults. Previous research indicates that high folic acid intakes may be associated with risk of cancer.Objective: The objective was to examine UMFA concentrations in relation to dietary and supplemental folate and status biomarkers in the US population aged >= 60 y.Design: Surplus sera were analyzed with the use of data from the National Health and Nutrition Examination Survey (NHANES) 2001-2002, a cross-sectional, nationally representative survey (n = 1121).Results: UMFA was detected in 38% of the population, with a mean concentration of 4.4 +/- 0.6 nmol/L (median: 1.2 +/- 0.2 nmol/L). The group with UMFA (UMFA+) had a significantly higher proportion of folic acid supplement users than did the group without UMFA (60% compared with 41%). UMFA+ men and women also had higher supplemental and total (food + supplements) folic acid intakes than did their counterparts without UMFA. Forty percent of the UMFA+ group was in the highest quartile of total folic acid intake, but total folic acid intake was only moderately related to UMFA concentrations (r(2) = 0.07). Serum folate concentrations were significantly higher in the UMFA+ group and were predictive of UMFA concentrations (r(2) = 0.15). Serum 5-methyltetrahydrofolate and vitamin B-12 concentrations were higher in the UMFA+ group, whereas there was no difference between the 2 UMFA groups in red blood cell folate, serum homocysteine, or methylmalonic acid concentrations.Conclusions: Approximately 40% of older adults in the United States have UMFA that persists after a fast, and the presence of UMFA is not easily explained in NHANES by folic acid intakes alone. Given the possibility that excessive folic acid exposure may relate to cancer risk, monitoring of UMFA may be warranted. Am J Clin Nutr 2010; 92: 383-9.