Biochemical indicators of B vitamin status in the US population after folic acid fortification: results from the National Health and Nutrition Examination Survey 1999-2000
Biochemical indicators of B vitamin status in the US population after folic acid fortification: results from the National Health and Nutrition Examination Survey 1999-2000
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DOI：
10.1093/ajcn/82.2.442
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发表时间：
2005-08-01
影响因子：
7.1
通讯作者：
Sampson, EJ
中科院分区：
文献类型：
--
作者：
Pfeiffer, CM;Caudill, SP;Sampson, EJ
背景：美国于1998年引入了谷物产品的强制性叶酸强化，以降低妇女生育神经管缺陷儿童的风险。目的：目的：确定强化叶酸对美国人群血清和红细胞叶酸、血清维生素B-12、血浆总同型半胱氨酸(THcy)和甲基丙二酸(MMA)浓度的影响。设计：采自1999-2000年全国健康与营养调查(NHANES)中约7300名具有代表性的老年人的血液样本，并对这些维生素B状况指标进行分析。结果：参考范围(第5~95百分位数)：血清叶酸为13.1~74.3nmol/L，红细胞叶酸为347~1167nmol/L，血清维生素B-12为179~738pmol/L。对于血浆总同型半胱氨酸和MMA，血清维生素B-12水平正常的受试者参考范围分别为3.2-10.7mU/L和60-210nmol/L。低血清叶酸浓度(6.8nmol/L)的患病率从强化前的16%下降到强化后的0.5%。在老年人中，高血清叶酸浓度(>；45.3nmol/L)的患病率从强化前的7%上升到强化后的38%；3%的人血清维生素B-12浓度略低(<；148pmol/L)，7%的人血浆MMA浓度升高(>；370nmol/L)。78%的美国人血浆tHcy浓度为9 mU/L。结论：美国人中的每一个群体似乎都受益于叶酸强化。继续监测美国人群中的B族维生素浓度是必要的。
Background: Mandatory folic acid fortification of cereal-grain products was introduced in the United States in 1998 to decrease the risk that women will have children with neural tube defects.Objective: The objective was to determine the effect of folic acid fortification on concentrations of serum and red blood cell (RBC) folate, serum vitamin B-12, and plasma total homocysteine (tHcy) and methylmalonic acid (MMA) in the US population.Design: Blood was collected from a nationally representative sample of approximate to 7300 participants aged >= 3 y in the National Health and Nutrition Examination Survey (NHANES) during 1999-2000 and was analyzed for these B vitamin-status indicators. The results were compared with findings from the prefortification survey NHANES III (1988-1994).Results: The reference ranges (5th-95th percentiles) were 13.1-74.3 nmol/L for serum folate, 347-1167 nmol/L for RBC folate, and 179-738 pmol/L for serum vitamin B-12. For plasma tHcy and MMA, the reference ranges for serum vitamin B-12-replete participants with normal serum creatinine concentrations were 3.2-10.7 mu mol/L and 60-210 nmol/L, respectively. The prevalence of low serum folate concentrations (< 6.8 nmol/L) decreased from 16% before to 0.5% after fortification. In elderly persons, the prevalence of high serum folate concentrations (> 45.3 nmol/L) increased from 7% before to 38% after fortification; 3% had marginally low serum vitamin B-12 concentrations (< 148 pmol/L) and 7% had elevated plasma MMA concentrations (> 370 nmol/L). Seventy-eight percent of the US population had plasma tHcy concentrations < 9 mu mol/L.Conclusions: Every segment of the US population appears to benefit from folic acid fortification. Continued monitoring of B vitamin concentrations in the US population is warranted.