Human Nutrition Department, College of Health Sciences, Qatar University, P.O. Box 2713, Doha, Qatar.
Department of Mathematics, San Francisco State University, San Francisco, CA 94132, USA.
Nutrients. 2018 Jan 12;10(1):74. doi: 10.3390/nu10010074.
Serum methylmalonic acid (MMA) is elevated in vitamin B-12 deficiency and in kidney dysfunction. Population reference values for serum MMA concentrations in post-folic acid fortification period are lacking. Aims of this study were to report the population reference values for serum MMA and to evaluate the relation between serum MMA and sex, age, race-ethnicity, kidney dysfunction and vitamin B-12. We used data from three National Health and Nutrition Examination Surveys, 1999-2000, 2001-2002 and 2003-2004 conducted after folic acid fortification commenced ( = 18,569). Geometric mean MMA was ≈22.3% higher in non-Hispanic white compared to non-Hispanic black (141.2 vs. 115.5 nmol/L) and was ≈62.7% higher in >70 years old persons compared to 21-30 years old persons (196.9 vs. 121.0 nmol/L). Median serum MMA was ≈28.5% higher in the 1st the quartile of serum vitamin B-12 than in the 4th quartile of serum vitamin B-12 and was ≈35.8% higher in the 4th quartile of serum creatinine than in the 1st quartile of serum creatinine. Multivariate-adjusted serum MMA concentration was significantly associated with race-ethnicity ( < 0.001) and age ( < 0.001) but not with sex ( = 0.057). In this large US population based study, serum MMA concentrations presented here reflect the post-folic acid fortification scenario. Serum MMA concentrations begin to rise at the age of 18-20 years and continue to rise afterwards. Age-related increase in serum MMA concentration is likely to be due to a concomitant decline in kidney function and vitamin B-12 status.
血清甲基丙二酸（MMA）在维生素 B12 缺乏和肾功能障碍时升高。叶酸强化后时期血清 MMA 浓度的人群参考值尚缺乏。本研究的目的是报告血清 MMA 的人群参考值，并评估血清 MMA 与性别、年龄、种族、肾功能障碍和维生素 B12 之间的关系。我们使用了 1999-2000 年、2001-2002 年和 2003-2004 年三项在叶酸强化后进行的国家健康和营养调查的数据（n=18569）。与非西班牙裔黑人相比，非西班牙裔白人的几何均数 MMA 约高 22.3%（141.2 与 115.5 nmol/L），与 21-30 岁相比，>70 岁的人 MMA 约高 62.7%（196.9 与 121.0 nmol/L）。与维生素 B12 血清第 4 四分位数相比，维生素 B12 血清第 1 四分位数的中位数血清 MMA 约高 28.5%，与血清肌酐第 1 四分位数相比，血清肌酐第 4 四分位数的中位数血清 MMA 约高 35.8%。校正了多种因素的血清 MMA 浓度与种族（<0.001）和年龄（<0.001）显著相关，但与性别无关（=0.057）。在这项大型美国人群研究中，这里呈现的血清 MMA 浓度反映了叶酸强化后的情况。血清 MMA 浓度在 18-20 岁时开始上升，此后继续上升。血清 MMA 浓度与年龄相关的增加可能是由于肾功能和维生素 B12 状态同时下降所致。
