National Center on Birth Defects and Developmental Disabilities, CDC, Atlanta, GA, USA.
Epidemic Intelligence Service Program, CDC, Atlanta, GA, USA.
Am J Clin Nutr. 2022 Jul 6;116(1):74-85. doi: 10.1093/ajcn/nqac065.
Cognitive health is a public health concern among older adults. Dietary supplement (SUP) use is common and concerns have been raised about high folic acid intake among those with vitamin B-12 deficiency and exacerbation of poor cognitive performance (PCP).
We evaluated SUP use, usual folic acid intake, and blood folate and vitamin B-12 concentrations in relation to cognitive performance.
We used NHANES 2011-2014 data on adults aged ≥60 y (n = 2867) and estimated total usual folic acid intake from diet and supplements, vitamin B-12 intake from SUPs, blood folates, vitamin B-12 concentrations, vitamin B-12 insufficiency (≤258 pmol/L), high folate (serum folate ≥59 nmol/L or RBC folate ≥1609 nmol/L), and PCP (<34 on the Digit Symbol Substitution Test). We assessed folate distributions adjusted for multiple variables, including renal function.
Compared with persons without PCP, adults with PCP were less likely to use supplements containing folic acid (mean ± SEE: 34.4% ± 2.4%) or vitamin B-12 (mean ± SEE: 47.5% ± 1.6%). Among vitamin B-12-insufficient adults, 18.0% ± 1.6% (mean ± SEE) reported taking a vitamin B-12 supplement. Among participants with high folate and insufficient vitamin B-12 concentrations, 34.3% ± 11.5% (mean ± SEE) reported taking vitamin B-12-containing supplements. Persons with high folate and normal vitamin B-12 concentrations had lower odds of PCP [aOR (adjusted odds ratio): 0.61; 95% CI: 0.45, 0.83] than persons with normal folate and vitamin B-12. Persons with high folate and normal methylmalonic acid (MMA) had lower odds of PCP (OR: 0.56; 95% CI: 0.40, 0.78) than those with normal folate and MMA concentrations. After adjustment for renal function, elevated risk of PCP was attenuated among persons with high folate and MMA. Concurrent high folate and insufficient vitamin B-12 concentrations were not associated with PCP.
Differential associations between vitamin B-12 and MMA highlight the need to consider renal function in studies of high folate and low vitamin B-12 status. Consumption of vitamin B-12 supplements concurrent with low vitamin B-12 status may indicate vitamin B-12 malabsorption.
认知健康是老年人的公共健康关注点。膳食补充剂（SUP）的使用很普遍，人们担心维生素 B-12 缺乏症患者的叶酸摄入量过高会导致认知表现恶化（PCP）。
我们评估了 SUP 的使用、通常的叶酸摄入量以及与认知表现相关的血液叶酸和维生素 B-12 浓度。
我们使用了 2011-2014 年 NHANES 数据，纳入年龄≥60 岁的成年人（n=2867），并根据饮食和补充剂估计了总叶酸摄入量，根据 SUP 估计了维生素 B-12 摄入量，还检测了血液叶酸、维生素 B-12 浓度、维生素 B-12 不足（≤258 pmol/L）、高叶酸（血清叶酸≥59 nmol/L 或 RBC 叶酸≥1609 nmol/L）和 PCP（数字符号替代测试<34）。我们评估了叶酸分布，分布调整了多种变量，包括肾功能。
与没有 PCP 的成年人相比，有 PCP 的成年人更不可能使用含有叶酸（平均±标准误差：34.4%±2.4%）或维生素 B-12（平均±标准误差：47.5%±1.6%）的补充剂。在维生素 B-12 不足的成年人中，有 18.0%±1.6%（平均±标准误差）报告服用了维生素 B-12 补充剂。在高叶酸和维生素 B-12 浓度不足的参与者中，有 34.3%±11.5%（平均±标准误差）报告服用了含有维生素 B-12 的补充剂。高叶酸和正常维生素 B-12 浓度的人患 PCP 的可能性较低[调整后的比值比（aOR）：0.61；95%CI：0.45，0.83]，而叶酸和维生素 B-12 正常的人患 PCP 的可能性较低。高叶酸和正常甲基丙二酸（MMA）的人患 PCP 的可能性较低（OR：0.56；95%CI：0.40，0.78），而叶酸和 MMA 浓度正常的人则较低。在调整肾功能后，高叶酸和 MMA 的人患 PCP 的风险降低。高叶酸和维生素 B-12 不足同时存在与 PCP 无关。
维生素 B-12 和 MMA 之间的差异关联突出表明，在研究高叶酸和低维生素 B-12 状态时，需要考虑肾功能。同时存在低维生素 B-12 状态和维生素 B-12 补充剂的消耗可能表明维生素 B-12 吸收不良。
