Department of Metabolism and Nutrition, Institute of Food Science, Technology and Nutrition (ICTAN-CSIC), 28040, Madrid, Spain.
Unit Service of Analytical Techniques, Instrumentation and Microbiology, Institute of Food Science, Technology and Nutrition (ICTAN-CSIC), 28040, Madrid, Spain.
Plant Foods Hum Nutr. 2018 Sep;73(3):166-171. doi: 10.1007/s11130-018-0677-y.
Cobalamin deficiency represents a health issue for vegetarians, especially vegans, if supplements are not consumed. Vitamin B12 serum levels, traditionally used to assess the vitamin B12 status, can be normal under functional deficiency conditions. In this regard, methylmalonic acid (MMA) has proven to be a more specific marker to detect subclinical vitamin B12 deficiency. In this study, we present for the first time the cobalamin status of Spanish vegetarians using both vitamin B12 and MMA markers, and the effects of the plant-based diet and the intake of vitamin B12 supplements. Healthy adults were recruited (n = 103, 52% vegans). Dietary preferences and use of supplements were assessed by questionnaires and serum samples were collected and stored. Vitamin B12 was measured by chemiluminiscence and MMA by liquid chromatography tandem mass spectrometry (LC-MS/MS) using solid phase extraction for sample preparation. Obtained values, median (IQR), were: vitamin B12, 278.9 (160.2) pmol/l and MMA, 140.2 (78.9) nmol/l. No significant differences between lacto-ovo vegetarians and vegans were observed. Considering these two markers, 10% of the participants were mild vitamin B12 deficient. Supplementation (75% of the participants) was associated with higher vitamin B12 (p < 0.001) and lower MMA (p = 0.012). In conclusion, Spanish vegetarians have low risk of vitamin B12 deficiency due to vitamin B12 supplementation and the MMA determination is useful to detect mild deficiency.
钴胺素缺乏代表了素食者（尤其是严格素食者）的健康问题，如果不补充营养剂的话。传统上用于评估维生素 B12 状况的血清维生素 B12 水平在功能性缺乏的情况下可能是正常的。在这方面，甲基丙二酸（MMA）已被证明是一种更特异的标志物，可用于检测亚临床维生素 B12 缺乏。在这项研究中，我们首次使用维生素 B12 和 MMA 标志物来呈现西班牙素食者的钴胺素状况，并探讨了植物性饮食和维生素 B12 补充剂的摄入对其的影响。我们招募了健康的成年人（n=103，52%为严格素食者）。通过问卷评估饮食偏好和营养补充剂的使用情况，并采集和储存血清样本。采用化学发光法测定维生素 B12，采用液相色谱串联质谱法（LC-MS/MS）结合固相萃取法测定 MMA。获得的数值（中位数[IQR]）为：维生素 B12 为 278.9（160.2）pmol/L，MMA 为 140.2（78.9）nmol/L。乳蛋素食者和严格素食者之间未观察到显著差异。考虑到这两个标志物，10%的参与者存在轻度维生素 B12 缺乏。补充（75%的参与者）与较高的维生素 B12（p<0.001）和较低的 MMA（p=0.012）相关。综上所述，由于维生素 B12 补充和 MMA 测定，西班牙素食者发生维生素 B12 缺乏的风险较低，且 MMA 测定有助于发现轻度缺乏。
