Identification of vitamin B12 deficiency in vegetarian Indians
Identification of vitamin B12 deficiency in vegetarian Indians
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识别印度素食者维生素 B12 缺乏症
DOI：
10.1017/s0007114518000090
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发表时间：
2018-03-28
影响因子：
3.6
通讯作者：
Bhide, Vijayshri
中科院分区：
文献类型：
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作者：
Naik, Sadanand;Mahalle, Namita;Bhide, Vijayshri
素食者亚临床维生素B-12缺乏症的发生率很高。血清总维生素B-12浓度本身并不能可靠地反映维生素B-12的状态。全转钴胺素（holo-TC） II是一种生物活性的B-12成分，促进细胞对B-12的特异性吸收，循环浓度反映了B-12的摄入量，而总同型半胱氨酸（tHcy）表明代谢能力。在这项研究中，我们探讨了循环holo-TC、B-12、叶酸和同型半胱氨酸在有b12缺乏症风险的素食者中的诊断价值。在119名年轻健康的素食毕业生中测量了与b12相关的生物标志物。没有人叶酸缺乏。根据报告的定义，其中一半缺乏B-12；70%的男性和50%的女性血浆holo-TC浓度低；92%的男性和一半的女性患有高同型半胱氨酸血症。没有人有b12缺乏症的临床症状。以holo-TC（0.77和0.784）和同型半胱氨酸（0.924和0.928）为变量，B-12浓度为100和150 pmol/l时，受试者工作特征曲线分析显示AUC相似。截断值为100 pmol/l时，holo-TC的灵敏度为77.78%，特异度为71.05%，预测值为19.6 pmol/l；同型半胱氨酸的灵敏度为82.72%，特异度为89.7%，预测值为21.7 mu mol/l。B-12、holo-TC和tHcy的结合提高了这些临界值的诊断准确性，我们建议年轻的印度素食者血浆B-12和holo-TC的临界值分别为100 pmol/l和19.6 pmol/l，同型半胱氨酸的临界值为17.6（女性）和27 mu mol/l（男性），以确定B-12缺乏症。
The prevalence of a sub-clinical vitamin B-12 deficiency in the vegetarians is high. Total serum vitamin B-12 concentration alone does not reliably reflect vitamin B-12 status. Holotranscobalamin (holo-TC) II is a bioactive B-12 fraction promoting specific uptake of B-12 by cells and the circulating concentration reflects the intake of B-12, whereas total homocysteine (tHcy) indicates the metabolic ability. In this study, we investigated the diagnostic value of circulating holo-TC, B-12, folate and homocysteine in vegetarians who were at risk of B-12 deficiency. B-12-related biomarkers were measured in 119 young, healthy graduate vegetarians. None was folate deficient. As per reported definition, half were B-12 deficient; 70 % of males and 50 % of females had low plasma holo-TC concentrations; and 92 % of males and half of females had hyperhomocysteinaemia. None had any clinical signs of B-12 deficiency. Receiver operating characteristic curve analysis demonstrated similar AUC at the B-12 concentration of 100 and 150 pmol/l when holo-TC (0.77 and 0.784) and homocysteine (0.924 and 0.928) were used as variables. Cut-off value of 100 pmol/l resulted in the highest sensitivity of 77.78 % and specificity of 71.05 % with a predictive value of 19.6 pmol/l for holo-TC and a sensitivity of 82.72 % and specificity of 89.7 % with a predictive value of 21.7 mu mol/l for homocysteine. The combination of B-12, holo-TC and tHcy improves the diagnostic accuracy at these cut-offs, and we suggest that for the young Indian vegetarians the cut-off for plasma B-12 and holotrancobalamin is 100 pmol/l and 19.6 pmol/l, respectively, and for homocysteine it is 17.6 (females) and 27 mu mol/l (males) for identifying B-12 deficiency.