Schwettmann Lutz, Berbu Siw
Clin Lab. 2015;61(8):1095-100. doi: 10.7754/clin.lab.2015.150112.
Deficiencies of folate and vitamin B12 lead to an elevated serum concentration of homocysteine which has been associated with many diseases including cardiovascular disease. Laboratory algorithms often include initial testing of serum folate and vitamin B12. Reference intervals for these vitamins can vary significantly among populations for which dietary intakes may be different. The aim of this study was to establish reference intervals in a Norwegian population and to assess the folate and vitamin B12 status related to reference intervals.
Blood samples were taken from 144 healthy volunteers aged 18 - 65 years. A questionnaire provided data of medication, medical history, vitamin supplementation, alcohol consumption, and use of oral contraceptives and others. Serum folate and vitamin B12 concentrations were measured on the Abbott Architect i2000. Reference values were calculated using the bootstrap method. Results of serum folate, vitamin B12, and homocysteine from 1190 individuals from regional primary health care centers were evaluated related to reference values and the proportion of individuals with deficiency was estimated.
Mean serum concentrations of folate and vitamin B12 were 11.9 nmol/L and 328 pmol/L, respectively. Men were found to have statistically significant higher vitamin B12 concentrations than women. 95%-reference intervals were calculated to 5.2 - 29.2 nmol/L for folate and 133 - 595 pmol/L for vitamin B12. 1.1% of the study population has serum vitamin B12-concentrations < 133 pmol/L and 3.4% has serum folate concentrations < 5.2 nmoI/L.
The serum reference intervals for folate and vitamin B12 for a healthy, not vitamin-supplemented adult population were determined from 144 subjects. The application of these intervals will assist in the evaluation of folate and vitamin status.
叶酸和维生素B12缺乏会导致血清同型半胱氨酸浓度升高，这与包括心血管疾病在内的多种疾病有关。实验室检测方法通常包括对血清叶酸和维生素B12进行初始检测。这些维生素的参考区间在饮食摄入可能不同的人群中可能有显著差异。本研究的目的是建立挪威人群的参考区间，并评估与参考区间相关的叶酸和维生素B12状态。
采集了144名年龄在18至65岁之间的健康志愿者的血样。通过问卷调查获取用药、病史、维生素补充、饮酒、口服避孕药及其他使用情况的数据。使用雅培Architect i2000测定血清叶酸和维生素B12浓度。采用自助法计算参考值。评估了来自地区初级卫生保健中心的1190名个体的血清叶酸、维生素B12和同型半胱氨酸结果与参考值的关系，并估计了缺乏个体的比例。
叶酸和维生素B12的平均血清浓度分别为11.9 nmol/L和328 pmol/L。发现男性的维生素B12浓度在统计学上显著高于女性。叶酸的95%参考区间计算为5.2至29.2 nmol/L，维生素B12为133至595 pmol/L。1.1%的研究人群血清维生素B12浓度<133 pmol/L，3.4%的人群血清叶酸浓度<5.2 nmol/L。
从144名受试者中确定了健康、未补充维生素的成年人群的叶酸和维生素B12血清参考区间。应用这些区间将有助于评估叶酸和维生素状态。
