Department of Chemical Pathology, University of Nigeria Teaching Hospital, Ituku/ozalla, Enugu, Nigeria.
Department of Morbid Anatomy, University of Nigeria Teaching Hospital, Enugu, Nigeria.
Afr Health Sci. 2022 Dec;22(4):220-228. doi: 10.4314/ahs.v22i4.27.
Elderly people have increased risk factors for low serum vitamin D levels, which is worsened among the black race. Therefore, elderly Africans constitute a reference population for vitamin D study.
The aim of this study was to establish the reference interval of serum 25-hydroxyvitamin D (25(OH)D) among an African elderly population.
This was a cross-sectional study of rural community dwellers in Enugu, south-eastern Nigeria aged 50 years and above, that satisfied the criteria of the reference population. Ethical approval and informed consent were obtained. Venous blood was collected from reference individuals and serum 25(OH)D was determined by enzyme-linked immunosorbent assay. Data were analysed using a non-parametric, bootstrap method to obtain the central 95% reference limits and 90% confidence intervals of the lower and upper limits of the reference interval respectively.
One hundred and twenty-four (62 males and 62 females) participants were recruited. The median (25th -75th percentile) of serum 25(OH)D was 56 (35 - 71) ng/ml. The 2.5th percentile defined the lower reference limit and it was 21 ng/ml with 90% confidence interval (20 - 23) ng/ml; while the 97.5th percentile defined the upper reference limit and it was 93 ng/ml with 90% confidence interval (90 - 98) ng/ml.
The reference interval for serum 25(OH)D for the selected African elderly population in Enugu, Nigeria was determined to be 21 to 93 ng/ml.
老年人的血清维生素 D 水平较低的风险因素增加，而黑种人则更为严重。因此，老年非洲人构成了维生素 D 研究的参考人群。
本研究旨在确定尼日利亚东南部埃努古农村社区 50 岁及以上老年人群的血清 25-羟维生素 D（25(OH)D）参考区间。
这是一项横断面研究，研究对象为满足参考人群标准的尼日利亚东南部埃努古农村社区的 50 岁及以上的居民。本研究获得了伦理批准和知情同意。从参考个体中采集静脉血，并通过酶联免疫吸附试验测定血清 25(OH)D。使用非参数、自举法分析数据，以获得中央 95%参考限值和 90%置信区间的下、上限参考区间的下、上限。
共招募了 124 名（62 名男性和 62 名女性）参与者。血清 25(OH)D 的中位数（25 百分位数-75 百分位数）为 56（35-71）ng/ml。第 2.5 个百分位数定义了下限参考值，为 21ng/ml，90%置信区间为（20-23）ng/ml；第 97.5 个百分位数定义了上限参考值，为 93ng/ml，90%置信区间为（90-98）ng/ml。
尼日利亚埃努古选定的非洲老年人群的血清 25(OH)D 参考区间为 21-93ng/ml。
