Human Nutrition Research Centre, Population Health Sciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
Institute for Global Nutrition, Department of Nutrition, University of California, Davis, CA, USA.
J Nutr. 2021 May 11;151(5):1341-1346. doi: 10.1093/jn/nxaa446.
The retinol isotope dilution (RID) method has been used to evaluate vitamin A (VA) status in healthy adults and children in low- and middle-income countries (LMIC) and to assess the efficacy of various VA interventions.
The study was designed to examine whether dried serum spots (DSS) can be applied to RID when conducting VA total body store (TBS) assessments in community settings.
Four days after an oral dose of 0.4 mg [13C10]retinyl acetate was administered to Filipino children (12-18 mo), a single blood draw was divided to isolate both serum and plasma. Serum (40 μL) was spotted and dried on Whatman 903 cards and shipped at ambient temperature whereas liquid plasma (LP) was frozen at -80°C and shipped on dry ice. The VA tracer to tracee ratio from DSS and LP was quantified by LC-MS/MS. Comparisons between DSS and LP paired samples (n = 72) were made for [13C10]retinol specific activity (SAp) by Pearson's correlation and for VA TBS by Bland-Altman analysis.
The sum of 3 coextracted DSS were required to consistently detect [13C10]retinol above the LC-MS/MS limit of quantitation (LOQ). [13C10]retinol SAp from DSS was highly correlated with SAp from LP (r = 0.945; P < 0.01). A comparison of methods for TBS determination using Bland-Altman analysis indicated agreement with an intraindividual difference of 24.7 μmol (4.6%). Mean total liver reserve (TLR) values from DSS and LP were 1.7 μmol/g (± 0.6 SD) and 1.6 μmol/g (± 0.6 SD), respectively.
VA TBS can be determined from DSS thereby reducing the logistics and cost of maintaining a cold chain by shipping samples at ambient temperature and, thus, making the RID technique more feasible in LMIC community settings. This trial was registered at https://clinicaltrials.gov as NCT03030339.
视黄醇同位素稀释（RID）法已被用于评估低收入和中等收入国家（LMIC）中健康成年人和儿童的维生素 A（VA）状态，并评估各种 VA 干预措施的效果。
本研究旨在探讨在社区环境中进行 VA 总体储存（TBS）评估时，能否将干血清斑（DSS）应用于 RID。
在菲律宾儿童（12-18 个月）口服 0.4mg [13C10]视黄基醋酸盐 4 天后，单次采血分离血清和血浆。将 40 μL 血清点样并干燥于 Whatman 903 卡上，在环境温度下运输，而液体血浆（LP）则在-80°C 下冷冻并在干冰上运输。通过 LC-MS/MS 定量 DSS 和 LP 中 VA 示踪剂与示踪物的比值。对 72 对 DSS 和 LP 配对样本的[13C10]视黄醇比活性（SAp）进行 Pearson 相关分析，对 VA TBS 进行 Bland-Altman 分析。
需要 3 个共提取的 DSS 总和才能一致地检测到 LC-MS/MS 定量下限以上的[13C10]视黄醇。DSS 中的[13C10]视黄醇 SAp 与 LP 中的 SAp 高度相关（r=0.945；P <0.01）。Bland-Altman 分析用于 TBS 测定方法的比较表明，个体内差异为 24.7 μmol（4.6%）。DSS 和 LP 中平均总肝储备（TLR）值分别为 1.7 μmol/g（±0.6 SD）和 1.6 μmol/g（±0.6 SD）。
可以从 DSS 中确定 VA TBS，从而减少通过在环境温度下运输样本来维持冷链的物流和成本，从而使 RID 技术在 LMIC 社区环境中更可行。该试验在 https://clinicaltrials.gov 上注册为 NCT03030339。
