Impact of body composition on vitamin D requirements in healthy adults with vitamin D deficiency

作者：Dexing Dai, Yali Ling, Feng Xu, Haibo Li, Rui Wang, Yingying Gu, Xuedi Xia, An Xiong, Ruoman Sun, Lei Qiu, Ya Ding, Yu YiXin, Xueyang Cai, Zhongjian Xie · 发表于：Frontiers in Endocrinology · 年份：2025 · DOI：10.3389/fendo.2025.1421663 · 被引用次数：7 · 研究领域：Vitamin D Research Studies、HIV-related health complications and treatments、Body Composition Measurement Techniques

Background Previous studies have shown that individuals with high body mass index typically require high doses of vitamin D supplementation to correct vitamin D deficiency. However, it is unclear which specific body composition is the determining factor affecting the bioavailability of vitamin D after supplementation. The aim of this study was to determine which body components affect the bioavailability of vitamin D. Methods In order to ensure the compliance of the study subjects and avoid the impact of sunlight on vitamin D 3 levels, the subjects received multiple intramuscular (i.m.) injections of vitamin D 2 until their serum levels of 25-hydroxyvitamin D [25(OH)D] were above 30 ng/mL. All subjects received two i.m. injections of 600,000 IU vitamin D 2 , and dose adjustments were made every 6 weeks based on whether serum 25(OH)D levels were sufficient. The levels of serum 25(OH)D 2 and 25(OH)D 3 were determined by liquid chromatography tandem mass spectrometry. The body composition was measured using dual-energy X-ray absorptiometry and corrected using body fat mass index (FMI). Based on the 100% difference in 25(OH)D levels before and after vitamin D supplementation, the sample size was calculated, and 20 subjects would provide over 95% of the power to show the difference. Results After two dose adjustment, the serum 25(OH)D levels of all subjects were above 30 ng/mL. The subjects were divided into ≤ 1,200,000 IU vitamin D 2 ( n =10) and ≥ 2,400,000 IU vitamin D 2 ( n =1...