Department of Clinical Sciences, Cornell University, Ithaca, New York 14853, USA,
Heartland Assays, Iowa State University Research Park, Ames, Iowa 50010, USA.
J Zoo Wildl Med. 2023 Jul;54(2):219-230. doi: 10.1638/2022-0024.
Vitamin D supplementation may pose a significant health risk in species where levels of deficiency, sufficiency, and toxicity have not been clearly established, and species-specific research on vitamin D supplementation should be performed. This study documented the effect of vitamin D supplementation on serum vitamin D metabolites and other analytes of Ca homeostasis in Asian elephants (). Six adult Asian elephants received PO supplementation with cholecalciferol at 300 IU/kg of body weight (BW) once a week for 24 wk. Serum was analyzed every 4 wk for 25-hydroxyvitamin D/D [25(OH)D]; 24,25-dihydroxyvitamin D/D [24,25(OH)D]; 1,25-dihydroxyvitamin D [1,25(OH)D]; parathyroid hormone (PTH); total Ca; ionized Ca (iCa); P; and Mg. After the supplement was discontinued, serum 25(OH)D/D was measured every 4 wk until levels returned to baseline. At the start of the study, the average serum 25(OH)D was nondetectable (<1.5 ng/ml). With cholecalciferol supplementation, 25(OH)D increased at an average rate of 2.26 ng/ml per month and reached an average concentration of 12.9 ± 3.46 ng/ml at 24 wk. Both 24,25(OH)D and 1,25(OH)D increased over time with supplementation from an average of <1.5 to 12.9 ng/ml and from 9.67 to 36.4 pg/ml, respectively. PTH, iCa, Ca, P, and Mg remained within reported normal ranges throughout supplementation. After the supplement was discontinued, serum 25(OH)D demonstrated a slow decline to baseline, taking an average of 48 wk. Elephants demonstrated significant individual variation in response to supplementation and subsequent return to baseline. Supplementation of Asian elephants with a weekly dose of 300 IU/kg BW cholecalciferol for 24 wk appears to be effective and safe. Additional clinical studies would be necessary to investigate the safety of other routes of administration, dosages, and duration of vitamin D supplementation, as well as associated health benefits.
维生素 D 补充可能对那些尚未明确确定缺乏、充足和毒性水平的物种构成重大健康风险，应针对特定物种进行维生素 D 补充的研究。本研究记录了维生素 D 补充对亚洲象（）血清维生素 D 代谢物和其他钙稳态分析物的影响。六头成年亚洲象每周一次口服胆钙化醇，剂量为 300IU/kg 体重，持续 24 周。每 4 周分析一次血清 25-羟维生素 D/D [25(OH)D]；24,25-二羟维生素 D/D [24,25(OH)D]；1,25-二羟维生素 D [1,25(OH)D]；甲状旁腺激素（PTH）；总钙；离子钙（iCa）；磷；和镁。补充停止后，每 4 周测量一次血清 25(OH)D/D，直到水平恢复到基线。研究开始时，平均血清 25(OH)D 无法检测到（<1.5ng/ml）。在胆钙化醇补充下，25(OH)D 每月以平均 2.26ng/ml 的速度增加，在 24 周时达到平均浓度 12.9±3.46ng/ml。随着补充，24,25(OH)D 和 1,25(OH)D 的水平均随时间升高，分别从平均<1.5ng/ml 升高至 12.9ng/ml，从 9.67pg/ml 升高至 36.4pg/ml。PTH、iCa、Ca、P 和 Mg 在整个补充过程中均保持在报告的正常范围内。补充停止后，血清 25(OH)D 缓慢下降至基线，平均需要 48 周。大象对补充的反应和随后恢复至基线表现出显著的个体差异。每周剂量为 300IU/kg BW 胆钙化醇补充 24 周对亚洲象似乎是有效且安全的。需要进一步的临床研究来调查其他给药途径、剂量和维生素 D 补充的持续时间的安全性，以及相关的健康益处。
