Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA,
Ringling Brothers and Barnum & Bailey Center for Elephant Conservation, Polk City, Florida 33868, USA.
J Zoo Wildl Med. 2024 Jun;55(2):430-435. doi: 10.1638/2023-0082.
An understanding of species-specific vitamin D metabolism and its role in calcium homeostasis is essential for correct diet formulation and development of husbandry protocols for managed nondomestic species. This study documented serum vitamin D metabolites and other analytes involved in calcium homeostasis in Asian elephants () managed at a latitude similar to their wild natural habitat. Serum values for 33 elephants managed at a low latitude were measured in the peak of summer, revealing low vitamin D (25(OH)D 2.3 ± 0.6 ng/ ml and 24,25(OH)D 2.17 ± 0.52 ng/ml) and nondetectable vitamin D. Serum minerals (calcium, phosphorus, magnesium), ionized calcium, and parathyroid hormone were within normal reported ranges. In comparison with previously reported values in elephants managed at a high latitude, 25(OH)D ( < 0.001), 24,25(OH)D ( = 0.001), and magnesium ( = 0.013) were significantly lower, and parathyroid hormone was significantly higher ( < 0.001). The lack of D production during ample sun exposure at a low latitude suggests that Asian elephants are incapable of cutaneous photobiosynthesis of vitamin D, and that low serum D is normal for this species.
了解物种特异性维生素 D 代谢及其在钙稳态中的作用，对于正确制定饮食配方和制定管理非本地物种的畜牧业协议至关重要。本研究记录了在类似于其野生自然栖息地的纬度管理下的亚洲象（）的血清维生素 D 代谢物和其他参与钙稳态的分析物。在夏季高峰期测量了在低纬度管理的 33 头大象的血清值，结果显示维生素 D 水平较低（25(OH)D 为 2.3 ± 0.6ng/ml，24,25(OH)D 为 2.17 ± 0.52ng/ml），且维生素 D 无法检测到。血清矿物质（钙、磷、镁）、离子钙和甲状旁腺激素均在正常报告范围内。与在高纬度管理的大象中之前报告的值相比，25(OH)D（<0.001）、24,25(OH)D（=0.001）和镁（=0.013）显著降低，而甲状旁腺激素显著升高（<0.001）。在低纬度有充足阳光照射的情况下缺乏 D 生成表明，亚洲象无法进行皮肤光生物合成维生素 D，并且低血清 D 是该物种的正常现象。
