Vitamin D Levels in Captive Bonnet Macaques

ABSTRACT Introduction Vitamin D is essential for calcium–phosphate homeostasis, bone health, and immune regulation. Its primary source is UVB‐induced cutaneous synthesis, and deficiency is associated with impaired bone mineralization. Materials and Methods Serum vitamin D levels were assessed in bonnet macaques ( Macaca radiata ) housed indoors (limited UVB exposure) and outdoors (natural UVB exposure). Blood samples were collected during routine monitoring, and vitamin D levels were measured using LC–MS/MS. Vitamin D–deficient indoor animals received intramuscular supplementation (30 000 IU) on Days 0 and 14. Results Indoor‐housed macaques exhibited lower serum vitamin D levels compared to outdoor animals. Post‐supplementation, vitamin D levels increased significantly in treated animals.