Ultraviolet Light Exposure and Response to Dietary Vitamin D3in Two Jamaican Anoles

Abstract

Abstract In Jamaica, free-living male and female-sized Anolis sagrei are exposed to more natural ultraviolet-B (UVB) from sunlight than male and female-sized Anolis lineatopus. In the laboratory, we tested predictions derived from the hypothesis that Anolis possess a mechanism for behaviorally photo-regulating their exposure to UVB depending on their dietary intake of vitamin D3. Anolis sagrei voluntarily exposed themselves more frequently to visible and UVB light and received higher doses of UVB in an artificial light gradient when fed a low vitamin D3 diet for 6 weeks than when subsequently fed a high dietary vitamin D3 diet for 6 weeks. When we returned the anole's diet to the low vitamin D3 regimen for a third 6-week period, UVB exposure remained lower than in the first 6-week period. This suggests an initial UV photo-regulatory adjustment to high dietary vitamin-D3 but a slow return to greater reliance on UVB-induced endogenous vitamin D3 production. Conversely, while exposing themselves to UVB with ...