Observations on serum 25-hydroxyvitamin D and calcium concentrations from wild-caught and captive neotropical bats, Artibeus jamaicensis

Most bats of the suborder Microchiroptera are nocturnal, actively avoid sun light, and eat mineral-poor diets. In those bats previously studied with re spect to mineral metabolism, extensive bone remodeling occurs, and it has b een suggested that calcium has been an important constraint on reproduction . There have been no previous studies of vitamin D or its metabolites in mi crochiropteran bats with respect to calcium metabolism. Reported is the uti lization of current advances for the determination of serum levels of the v itamin D metabolite 25-hyroxyvitamin D (25-OH-D) in a neotropical bat, Arti beus jamaicensis. Serum from wild-caught animals contained low levels of 25 -OH-D (5.6 +/- 3.0 ng/ml, n = 8). Bats maintained on a vitamin-D-supplement ed diet had higher serum 25-OH-D levels and when the diet containing vitami n D was discontinued, mean serum 25-OH-D levels declined significantly afte r 6 months. Serum calcium concentrations in wild-caught bats (8.5 +/- 0.4 m g%) showed very little variation and were not significantly different in an y of the vitamin-D-supplemented animals. A pairwise correlation analysis be tween 25-OH-D and serum calcium levels revealed no linear correlation. The results indicate either that 25-OH-D does not appear to play a key role or that low levels of 25-OH-D may be adequate in regulating serum calcium leve ls in this bat. (C) 2001 Academic Press.