TY - JOUR
T1 - Vitamin D metabolism in a frugivorous nocturnal mammal, the Egyptian fruit bat (Rousettus aegyptiacus)
AU - Cavaleros, Meropi
AU - Buffenstein, Rochelle
AU - Ross, F. Patrick
AU - Pettifor, John M.
N1 - Funding Information:
Sincere thanks to Dr J. van der Westhuizen for kindly catching the wild bats and to the Animal Unit of the SAIMR, Johannesburg for housing and caring for the animals used in this study. Financial support from the South African Medical Research Council and the University of the Witwatersrand is gratefully acknowledged.
PY - 2003/8/1
Y1 - 2003/8/1
N2 - The nocturnal, frugivorous Egyptian fruit bat (Rousettus aegyptiacus) has no obvious access to either endogenous or dietary sources of vitamin D. We hypothesized that this species under natural conditions would be vitamin D deficient and that both serum mineral concentrations and vitamin D metabolite concentrations would be low. Both wild populations and captive populations appear to have an impoverished vitamin D status, as concentrations of the principle circulating metabolite, 25-hydroxyvitamin D [25(OH)D] are undetectable (<4ng/mL) and those of the active metabolite, 1, 25-dihydroxyvitamin D [1, 25(OH)2D] are low. Intraperitoneal administration of labelled 25(OH)D revealed enhanced 1 α-hydroxylase activity confirming a natural state of vitamin D deficiency. This may account for the undetectable levels of 25(OH)D; for limited amounts of the prohormone substrate are rapidly converted to the active hormone. Both vitamin D2 and D3 metabolites were detected in bat serum, albeit in very small amounts, inferring that in their natural habitat fruit bats may have limited access to both exogenous dietary sources and endogenous sources. Despite the low levels of vitamin D metabolites in wild-caught and captive D-unsupplemented individuals, serum mineral concentrations were well regulated and similar to those of bats receiving D-supplements, with no pathological problems associated with vitamin D deficiency evident.
AB - The nocturnal, frugivorous Egyptian fruit bat (Rousettus aegyptiacus) has no obvious access to either endogenous or dietary sources of vitamin D. We hypothesized that this species under natural conditions would be vitamin D deficient and that both serum mineral concentrations and vitamin D metabolite concentrations would be low. Both wild populations and captive populations appear to have an impoverished vitamin D status, as concentrations of the principle circulating metabolite, 25-hydroxyvitamin D [25(OH)D] are undetectable (<4ng/mL) and those of the active metabolite, 1, 25-dihydroxyvitamin D [1, 25(OH)2D] are low. Intraperitoneal administration of labelled 25(OH)D revealed enhanced 1 α-hydroxylase activity confirming a natural state of vitamin D deficiency. This may account for the undetectable levels of 25(OH)D; for limited amounts of the prohormone substrate are rapidly converted to the active hormone. Both vitamin D2 and D3 metabolites were detected in bat serum, albeit in very small amounts, inferring that in their natural habitat fruit bats may have limited access to both exogenous dietary sources and endogenous sources. Despite the low levels of vitamin D metabolites in wild-caught and captive D-unsupplemented individuals, serum mineral concentrations were well regulated and similar to those of bats receiving D-supplements, with no pathological problems associated with vitamin D deficiency evident.
KW - 1, 25-Dihydroxyvitamin D
KW - 25-Hydroxyvitamin D
KW - Egyptian fruit bat
KW - Rousettus aegyptiacus
KW - Serum calcium concentration
KW - Vitamin D
KW - Vitamin D binding protein
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U2 - 10.1016/S0016-6480(03)00150-3
DO - 10.1016/S0016-6480(03)00150-3
M3 - Article
C2 - 12899852
AN - SCOPUS:0043166350
VL - 133
SP - 109
EP - 117
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
SN - 0016-6480
IS - 1
ER -