Vitamin D binding protein is required to utilize skin-generated vitamin D.
Proc Natl Acad Sci U S A
; 116(49): 24527-24532, 2019 12 03.
Article
em En
| MEDLINE
| ID: mdl-31748273
ABSTRACT
Vitamin D is produced in the skin following exposure to sunlight. Ultraviolet (UV) B (UVB, 280-310 nm) results in isomerization of 7-dehydrocholesterol to previtamin D that spontaneously isomerizes to vitamin D. This pool of skin-derived vitamin D is the major source of vitamin D for animals. However, the mechanisms by which it becomes available remain undefined. It has been assumed that cutaneous vitamin D is transported into the circulation by vitamin D binding protein (DBP), but experimental evidence is lacking. To determine whether cutaneous vitamin D is transported by DBP, we utilized DBP-/- mice that were made vitamin D-deficient. These animals lack measurable 25(OH)D in blood and are hypocalcemic. As controls, DBP+/+ animals were vitamin D depleted and made equally hypocalcemic. UV irradiation of DBP+/+ animals restored serum calcium and serum 25(OH)D while the same treatment of DBP-/- animals failed to show either a serum calcium or 25(OH)D response despite having normal vitamin D production in skin. Intravenous injection of small amounts of recombinant DBP to the vitamin D-deficient DBP-/- mice restored the response to UV light. These results demonstrate a requirement for DBP to utilize cutaneously produced vitamin D.
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Base de dados:
MEDLINE
Assunto principal:
Pele
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Vitamina D
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Proteína de Ligação a Vitamina D
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article