{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T13:18:03Z","timestamp":1783516683200,"version":"3.55.0"},"reference-count":0,"publisher":"Bioscientifica","issue":"2","content-domain":{"domain":["journals.bioscientifica.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1994,11,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Vitamin D may be endogenously synthezised in the skin in the presence of sunlight or, alternatively, acquired from dietary sources. Cryptomys damarensis appear to have a naturally impoverished vitamin D status with low plasma concentrations of both 25-hydroxyvitamin D (25(OH)D; &amp;lt;5 ng\/ml) and 1,25-dihydroxyvitamin D (1,25(OH)2D; &amp;lt;20 pg\/ml). We attribute this to their underground habitat and herbivorous habits. We questioned whether these subterranean mammals could utilize sunlight-mediated pathways and therefore compared vitamin D metabolism and function when animals were (a) housed naturally (control), (b) given an oral vitamin D3 (D3) supplement (1 IU\/g dry matter food eaten per day) and (c) exposed to 10 h of sunlight. Control animals exhibited a highly efficient apparent fractional absorption of both calcium (Ca) and inorganic phosphorus (Pi) (&amp;gt;90%), passive mode of intestinal mineral uptake, yet tightly regulated serum ionized calcium (Ca2+). The ratio of 25(OH)D-1\u03b1-hydroxylase (1-OHase) to 25(OH)D-24R-hydroxylase (24-OHase) activity in the kidney, corresponded with a state of vitamin D deficiency. Cryptomys damarensis responded to both oral D3 supplementation and sun exposure by an increase in plasma concentration of 1,25(OH)2D with a commensurate decline (P&amp;lt;0\u00b705) in 1-OHase activity, and a resulting decrease (P&amp;lt;0\u00b705) in the ratio of 1-OHase:24-OHase activity. Despite these changes, the intestinal mode of Ca uptake and plasma total Ca, Ca2+ and Pi remained unchanged with either treatment. Responses to sunlight were less pronounced than that of oral D3 supplementation. These data confirm that naturally vitamin D-deficient mole-rats can convert vitamin D to the active hormone 1,25(OH)2D, and indicate that mole-rats function optimally at the low concentrations of vitamin D metabolites found naturally. Furthermore, these animals exhibit a highly efficient vitamin D-independent mode of intestinal Ca absorption.<\/jats:p>\n                  <jats:p>Journal of Endocrinology (1994) 143, 367\u2013374<\/jats:p>","DOI":"10.1677\/joe.0.1430367","type":"journal-article","created":{"date-parts":[[2008,12,11]],"date-time":"2008-12-11T18:11:46Z","timestamp":1229019106000},"page":"367-374","update-policy":"https:\/\/doi.org\/10.1530\/crossmarkpolicy-5","source":"Crossref","is-referenced-by-count":8,"title":["Vitamin D metabolism in the Damara mole-rat is altered by exposure to sunlight yet mineral metabolism is unaffected"],"prefix":"10.1530","volume":"143","author":[{"given":"T","family":"Pitcher","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"I N","family":"Sergeev","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R","family":"Buffenstein","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"416","container-title":["Journal of Endocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/joe.bioscientifica.com\/view\/journals\/joe\/143\/2\/joe_143_2_019.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.bioscientifica.com\/joe\/article-pdf\/143\/2\/367\/103474\/joe_143_2_019.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/journals.bioscientifica.com\/joe\/article-pdf\/143\/2\/367\/103474\/joe_143_2_019.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T12:46:03Z","timestamp":1783514763000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.bioscientifica.com\/joe\/article\/143\/2\/367\/18127\/Vitamin-D-metabolism-in-the-Damara-mole-rat-is"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,11,1]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1994,11,1]]}},"URL":"https:\/\/doi.org\/10.1677\/joe.0.1430367","relation":{},"ISSN":["1479-6805","0022-0795"],"issn-type":[{"value":"1479-6805","type":"electronic"},{"value":"0022-0795","type":"print"}],"subject":[],"published":{"date-parts":[[1994,11,1]]}}}