Ohato M, Fujita T
Endocrinol Jpn. 1979 Jun;26(Suppl):7-13. doi: 10.1507/endocrj1954.26.supplement_7.
In elderly people with marginal exposure to the sunlight, males showed higher serum 25-hydroxycalciferol than females, whereas in those with ample or poor sunlight exposure, serum 25-hydroxycalciferol was higher or very low, respectively, exhibiting no sex difference in the vitamin D metabolite levels. The male predominance in serum 25-hydroxycalciferol levels seen among some aged population would be explained, at least in part, by the result of animal experiment suggesting the stimulatory effect of testosterone on vitamin D biosynthesis induced by ultaviolet irradiation. Testosterone was, furthermore, shown to have hypocalcemic action, probably through suppression of bone resortopton in vitamin D depleted but not in replete rats. Clinical implication of these two-fold effects of testosterone observed in rats was discussed in relevance to male predominance in serum 25-hydroxycalciferol level and bone mineral content in the aged population.
在日照较少的老年人中，男性血清25-羟维生素D水平高于女性；而在日照充足或不足的人群中，血清25-羟维生素D水平分别较高或极低，维生素D代谢产物水平不存在性别差异。部分老年人群中男性血清25-羟维生素D水平占优势，这至少可以部分地由动物实验结果来解释，该实验表明睾酮对紫外线照射诱导的维生素D生物合成具有刺激作用。此外，睾酮还表现出降钙作用，可能是通过抑制维生素D缺乏而非充足的大鼠的骨再吸收来实现的。本文结合老年人群中血清25-羟维生素D水平和骨矿物质含量方面男性占优势的情况，讨论了在大鼠中观察到的睾酮这两种作用的临床意义。
