由美国国立卫生研究院资助的一项研究表明：维生素D减少老鼠良性子宫肌瘤的大小。
子宫肌瘤是育龄妇女最常见的非癌性肿瘤。肌瘤主要生长在子宫壁内和周围。百分之三十的25至44岁女性年龄有肌瘤相关症状如腰痛、严重的阴道出血或月经周期疼痛。子宫肌瘤会导致不孕、流产或早产等怀孕并发症。手术切除子宫后，还有一些妇女会罹患子宫肌瘤相关症状，每年约20万美国妇女需要接受手术治疗。
美国黑人妇女罹患肌瘤的概率是白人妇女的三至四倍。此外，缺乏维生素D的非洲裔妇女罹患肌瘤的概率是白人妇女的10倍。以往研究中发现维生素D能抑制体外培养的人类子宫肌瘤细胞生长。
美国国立卫生研究院的尤尼斯肯尼施莱佛的生殖科学科主任Louis De Paolo博士说：“研究结果提供了一个新的非手术疗法来治疗子宫肌瘤，这种非手术疗法不影响生育”。
第一作者Sunil K. Halder博士与Chakradhari Sharan博士、Ayman Al-Hendy医学博士、纳什维尔的范德比尔特大学医学中心Kevin G. Osteen博士在纳什维尔梅哈里医学院一起完成了该项研究。研究结果刊登在Biology of Reproduction杂志上。
在这项研究中，研究人员探究了维生素D对有罹患纤维瘤易感基因的大鼠的作用。检查并确认其中有12只老鼠患有肌瘤后，研究人员将老鼠分为两组，每组六者，一组给予维生素D，一组不给当中对照组。
在第一组，植入皮肤下的小泵持续向老鼠体内输送连续剂量的维生素D，共持续三个星期。然后，研究人员检查两组动物。在未经处理的大鼠，肌瘤大小明显增加。但是，给予维生素D的大鼠，肿瘤体积已大幅缩水。平均而言，给予维生素D组的老鼠子宫肌瘤体积均比模型组小75％。
大鼠每天的维生素D量大约相当于人类的1400个国际单位的剂量。虽然4,000多个单位被认为对9岁以上儿童、成人、孕妇和哺乳期女性是安全的，但研究人员建议70岁成人和青少年摄取维生素D的量每天为600个单位。
Al-Hendy博士说：“需要更多的研究以确认维生素D对罹患子宫肌瘤的妇女潜在治疗作用，亨迪。维生素D也是维持肌肉、骨骼和免疫系统健康的重要养分，吸收足够量的维生素是很重要的。
如鲑鱼、鲭鱼和金枪鱼等富含脂肪的鱼是维生素最好的天然来源。极少数的食物会天然含有维生素D。阳光中的紫外线照射皮肤时，也产生维生素D。(生物谷：Bioon）
doi:10.1095/biolreprod.111.098145
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1,25-Dihydroxyvitamin D3 Treatment Shrinks Uterine Leiomyoma Tumors in the Eker Rat Model.
S. K. Halder, C. Sharan, A. Al-Hendy
Uterine leiomyomas (fibroids) are the most common benign tumors in women of reproductive age. These tumors are three to four times more prevalent in African American women, who also have a ten times higher incidence of hypovitaminosis D than white women. Recent studies have demonstrated the anti-tumor effects of 1,25-dihydroxyvitamin D3 on several cancers, but its effects on uterine leiomyomas are still unknown. To determine the anti-tumor and therapeutic effects of 1,25-dihydroxyvitamin D3 on uterine leiomyomas, female Eker rats (14-16 mo old) harboring uterine leiomyomas were randomized into control and experimental groups and were given vehicle versus 1,25-dihydroxyvitamin D3 (0.5 μg/kg/day) subcutaneously for three weeks, respectively. At the end of the experiment, the rats were sacrificed, and the leiomyoma tumors were analyzed. Treatment with 1,25-dihydroxyvitamin D3 significantly reduced leiomyoma tumor size in Eker rats. It also reduced leiomyoma size by suppressing cell growth and proliferation-related genes (Pcna, cyclin D1 [Ccnd1], Myc, Cdk1, Cdk2, and Cdk4), anti-apoptotic genes (Bcl2 and Bcl2l1 [Bcl-x]) and estrogen and progesterone receptors. Additionally, immunohistochemistry revealed decreased expression of PCNA and MKI67 (a marker of proliferation) and increased expression of caspase 3 in 1,25-dihydroxyvitamin D3-treated Eker rat leiomyomas. Toxicity analyses using serum samples showed similar levels of SGOT, SGPT, calcium and total bilirubin in 1,25-dihydroxyvitamin D3-treated and vehicle-treated control Eker rats. These results support that 1,25-dihydroxyvitamin D3 is an antitumor agent that may be a potential safe, non-surgical therapeutic option for the treatment of uterine leiomyomas.
