Department of Medicine, University of Auckland, Auckland, New Zealand.
Am J Clin Nutr. 2011 Oct;94(4):1144-9. doi: 10.3945/ajcn.111.015032. Epub 2011 Aug 31.
Frequent use of personal, nonprotocol calcium supplements obscured an adverse effect of coadministered calcium and vitamin D (CaD) on cardiovascular risk in the Women's Health Initiative (WHI).
We investigated the effects of the use of personal calcium or vitamin D supplements on other outcomes in the WHI CaD Study (WHI CaD) by using the WHI limited-access clinical trials data set.
The WHI CaD was a 7-y, randomized, placebo-controlled trial of CaD (1 g Ca/400 IU vitamin D daily) in 36,282 community-dwelling, postmenopausal women. The incidence of total cancer (excluding nonmelanoma skin cancers), breast and colorectal cancers, hip and total fracture, and mortality was assessed by using Cox proportional hazards models.
In the WHI CaD, interactions between the use of either personal calcium or vitamin D supplements and CaD were found for total, breast, and colorectal cancers but not for fracture or mortality. In 15,646 women (43%) who were not taking personal calcium or vitamin D supplements at randomization, CaD significantly decreased the risk of total, breast, and invasive breast cancers by 14-20% and nonsignificantly reduced the risk of colorectal cancer by 17%. In women taking personal calcium or vitamin D supplements, CaD did not alter cancer risk (HR: 1.06-1.26).
For women in the WHI CaD who were not taking personal calcium or vitamin D supplements at randomization, CaD decreased the risk of total, breast, and colorectal cancers and did not change the risk of fractures or total mortality. The nonskeletal effects of CaD may be more important than the skeletal effects and should be considered when evaluating these supplements. The WHI CaD trial is registered at clinicaltrials.gov as NCT00000611.
频繁使用个人的、非方案规定的钙补充剂掩盖了同时服用钙和维生素 D（CaD）对妇女健康倡议（WHI）心血管风险的不良影响。
我们使用 WHI 有限访问临床试验数据集调查了 WHI CaD 研究（WHI CaD）中个人钙或维生素 D 补充剂使用对其他结果的影响。
WHI CaD 是一项为期 7 年、随机、安慰剂对照的 CaD（每天 1 克钙/400IU 维生素 D）试验，纳入了 36282 名居住在社区的绝经后妇女。采用 Cox 比例风险模型评估总癌症（不包括非黑色素瘤皮肤癌）、乳腺癌和结直肠癌、髋部和总骨折以及死亡率的发生率。
在 WHI CaD 中，发现个人钙或维生素 D 补充剂的使用与 CaD 之间存在总癌症、乳腺癌和结直肠癌的相互作用，但与骨折或死亡率无关。在 15646 名（43%）在随机分组时未服用个人钙或维生素 D 补充剂的妇女中，CaD 显著降低了总癌症、乳腺癌和浸润性乳腺癌的风险 14-20%，结直肠癌的风险降低了 17%，但无统计学意义。在服用个人钙或维生素 D 补充剂的妇女中，CaD 并未改变癌症风险（HR：1.06-1.26）。
对于在 WHI CaD 中随机分组时未服用个人钙或维生素 D 补充剂的妇女，CaD 降低了总癌症、乳腺癌和结直肠癌的风险，且并未改变骨折或总死亡率的风险。CaD 的非骨骼作用可能比骨骼作用更重要，在评估这些补充剂时应予以考虑。WHI CaD 试验在 clinicaltrials.gov 上注册，编号为 NCT00000611。
