Higher Vitamin D Levels Linked to Breast Cancer Survival Rates

Amy Capetta2016/11/15英语学习

摘要: 一项发表于《JAMA 肿瘤学》的研究表明,乳腺癌确诊后血液中维生素D水平较高的女性,其总体生存率、乳腺癌特异性生存率及无复发生存率显著优于维生素D水平较低者,尤其在绝经前女性中效果更为明显。

  • 在1,666名乳腺癌患者中,维生素D水平最高组的乳腺癌特异性生存率提高63%,无复发生存率提高48%。
  • 研究随访中位时间为7年,发现较高维生素D水平与更低的总体死亡率相关。
  • 维生素D可能通过支持免疫系统功能影响乳腺癌预后,但研究未区分食物与补充剂来源的维生素D效果。
  • 专家建议通过血液检测(25-羟基维生素D)评估个体维生素D状态,并在医生指导下适当补充。

小白老师说:Yes, vitamin D has made the news once again. According to a study published online in JAMA Oncology, women with higher vitamin D levels in their blood following a breast cancer diagnosis had significantly better survival rates.

Higher Vitamin D Levels Linked to Better Breast Cancer Survival Rates

While vitamin D—which is also referred to as the “sunshine vitamin”—is mostly known for its role in the proper development of bones and teeth, a vitamin D deficiency has been linked to an increased risk of various cancers, as well as chronic conditions such as asthma.

Over a seven-year period, researchers from Kaiser Permanente and Roswell Park Cancer Institute analyzed blood samples of 1,666 women who had been diagnosed with invasive breast cancer in 2006 (the year the study began). The samples were provided within two months of their diagnosis. The participants also answered questions about their diets and lifestyles, as well as other risk factors (i.e., race, obesity, age).

Investigators followed up with these women five times throughout the study period. They learned that in addition to lower overall mortality among all breast cancer survivors studied, there were even stronger positive associations among premenopausal women in the highest third of vitamin D levels for breast-cancer-specific (63 percent better) and recurrence-free (48 percent better) participants during a median follow-up of seven years.

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“I think these findings are intriguing, and I agree that it’s consistent with what we’ve learned about vitamin D over the last few years — that it does seem to have a role in maintaining the immune system,” said Dennis R. Holmes, MD, breast cancer surgeon and researcher and interim director of the Margie Petersen Breast Center at the John Wayne Cancer Institute at Providence Saint John’s Health Center in Santa Monica, Calif. “We haven’t had strong data to indicate that there was a link to breast cancer — one that was compelling, at least — but this finding is certainly compelling,” he told Yahoo Beauty.

The scientists in this latest study did not examine the effects of vitamin D consumption from food versus supplements. However, their research supports recommended daily levels of vitamin D — 600 IU for those 1 to 70 years old and pregnant or breastfeeding women, and 800 IU for those over 71 years old.

But there is conflicting information from the medical community regarding the proper daily dosage for this nutrient. In fact, just this week, experts wrote in the New England Journal of Medicine that misunderstandings about the recommended amount of vitamin D have led to misinterpretation of blood tests and many people thinking they need more than they really do.

Holmes believes that most people, especially those who are health-conscious, are not receiving enough of the vitamin. “The normal healthy lifestyle we pursue tends to include eating less dairy products [fortified milk is a common source],” he explains. Other common practiced healthy behaviors include swapping soy milk for regular milk, as well as wearing sunscreen, “and those things are undermining the effort to increase vitamin D and maintain normal vitamin D levels.”

He advises speaking with your doctor about whether or not a blood test (25-Hydroxyvitamin D, or the 25OHD) should be performed. “And if the physician encourages it — which I think many will — to supplement appropriately.”

常见问题

维生素D如何影响乳腺癌患者的生存率?

研究显示,确诊后维生素D水平较高的乳腺癌患者,尤其是绝经前女性,其乳腺癌特异性生存率和无复发生存率显著更高,提示维生素D可能在改善预后中起积极作用。

乳腺癌患者是否应该补充维生素D?

专家建议先通过25-羟基维生素D血液检测评估维生素D水平,并在医生指导下决定是否补充;目前推荐摄入量为1–70岁人群每日600 IU,71岁以上为800 IU。

为什么现代人容易缺乏维生素D?

健康生活方式如减少乳制品摄入(如用豆奶替代强化牛奶)、频繁使用防晒霜等行为会减少维生素D的自然合成与摄取,导致水平不足。

参考资料

Association of Vitamin D Levels With Outcome in Patients With Breast Cancer

发表于《JAMA Oncology》的原始研究,分析1,666名乳腺癌患者的维生素D水平与生存结局关系。

Vitamin D Supplementation and Health Outcomes

《新英格兰医学杂志》近期指出公众对维生素D推荐剂量存在误解,可能导致过度补充或误判缺乏状态。