摘要：一项最新研究显示，男性每天足量服用维生素D，出现心脏问题或中风的几率降低。
这一结论以历时20多年、对近11.9万名成年人的随访为依据。研究人员发现，每天服用至少600国际单位（IU）维生素D的男性与每天摄入量少于100国际单位的男性相比，出现心脏问题或中风的几率低16%。
“国际单位”是多种类型维生素的计量单位，1国际单位相当于0.3微克。
这项研究由哈佛大学公共卫生学院孙褀（音译）博士领衔，报告发表于《美国临床营养学期刊》月刊。
鱼类、蛋类、添加了维生素和矿物质的“强化牛奶”以及鳕鱼肝油中维生素D含量较高。
孙褀在报告中写道，研究涉及的女性没有显示类似情况，原因不清楚。他提出一种可能，即女性血液中活跃循环的维生素D含量较少。维生素D部分储存在人体脂肪内，女性体内脂肪比例通常高于男性。
孙褀和其他报告作者认为，现有发现不足以证明维生素D能促使男性患心脏病风险降低，“证据不够强有力，不足以就此提出实质性建议”。
这项研究属于观察性研究，数据来源于两个美国卫生专业团体始于上世纪80年代的长期随访项目。
孙褀补充说，研究人员正着手一项抽样试验，评估是否每天摄入2000国际单位维生素D可降低心脏病、中风和其他慢性病风险。
生物探索推荐英文论文摘要：
Vitamin D intake and risk of cardiovascular disease in US men and women
Abstract
Background: Although studies have linked vitamin D deficiency to an increased risk of cardiovascular disease (CVD), evidence regarding whether vitamin D intake from foods or supplements is prospectively associated with lower CVD risk in healthy humans is limited and inconclusive.
Objective: The objective was to comprehensively evaluate the associations between both dietary and supplemental vitamin D and CVD risk.
Design: In the Nurses’ Health Study (1984–2006) and the Health Professionals Follow-Up Study (1986–2006)—consisting of 74,272 women and 44,592 men, respectively, who were free of CVD and cancer at baseline—we prospectively examined the association between vitamin D intake and incident CVD.
Results: Over a total of 2,280,324 person-years of follow-up, we identified 9886 incident cases of coronary heart disease and stroke. After multivariate adjustment for age and other CVD risk factors, a higher total vitamin D intake (from foods and supplements) was associated with a decreased risk of CVD in men but not in women; the relative risks (95% CIs) for a comparison of participants who met the Dietary Reference Intake of vitamin D (≥600 IU/d) with participants whose vitamin D intake was <100 IU/d were 0.84 (0.72, 0.97; P for trend = 0.009) for men and 1.02 (0.89, 1.17; P for trend = 0.12) for women.
Conclusions: These observations suggest that a higher intake of vitamin D is associated with a lower risk of CVD in men but not in women. Further research is needed to confirm these findings and to elucidate a biological basis for potential sex differences.
