Department of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA; Department of Physiology, University of California, Los Angeles (UCLA), Los Angeles, CA; Department of Orthopaedic Surgery, University of California, Los Angeles (UCLA), Los Angeles, CA.
Department of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA; Department of Physiology, University of California, Los Angeles (UCLA), Los Angeles, CA; Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA; VA Greater Los Angeles Healthcare System, Los Angeles, Los Angeles, CA.
Am Heart J. 2021 Sep;239:147-153. doi: 10.1016/j.ahj.2021.05.012. Epub 2021 May 27.
The role of vitamin D in the cardiovascular system is complex because it regulates expression of genes involved in diverse metabolic processes. Although referred to as a vitamin, it is more accurately considered a steroid hormone, because it is produced endogenously in the presence of ultraviolet light. It occurs as a series of sequentially activated forms, here referred to as vitamin D-hormones. A little-known phenomenon, based on pre-clinical data, is that its biodistribution and potential effects on vascular disease likely depend on whether it is derived from diet or sunlight. Diet-derived vitamin D-hormones are carried in the blood, at least in part, in chylomicrons and lipoprotein particles, including low-density lipoprotein. Since low-density lipoprotein is known to accumulate in the artery wall and atherosclerotic plaque, diet-derived vitamin D-hormones may also collect there, and possibly promote the osteochondrogenic mineralization associated with plaque. Also, little known is the fact that the body stores vitamin D-hormones in adipose tissue with a half-life on the order of months, raising doubts about whether the use of the term "daily requirement" is appropriate. Cardiovascular effects of vitamin D-hormones are controversial, and risk appears to increase with both low and high blood levels. Since low serum vitamin D-hormone concentration is reportedly associated with increased cardiovascular and orthopedic risk, oral supplementation is widely used, often together with calcium supplements. However, meta-analyses show that oral vitamin D-hormone supplementation does not protect against cardiovascular events, findings that are also supported by a randomized controlled trial. These considerations suggest that prevalent recommendations for vitamin D-hormone supplementation for the purpose of cardiovascular protection should be carefully reconsidered.
维生素 D 在心血管系统中的作用较为复杂，因为它可以调节多种代谢过程相关基因的表达。尽管维生素 D 常被称为一种维生素，但它更准确地被认为是一种类固醇激素，因为它是在紫外线存在的情况下由体内产生的。它以一系列连续激活的形式存在，在这里被称为维生素 D 激素。一个鲜为人知的现象是，基于临床前数据，其分布和对血管疾病的潜在影响可能取决于它是来自饮食还是阳光。饮食来源的维生素 D 激素在血液中，至少部分是在乳糜微粒和脂蛋白颗粒中携带的，包括低密度脂蛋白。由于已知低密度脂蛋白在动脉壁和动脉粥样硬化斑块中积累，饮食来源的维生素 D 激素也可能在那里积累，并可能促进与斑块相关的成骨软骨矿化。此外，人们还不太了解这样一个事实，即身体将维生素 D 激素储存在脂肪组织中，半衰期为数月，这使人对“每日需求量”这一术语的使用是否合适产生了怀疑。维生素 D 激素对心血管的影响存在争议，风险似乎随着血液水平的降低和升高而增加。由于低血清维生素 D 激素浓度与心血管和骨科风险增加有关，因此广泛使用口服补充剂，通常与钙补充剂一起使用。然而，荟萃分析表明，口服维生素 D 激素补充剂不能预防心血管事件，随机对照试验也支持这一发现。这些考虑表明，为了心血管保护而普遍建议补充维生素 D 激素的做法应仔细重新考虑。
