通常理解，维生素D在施加与骨骼强度和病情相关的健康益处中起着作用。然而，该作用的重要性尚不清楚。对维生素D的许多误解可能导致歧义并应解决。

First, vitamin D is not really a vitamin. Vitamins are essential nutrients that the human body is incapable of producing. As such, vitamins must be obtained through diet. Vitamin D, on the other hand, is produced in mammalian skin upon exposure to UV rays from the sun.

Secondly, vitamin D is notdirectly负责施加与骨骼强度相关的健康益处。相反，维生素D转化为肝脏中的预激素，25-羟基vitamin d。该预激素在血液中循环，测量以确定个体的维生素D状态。然而，它（如维生素D）在正常生物条件下无活性。将预激素转化为活性激素（1,25-二羟基苯胺D）进行肾脏。已经在多种细胞和组织位点证明了​​活性激素（1,25-二羟基苯胺D）的生物学效应，其活性与钙维护有牢固连接。

第三，许多消费者和医疗保健提供者要么没有意识到或根本无法承认维生素D状态（当通过测量的血清预激素水平测量时，25-羟基vitamin d）并不一定与所有个人的相同健康结果相关。这种关于维生素D状态的低估细节是深入的黑人美国人的维生素D悖论：一种基于系统的调查临床实践，研究和公共卫生的方法 - 专家小组会议报告。

维生素D状态与骨骼健康之间的关系如何在人口的各个部分中不同？

Studies show that low measures of vitamin D status correlate to increased risk of osteopenia and fractures in White and Mexican-Americans, but measures of vitamin D status do not correlate to the same health outcomes in Black Americans. Despite markedly low measures of vitamin D status in Black Americans, the incidence of falls, fractures, or osteopenia are significantly lower compared to White American counterparts with similar vitamin D status. TheBMC诉讼程序报告描述了专家小组成员之间的讨论，显示黑人美国人从高剂量的维生素D补充剂中获得骨骼益处;高水平的维生素D状态的当前标志物几乎肯定会导致这群人群的不利影响。

Should Black Americans worry about low measures of vitamin D status?

有许多影响黑人美国人的维生素D状态和骨骼健康。提供的数据BMC诉讼程序报道表明，肥胖，皮肤色素沉着，遗传和环境都有助于对黑人美国人对白人美国人骨骼健康的维生素D状态的差异;但没有一个因素可以充分解释维生素D状态低于黑人美国骨骼健康的措施的重要性。更好地理解这些因素可能是了解改善所有人口中骨骼健康的机制的关键。

Where do we go from here?

Consumers and healthcare providers should appreciate the potential for adverse effects following over-supplementation with high doses of vitamin D in some individuals. While threshold values (deficient lower levels vs. safe upper levels) for individuals require further refinement, outcomes presented in theBMC诉讼程序报告suggest that the Recommended Daily Allowance values (400-600 IU/day) should be appropriate for most healthy populations.

Health scientists should appreciate the need to better understand the role of vitamin D and its significance in various segments of the population that are commonly underrepresented in clinical studies. A larger forum or workshop on the topic may help to stimulate more research on vitamin D with respect to bone health as well as implications beyond bone health.