Circulating vitamin D3 and 25-hydroxyvitamin D in humans:: An important tool to define adequate nutritional vitamin D status
Circulating vitamin D3 and 25-hydroxyvitamin D in humans:: An important tool to define adequate nutritional vitamin D status
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DOI：
10.1016/j.jsbmb.2006.12.066
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发表时间：
2007-03-01
影响因子：
4.1
通讯作者：
Binkley, Neil C.
中科院分区：
文献类型：
--
作者：
Hollis, Bruce W.;Wagner, Carol L.;Binkley, Neil C.
通常认为循环 25-羟基维生素 D [25(OH)D] 是我们定义营养维生素 D 状态的方法。有很多争论。然而，关于健康的最低循环水平 25(OH)D 应该是多少。最近使用各种生物标志物（例如完整甲状旁腺激素 (PTH)、肠钙吸收和骨骼密度测量）的数据表明，该最低水平为 80 nmol (32 ng/mL)。令人惊讶的是，循环维生素 D-3 与其代谢产物 25(OH)D-3 之间的关系尚未得到研究。我们在两个不同的人群中研究了这种关系：第一个是来自夏威夷的接受大量阳光照射的个体；第二个是来自夏威夷的个体，他们接受了大量的阳光照射；第二个。来自哺乳期研究的受试者每天接受 6400 IU 维生素 D-3，持续 6 个月。 结果 (1) 两组中循环维生素 D-3 和 25(OH)D 之间的关系不是线性的，但似乎是饱和且受控的； (2) 当循环维生素 D-3 和 25(OH)D 的摩尔比超过 0.3 时，似乎出现最佳营养维生素 D 状态；此时，似乎已达到 25-羟化酶的 V-max。当循环 25(OH)D 超过 100 nmol 时，即可实现这一目标。我们假设，在当今人类生活中，由于慢性底物（即维生素 D-3）缺乏，25-羟化酶的运行远低于其 V-max。当人类阳光（或饮食）充足时，维生素 D 内分泌系统将以与其他类固醇合成途径相同的方式发挥作用，不受底物的限制。因此，循环维生素 D 和 25(OH)D 之间的关系可能代表“正常”维生素 D 状态。 (c) 2006 Elsevier Ltd. 保留所有权利。
Circulating 25-hydroxyvitamin D [25(OH)D] is generally considered the means by which we define nutritional vitamin D status. There is much debate. however, with respect to what a healthy minimum level of circulation 25(OH)D should be. Recent data using various biomarkers such as intact parathyroid hormone (PTH), intestinal calcium absorption, and skeletal density measurements suggest this minimum level to be 80 nmol (32 ng/mL). Surprisingly, the relationship between circulating vitamin D-3 and its metabolic product-25(OH)D-3 has not been studied. We investigated this relationship in two separate populations: the first, individuals from Hawaii who received significant sun exposure; the second. subjects from a lactation study who received up to 6400 IU vitamin D-3/day for 6 months.Results (1) the relationship between circulating vitamin D-3 and 25(OH)D in both groups was not linear, but appeared saturable and controlled; (2) optimal nutritional vitamin D status appeared to occur when molar ratios of circulating vitamin D-3 and 25(OH)D exceeded 0.3; at this point, the V-max of the 25-hydroxylase appeared to be achieved. This was achieved when circulating 25(OH)D exceeded 100 nmol.We hypothesize that as humans live today, the 25-hydroxylase operates well below its V-max because of chronic substrate deficiency, namely vitamin D-3. When humans are sun (or dietary) replete, the vitamin D endocrine system will function in a fashion as do these other steroid synthetic pathways, not limited by substrate. Thus, the relationship between circulating vitamin D and 25(OH)D may represent what "normal" vitamin D status should be. (c) 2006 Elsevier Ltd. All rights reserved.