Optimizing vitamin D in the elderly

描述(申请人提供)：在缺乏维生素D补充的情况下，维生素D缺乏症在老年人中非常普遍。现有的有限数据显示，在服用目前推荐的800IU/天维生素D时，补充维生素D的高龄、虚弱老年人仍有近25%的维生素D缺乏(25-OH D&lt；20 ng/mL)，个体间存在显著的差异性。本提案旨在对生活在受控生活环境中的虚弱老年人使用广泛的口服维生素D3剂量进行探索性研究。我们将通过随机、盲法调查来确定总的和非结合的25-OH维生素D3对补充维生素D3的剂量反应关系，每天剂量分别为800(目前推荐老年人)、2000和4000 IU或50,000 IU/周。我们还将比较每种剂量方案在达到25-OH维生素D水平&gt；20 ng/ml(50nmol/L)方面的效果，并找出导致剂量反应关系个体间差异的协变量。在骨质疏松症患者中，将分析完整甲状旁腺激素和骨吸收标志物(β-CTX)上游离25-羟基与总25-羟基的关系。我们还将检查炎性细胞因子的反应。一个长期目标是开发算法来估计D3剂量，以实现非常年长和虚弱个人的目标25-OH维生素D剂量。 公共卫生相关性：维生素D缺乏症在老年人中非常普遍，但对于非常年老或虚弱的人来说，使维生素D水平正常化所需的剂量尚未确定。这项提案将评估老年、高龄、虚弱和养老院患者对每天服用广泛剂量的维生素D3和每周服用更高剂量维生素D3的反应，以确定纠正住在养老院的近200万美国老年人维生素D缺乏症的最佳剂量。它还将探索哪些剂量的维生素D可以减少炎症和骨吸收。

DESCRIPTION (provided by applicant): Vitamin D deficiency is highly prevalent in older people in the absence of vitamin D supplementation. The limited data available show marked inter-individual variability in response to vitamin D supplementation in very old, frail elderly wih almost 25% remaining vitamin D deficient (25-OH D < 20 ng/mL) when receiving the currently recommended 800 IU/day vitamin D. This proposal is for exploratory research on the use of a wide range of oral vitamin D3 doses in frail elderly living in controlled living environments. We will determine the dose response relationship of total and unbound 25- OH vitamin D3 to supplemental vitamin D3 at daily doses of 800 (currently recommended for the elderly), 2000, and 4000 IU or 50,000 IU/weekly in a randomized blinded investigation We will also compare the efficacy of each dosing regimen in achieving 25-OH vitamin D levels >20 ng/mL (50 nmol/L) and identify covariates that contribute to inter-individual variation in the dose response relationship. In patients with osteoporosis, relationships between unbound vs. total 25-OH on intact parathyroid hormone and a marker of bone resorption (beta-Ctx) will be analyzed. We will also examine responses of inflammatory cytokines. A long-term goal is to develop algorithms for estimation of D3 dosages to achieve target 25-OH vitamin D doses for very elderly and frail individuals. PUBLIC HEALTH RELEVANCE: Vitamin D deficiency is very common in the elderly but the dose required to normalize vitamin D levels has not been determined for very old or frail people. This proposal will evaluate responses to a wide range of daily oral vitamin D3 doses and a higher weekly dose of oral vitamin D3 in old, very old, frail, and nursing home patients to determine the best dose to correct vitamin D deficiency in the almost 2 million elderly Americans living in nursing homes. It will also explore what doses of vitamin D decrease inflammation and bone resorption.