Singh Gurmukh, Bonham Aaron J
From the Department of Pathology, Truman Medical Center (GS), and the Office for Health Services & Public Health Outcomes Research, Department of Biomedical and Health Informatics (AJB), University of Missouri-Kansas City School of Medicine, Kansas City, MO; and Heritage Laboratories International Inc., Olathe, KS (GS).
J Am Board Fam Med. 2014 Jul-Aug;27(4):495-509. doi: 10.3122/jabfm.2014.04.130306.
Vitamin D is essential for bone health and probably the health of most nonskeletal tissues. Vitamin D deficiency is widespread, and recommended doses are usually inadequate to maintain healthy levels. We conducted a retrospective observational study to determine whether the recommended doses of vitamin D are adequate to correct deficiency and maintain normal levels in a population seeking health care. We also sought to develop a predictive equation for replacement doses of vitamin D.
We reviewed the response to vitamin D supplementation in 1327 patients and 3885 episodes of vitamin D replacement and attempted to discern factors affecting the response to vitamin D replacement by conducting multiple regression analyses.
For the whole population, average daily dose resulting in any increase in serum 25-hydroxyvitamin D level was 4707 IU/day; corresponding values for ambulatory and nursing home patients were 4229 and 6103 IU/day, respectively. Significant factors affecting the change in serum concentrations of 25-hydroxyvitamin D, in addition to the dose administered, are (1) starting serum concentration of 25-hydroxyvitamin D, (2) body mass index (BMI), (3) age, and (f) serum albumin concentration. The following equation predicts the dose of vitamin D needed (in international units per day) to affect a given change in serum concentrations of 25-hydroxyvitamin D: Dose = [(8.52 - Desired change in serum 25-hydroxyvitamin D level) + (0.074 × Age) - (0.20 × BMI) + (1.74 × Albumin concentration) - (0.62 × Starting serum 25-hydroxyvitamin D concentration)]/(-0.002). Analysis of the dose responses among 3 racial groups-white, black, and others-did not reveal clinically meaningful differences between the races. The main limitation of the study is its retrospective observational nature; however, that is also its strength in that we assessed the circumstances seen in usual health care setting.
The recommended daily allowance for vitamin D is grossly inadequate for correcting low serum concentrations of 25-hydroxyvitamin D in many adult patients. About 5000 IU vitamin D3/day is usually needed to correct deficiency, and the maintenance dose should be ≥2000 IU/day. The required dose may be calculated from the predictive equations specific for ambulatory and nursing home patients.
维生素D对骨骼健康至关重要，可能对大多数非骨骼组织的健康也很重要。维生素D缺乏症普遍存在，推荐剂量通常不足以维持健康水平。我们进行了一项回顾性观察研究，以确定维生素D的推荐剂量是否足以纠正缺乏症并在寻求医疗保健的人群中维持正常水平。我们还试图建立一个维生素D替代剂量的预测方程。
我们回顾了1327例患者和3885次维生素D替代治疗的反应，并通过多元回归分析试图识别影响维生素D替代治疗反应的因素。
对于整个人群，导致血清25-羟基维生素D水平有任何升高的平均每日剂量为4707IU/天；门诊患者和疗养院患者的相应值分别为4229IU/天和6103IU/天。除了给药剂量外，影响血清25-羟基维生素D浓度变化的重要因素有：（1）25-羟基维生素D的起始血清浓度；（2）体重指数（BMI）；（3）年龄；（4）血清白蛋白浓度。以下方程可预测影响血清25-羟基维生素D浓度给定变化所需的维生素D剂量（以国际单位/天计）：剂量 = [（8.52 - 血清25-羟基维生素D水平的期望变化）+（0.074×年龄）-（0.20×BMI）+（1.74×白蛋白浓度）-（0.62×25-羟基维生素D起始血清浓度）]/（-0.002）。对白人、黑人及其他三个种族的剂量反应分析未发现种族之间存在具有临床意义的差异。该研究的主要局限性在于其回顾性观察性质；然而，这也是其优势所在，因为我们评估了常规医疗保健环境中的情况。
维生素D的推荐每日摄入量严重不足以纠正许多成年患者低血清25-羟基维生素D浓度的情况。通常需要约5000IU/天的维生素D3来纠正缺乏症，维持剂量应≥2000IU/天。所需剂量可根据针对门诊患者和疗养院患者的预测方程计算得出。
