Adami Silvano, Viapiana Ombretta, Gatti Davide, Idolazzi Luca, Rossini Maurizio
Rheumatologic Rehabilitation, University of Verona, Italy.
Bone. 2008 Feb;42(2):267-70. doi: 10.1016/j.bone.2007.10.003. Epub 2007 Oct 16.
Vitamin D deficiency is extremely common among elderly subjects and it has been associated with poor bone health, and to a number of other conditions. The ideal 25-hydroxy-vitamin D [25(OH)D] concentration, reflecting the size of vitamin D deposits, are generally retained those not associated with any marginal increase in serum parathyroid hormone (PTH). These threshold values vary considerably and this may be due to the interaction of other factors. The aim of the study is to assess whether age and calcium intake interact with the relationship between 25(OH)D and PTH. Data from a survey on the prevalence of hypovitaminosis D in elderly women in Italy were analysed in order to verify whether age and calcium intake were interfering on the 25(OH)D/PTH relationship. A total of 697 women were available for analysis. Serum PTH levels were significantly correlated with age, 25(OH)D and calcium intake (p<0.001) and in a multivariate model they all significantly contributed to explain PTH variance (R(2)=24.4%). In 39 elderly osteoporotic women on a low calcium intake and given vitamin D supplements (2000-3000 IU daily for >8 months) able to increase 25(OH)D levels above 110 nMol/l, PTH levels were maintained below 35 pg/mL. The minimum 25(OH)D levels to be recommended depends largely on the age and the calcium intake. In elderly individuals not taking calcium supplements in order to keep serum PTH levels strictly within the normal range 25(OH)D serum levels should be maintained above ca. 120 nMol/L.
维生素D缺乏在老年人群中极为常见，且与骨骼健康不佳及许多其他病症相关。反映维生素D储备量的理想25-羟维生素D[25(OH)D]浓度，通常是那些与血清甲状旁腺激素（PTH）无任何轻微升高相关的浓度。这些阈值差异很大，这可能是由于其他因素的相互作用。本研究的目的是评估年龄和钙摄入量是否会与25(OH)D和PTH之间的关系相互作用。分析了意大利老年女性维生素D缺乏症患病率调查的数据，以验证年龄和钙摄入量是否会干扰25(OH)D/PTH关系。共有697名女性可供分析。血清PTH水平与年龄、25(OH)D和钙摄入量显著相关（p<0.001），在多变量模型中，它们都对解释PTH变异有显著贡献（R(2)=24.4%）。在39名低钙摄入且服用维生素D补充剂（每日2000 - 3000 IU，持续>8个月）的老年骨质疏松女性中，25(OH)D水平能够升高至110 nMol/l以上，PTH水平维持在35 pg/mL以下。建议的最低25(OH)D水平在很大程度上取决于年龄和钙摄入量。对于未服用钙补充剂的老年人，为了将血清PTH水平严格维持在正常范围内，血清25(OH)D水平应维持在约120 nMol/L以上。
