Perry H M, Horowitz M, Morley J E, Patrick P, Vellas B, Baumgartner R, Garry P J
Geriatric Research, Education and Clinical Center, St. Louis Veterans Affairs Medical Center, and St. Louis University Medical School, MO, USA.
Metabolism. 1999 Aug;48(8):1028-32. doi: 10.1016/s0026-0495(99)90201-9.
Cross-sectional studies have suggested that serum 25-hydroxyvitamin D (25OHD) levels decline with aging. We have examined this putative decline in a longitudinal study using participants in the New Mexico Aging Process Study. 25OHD levels were measured in participants in whom serum samples were available between 1980 to 1982 and 1989 to 1994 (37 men and 99 women). The available data for these visits included age, gender, and the date the sample was obtained. Questionnaires assessing physical activity and vitamin D intake were administered at the visits. A seasonal variation (r = .25, P < .05) in 25OHD was demonstrated in the whole group of subjects. In 25 subjects who were not receiving vitamin D supplementation at either time and had samples obtained in the same season, both serum 25OHD (P < .05) and physical activity (P < .05) decreased over a mean period of 11.4 years. In 23 subjects who had samples obtained in the same season but used vitamin D supplements at both times, there was no change in serum 25OHD. Mean summer 25OHD levels did not change with the duration of study. On the other hand, the mean serum 25OHD declined with the duration of study when measured from winter to winter or spring to spring. Multiple regression analysis demonstrated that the month, activity level, vitamin D supplementation, and gender (P < .001) were independent determinants of serum 25OHD levels. This study confirms that aging is associated with a reduction in serum 25OHD, and suggests that this decrease is a reflection of reduced sun exposure rather than aging per se. The reduction in serum 25OHD was the result of decreasing winter and spring 25OHD serum concentrations. It is clear that vitamin D supplementation can prevent the age-related decline in 25OHD levels.
横断面研究表明，血清25-羟基维生素D（25OHD）水平会随着年龄增长而下降。我们利用新墨西哥衰老过程研究中的参与者，在一项纵向研究中对这种假定的下降情况进行了检验。对1980年至1982年以及1989年至1994年期间有血清样本的参与者（37名男性和99名女性）测量了25OHD水平。这些访视的可用数据包括年龄、性别以及样本采集日期。在访视时发放了评估身体活动和维生素D摄入量的问卷。在整个研究对象组中发现25OHD存在季节性变化（r = 0.25，P < 0.05）。在25名两次均未补充维生素D且在同一季节采集样本的受试者中，血清25OHD（P < 0.05）和身体活动水平（P < 0.05）在平均11.4年的时间里均有所下降。在23名在同一季节采集样本但两次均使用维生素D补充剂的受试者中，血清25OHD没有变化。夏季的平均25OHD水平未随研究时长而改变。另一方面，从冬季到冬季或春季到春季测量时，平均血清25OHD随研究时长而下降。多元回归分析表明，月份、活动水平、维生素D补充情况和性别（P < 0.001）是血清25OHD水平的独立决定因素。这项研究证实衰老与血清25OHD水平降低有关，并表明这种下降反映的是日照减少而非衰老本身。血清25OHD水平降低是冬季和春季血清25OHD浓度下降的结果。显然，补充维生素D可以预防与年龄相关的25OHD水平下降。
