Morton D J, Barrett-Connor E L, Schneider D L
Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, USA.
J Bone Miner Res. 2001 Jan;16(1):135-40. doi: 10.1359/jbmr.2001.16.1.135.
Vitamin C is known to stimulate procollagen, enhance collagen synthesis, and stimulate alkaline phosphatase activity, a marker for osteoblast formation. Studies of dietary vitamin C intake and the relation with bone mineral density (BMD) have been conflicting, probably because of the well-known limitations of dietary nutrient assessment questionnaires. The purpose of this study was to evaluate the independent relation of daily vitamin C supplement use with BMD in a population-based sample of postmenopausal women. Subjects were 994 women from a community-based cohort of whom 277 women were regular vitamin C supplement users. Vitamin C supplement use was validated. Daily vitamin C supplement intake ranged from 100 to 5,000 mg; the mean daily dose was 745 mg. Average duration of use was 12.4 years; 85% had taken vitamin C supplements for more than 3 years. BMD levels were measured at the ultradistal and midshaft radii, hip, and lumbar spine. After adjusting for age, body mass index (BMI), and total calcium intake, vitamin C users had BMD levels approximately 3% higher at the midshaft radius, femoral neck, and total hip (p < 0.05). In a fully adjusted model, significant differences remained at the femoral neck (p < 0.02) and marginal significance was observed at the total hip (p < 0.06). Women taking both estrogen and vitamin C had significantly higher BMD levels at all sites. Among current estrogen users, those also taking vitamin C had higher BMD levels at all sites, with marginal significance achieved at the ultradistal radius (p < 0.07), femoral neck (p < 0.07), and total hip (p < 0.09). Women who took vitamin C plus calcium and estrogen had the highest BMD at the femoral neck (p = 0.001), total hip (p = 0.05), ultradistal radius (p = 0.02), and lumbar spine. Vitamin C supplement use appears to have a beneficial effect on levels of BMD, especially among postmenopausal women using concurrent estrogen therapy and calcium supplements.
众所周知，维生素C可刺激前胶原，增强胶原蛋白合成，并刺激碱性磷酸酶活性（成骨细胞形成的标志物）。关于膳食维生素C摄入量及其与骨密度（BMD）关系的研究结果一直存在矛盾，这可能是由于膳食营养素评估问卷存在众所周知的局限性。本研究的目的是在以人群为基础的绝经后女性样本中，评估每日使用维生素C补充剂与骨密度之间的独立关系。研究对象为来自社区队列的994名女性，其中277名女性经常使用维生素C补充剂。维生素C补充剂的使用情况得到了验证。每日维生素C补充剂摄入量为100至5000毫克；平均每日剂量为745毫克。平均使用时长为12.4年；85%的人服用维生素C补充剂超过3年。在尺骨远侧端、骨干中部、髋部和腰椎测量骨密度水平。在调整年龄、体重指数（BMI）和总钙摄入量后，使用维生素C补充剂的人在骨干中部、股骨颈和全髋部的骨密度水平大约高3%（p<0.05）。在完全调整模型中，股骨颈仍存在显著差异（p<0.02），全髋部观察到边缘显著性（p<0.06）。同时服用雌激素和维生素C的女性在所有部位的骨密度水平均显著更高。在目前使用雌激素的女性中，同时服用维生素C的女性在所有部位的骨密度水平均更高，在尺骨远侧端（p<0.07）、股骨颈（p<0.07）和全髋部（p<0.09）达到边缘显著性。同时服用维生素C、钙和雌激素的女性在股骨颈（p=0.001）、全髋部（p=0.05）、尺骨远侧端（p=0.02）和腰椎的骨密度最高。使用维生素C补充剂似乎对骨密度水平有有益影响，尤其是在同时使用雌激素疗法和钙补充剂的绝经后女性中。
