Melhus H, Michaëlsson K, Kindmark A, Bergström R, Holmberg L, Mallmin H, Wolk A, Ljunghall S
University Hospital, Uppsala, Sweden.
Ann Intern Med. 1998 Nov 15;129(10):770-8. doi: 10.7326/0003-4819-129-10-199811150-00003.
The highest incidence of osteoporotic fractures is found in northern Europe, where dietary intake of vitamin A (retinol) is unusually high. In animals, the most common adverse effect of toxic doses of retinol is spontaneous fracture.
To investigate whether excessive dietary intake of vitamin A is associated with decreased bone mineral density and increased risk for hip fracture.
A cross-sectional study and a nested case-control study.
Two counties in central Sweden.
For the cross-sectional study, 175 women 28 to 74 years of age were randomly selected. For the nested case-control study, 247 women who had a first hip fracture within 2 to 64 months after enrollment and 873 age-matched controls were selected from a mammography study cohort of 66,651 women 40 to 76 years of age.
Retinol intake was estimated from dietary records and a food-frequency questionnaire. Bone mineral density was measured with dual-energy x-ray absorptiometry. Hip fracture was identified by using hospital discharge records and was confirmed by record review.
In multivariate analysis, retinol intake was negatively associated with bone mineral density. For every 1-mg increase in daily intake of retinol, risk for hip fracture increased by 68% (95% CI, 18% to 140%; P for trend, 0.006). For intake greater than 1.5 mg/d compared with intake less than 0.5 mg/d, bone mineral density was reduced by 10% at the femoral neck (P = 0.05), 14% at the lumbar spine (P = 0.001), and 6% for the total body (P = 0.009) and risk for hip fracture was doubled (odds ratio, 2.1 [CI, 1.1 to 4.0]).
High dietary intake of retinol seems to be associated with osteoporosis.
骨质疏松性骨折的最高发病率出现在北欧，那里维生素A（视黄醇）的膳食摄入量异常高。在动物中，毒性剂量视黄醇最常见的不良反应是自发性骨折。
调查膳食中维生素A摄入过量是否与骨矿物质密度降低及髋部骨折风险增加有关。
一项横断面研究和一项巢式病例对照研究。
瑞典中部的两个县。
横断面研究随机选取了175名年龄在28至74岁的女性。巢式病例对照研究从一项针对66651名年龄在40至76岁女性的乳房X线摄影研究队列中，选取了247名在入组后2至64个月内首次发生髋部骨折的女性以及873名年龄匹配的对照者。
通过饮食记录和食物频率问卷估算视黄醇摄入量。采用双能X线吸收法测量骨矿物质密度。通过医院出院记录确定髋部骨折，并经记录复查确认。
在多变量分析中，视黄醇摄入量与骨矿物质密度呈负相关。视黄醇每日摄入量每增加1毫克，髋部骨折风险增加68%（95%可信区间为18%至140%；趋势P值为0.006）。与摄入量低于0.5毫克/天相比，摄入量大于1.5毫克/天时，股骨颈骨矿物质密度降低10%（P = 0.05），腰椎降低14%（P = 0.001），全身降低6%（P = 0.009），髋部骨折风险翻倍（比值比为2.1 [可信区间为1.1至4.0]）。
膳食中视黄醇摄入量高似乎与骨质疏松症有关。
