Kamiya Kuniyasu, Kojima Akane, Tachiki Takahiro, Imai Nami, Kouda Katsuyasu, Hamada Masami, Kudo Asako, Tsuda Kouji, Hata Akiko, Ohara Kumiko, Takashima Naoyuki, Sato Yuho, Tanaka Miho, Kitagawa Jun, Uenishi Kazuhiro, Tamaki Junko, Kajita Etsuko, Kagamimori Sadanobu, Matsumoto Toshio, Iki Masayuki
Basic Medical Sciences Region, Kobe City College of Nursing, 3-4 Gakuen-Nishi-Machi, Nishi-Ku, Kobe, Japan.
Department of Nutrition, Faculty of Health and Nutrition, Yamanashi Gakuin University, Kofu, Japan.
Osteoporos Int. 2025 Jun 23. doi: 10.1007/s00198-025-07577-z.
The associations between milk intake frequency and fracture risk in groups categorized by 25(OH)D levels were investigated using 20-year follow-up data. A significant association was observed only among women with 25(OH)D levels < 15 ng/mL. The measurement of blood 25(OH)D levels should be prioritized for individuals with low milk intake.
To investigate the association between milk intake frequency and fracture risk in groups based on blood 25(OH)D levels.
This secondary analysis of a prospective cohort study included data from 1209 postmenopausal Japanese women aged ≥ 50 years. Baseline milk intake frequency was obtained using a questionnaire. Blood 25(OH)D levels were measured using a competitive protein-binding assay. Information on fracture events was obtained from face-to-face interviews through follow-up or supplemental mail surveys.
Over a median follow-up period of 16.1 years (total: 17,427 person-years), 358 and 238 women sustained at least one clinical and osteoporotic fracture, respectively. The proportions of participants with milk intake < 1 glass/day and those with 25(OH)D levels < 15 ng/mL were 31.9% and 21.6%, respectively. In univariate Cox proportional hazard analyses, a 25(OH)D level < 15 ng/mL and a milk intake of < 1 glass/day were associated with an increased risk of clinical and osteoporotic fractures. Among participants with 25(OH)D levels < 15 ng/mL, the adjusted hazard ratios for milk intake < 1 glass/day compared to ≥ 1 glass/day were 1.99 (95% confidence interval: 1.32-2.99) and 2.11 (1.28-3.47) for clinical and osteoporotic fractures, respectively. In contrast, the HRs were not significant among those with 25(OH)D levels ≥ 15 ng/mL.
A clear positive association was identified between milk intake frequency and fracture risk among Japanese women after menopause with low 25(OH)D levels. Therefore, correcting vitamin D insufficiency would likely lower fracture risk. In addition, encouraging habitual milk intake may help prevent fractures, particularly among individuals with low 25(OH)D levels.
使用20年的随访数据，研究了按25(OH)D水平分类的组中牛奶摄入频率与骨折风险之间的关联。仅在25(OH)D水平<15 ng/mL的女性中观察到显著关联。对于牛奶摄入量低的个体，应优先测量血液25(OH)D水平。
基于血液25(OH)D水平，研究组中牛奶摄入频率与骨折风险之间的关联。
这项前瞻性队列研究的二次分析纳入了1209名年龄≥50岁的绝经后日本女性的数据。使用问卷获取基线牛奶摄入频率。使用竞争性蛋白结合测定法测量血液25(OH)D水平。通过随访或补充邮件调查中的面对面访谈获取骨折事件信息。
在中位随访期16.1年（总计17427人年）内，分别有358名和238名女性发生了至少一次临床骨折和骨质疏松性骨折。牛奶摄入量<1杯/天的参与者比例和25(OH)D水平<15 ng/mL的参与者比例分别为31.9%和21.6%。在单变量Cox比例风险分析中，25(OH)D水平<15 ng/mL和牛奶摄入量<1杯/天与临床骨折和骨质疏松性骨折风险增加相关。在25(OH)D水平<15 ng/mL的参与者中，与牛奶摄入量≥1杯/天相比，牛奶摄入量<1杯/天的临床骨折和骨质疏松性骨折调整后风险比分别为1.99（95%置信区间：1.32 - 2.99）和2.11（1.28 - 3.47）。相比之下，在25(OH)D水平≥15 ng/mL的参与者中，风险比不显著。
在25(OH)D水平低的绝经后日本女性中，牛奶摄入频率与骨折风险之间存在明确的正相关。因此，纠正维生素D不足可能会降低骨折风险。此外，鼓励习惯性饮用牛奶可能有助于预防骨折，特别是在25(OH)D水平低的个体中。
