National Institute of Nutrition and Health, Chinese Center for Disease Control and Prevention, 29 Nan Wei Road, Xi Cheng District, Beijing, 100050, China.
Osteoporos Int. 2019 Nov;30(11):2231-2239. doi: 10.1007/s00198-019-05105-4. Epub 2019 Aug 2.
The study is to determine the effects of milk powder on bone density and metabolism in healthy adolescents. Vitamin D and calcium supplements increased IGF-1 but did not affect bone mineralization or turnover. Higher vitamin D in combination with sufficient calcium supplementation in such populations requires attention.
Both calcium and vitamin D play an important role in bone mineralization in adolescents.
In this one and a half-year randomized controlled trial, 232 participants (aged 12-15 years) were randomly assigned to three intervention groups receiving milk powder fortified with vitamin D 400 IU plus calcium 300, or 600, or 900 mg [Ca3D (n = 54), Ca6D (n = 56), and Ca9D (n = 49)], or one control group maintaining habitual diet [control (n = 73)]. Bone turnover markers, serum intact PTH, 25(OH)D, and IGF-1 levels were measured at baseline and one and a half years, and bone mineral contents and bone areal mineral density were measured by Dual-energy X-ray absorptiometry (DXA) at baseline, one year, and one and a half years.
Baseline average serum 25(OH)D level and calcium intake were 29.4 nmol/L and 363.5 mg/day, respectively. There was a significant increase in bone turnover, total body, hip, lumbar spine bone mineral density (BMD), and total body BMC as well as slight fluctuations in 25(OH)D levels over one and a half years without between-group differences. Significantly decreased serum PTH level was only observed in the Ca6D group (31%, p < 0.0001), in which the intervention effect was also significant (p = 0.0029) compared with the control group. IGF-1 levels increased significantly in all intervention groups (18.5 to 22.8%, p < 0.05) but decreased in the control group (16.5%, p < 0.05), and the group by time interaction was also significant (p = 0.0029).
Our study showed that in healthy adolescents with low vitamin D status and calcium intake, mild vitamin D and mild to modest calcium supplements increased IGF-1 but did not affect bone mineralization or turnover. Higher vitamin D in combination with sufficient calcium supplementation in such populations requires attention.
本研究旨在确定奶粉对健康青少年骨密度和代谢的影响。维生素 D 和钙补充剂增加了 IGF-1，但对骨矿化或转换没有影响。在这些人群中，需要注意更高的维生素 D 与充足的钙补充相结合。
钙和维生素 D 对青少年的骨矿化都有重要作用。
在这项为期一年半的随机对照试验中，将 232 名（年龄 12-15 岁）参与者随机分配到三个干预组，分别接受添加 400 IU 维生素 D 和 300、600 或 900 mg 钙的奶粉[Ca3D（n=54）、Ca6D（n=56）和 Ca9D（n=49）]，或一个维持习惯性饮食的对照组[控制组（n=73）]。在基线和一年半时测量骨转换标志物、血清完整甲状旁腺素、25（OH）D 和 IGF-1 水平，并在基线、一年和一年半时使用双能 X 射线吸收法（DXA）测量骨矿物质含量和骨面积骨密度。
基线平均血清 25（OH）D 水平和钙摄入量分别为 29.4 nmol/L 和 363.5 mg/天。一年半内，骨转换、全身、髋部、腰椎骨密度（BMD）和全身 BMC 均有显著增加，25（OH）D 水平略有波动，但组间无差异。仅在 Ca6D 组观察到血清 PTH 水平显著下降（31%，p<0.0001），与对照组相比，该组的干预效果也显著（p=0.0029）。所有干预组的 IGF-1 水平均显著升高（18.5 至 22.8%，p<0.05），但对照组 IGF-1 水平下降（16.5%，p<0.05），组间时间交互作用也有统计学意义（p=0.0029）。
本研究表明，在维生素 D 状态和钙摄入量低的健康青少年中，轻度维生素 D 和轻度至中度钙补充剂增加了 IGF-1，但对骨矿化或转换没有影响。在这些人群中，需要注意更高的维生素 D 与充足的钙补充相结合。
