School of Human Nutrition, McGill University, Ste-Anne-de-Bellevue, Quebec, Canada.
Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
Am J Clin Nutr. 2018 Mar 1;107(3):355-364. doi: 10.1093/ajcn/nqx062.
Most Canadian children do not meet the recommended dietary intake for vitamin D.
The aims were to test how much vitamin D from food is needed to maintain a healthy serum 25-hydroxyvitamin D3 [25(OH)D3] status from fall to spring in young children and to examine musculoskeletal outcomes.
Healthy children aged 2-8 y (n = 51) living in Montreal, Canada, were randomly assigned to 1 of 2 dietary vitamin D groups (control or intervention to reach 400 IU/d by using vitamin D-fortified foods) for 6 mo, starting October 2014. At baseline and at 3 and 6 mo, anthropometric characteristics, vitamin D metabolites (liquid chromatography-tandem mass spectrometry), and bone biomarkers (IDS-iSYS, Immunodiagnositc Systems; Liaison; Diasorin) were measured and physical activity and food intakes surveyed. At baseline and at 6 mo, bone outcomes and body composition (dual-energy X-ray absorptiometry) were measured. Cross-sectional images of distal tibia geometry and muscle density were conducted with the use of peripheral quantitative computed tomography scans at 6 mo.
At baseline, participants were aged 5.2 ± 1.9 (mean ± SD) y and had a body mass index z score of 0.65 ± 0.12; 53% of participants were boys. There were no differences between groups in baseline serum 25(OH)D3 (66.4 ± 13.6 nmol/L) or vitamin D intake (225 ± 74 IU/d). Median (IQR) compliance was 96% (89-99%) for yogurt and 84% (71-97%) for cheese. At 3 mo, serum 25(OH)D3 was higher in the intervention group (P < 0.05) but was not different between groups by 6 mo. Although lean mass accretion was higher in the intervention group (P < 0.05), no differences in muscle density or bone outcomes were observed.
The consumption of 400 IU vitamin D/d from fall to spring did not maintain serum 25(OH)D3 concentration or improve bone outcomes. Further work with lean mass accretion as the primary outcome is needed to confirm if vitamin D enhances lean accretion in healthy young children. This trial was registered at www.clinicaltrials.gov as NCT02387892.
大多数加拿大儿童的维生素 D 摄入量达不到推荐标准。
本研究旨在测试儿童从食物中摄取多少维生素 D 才能在秋季到春季维持健康的血清 25-羟维生素 D3 [25(OH)D3]水平，并观察其对骨骼肌肉的影响。
2014 年 10 月，51 名年龄在 2-8 岁的健康儿童（居住在加拿大蒙特利尔）被随机分配到 2 个饮食维生素 D 组（对照组或干预组，通过食用添加维生素 D 的食物将维生素 D 摄入量增加到 400IU/d），干预时长为 6 个月。在基线和 3 个月及 6 个月时，测量了儿童的人体测量特征、维生素 D 代谢物（液相色谱-串联质谱法）和骨生物标志物（IDS-iSYS、Immunodiagnositc Systems；Liaison；Diasorin），并调查了儿童的身体活动和食物摄入量。在基线和 6 个月时，还测量了儿童的骨骼健康状况和身体成分（双能 X 射线吸收法）。在 6 个月时，利用外周定量计算机断层扫描技术对儿童的胫骨远端几何形状和肌肉密度进行了横截面图像分析。
基线时，参与者的年龄为 5.2±1.9（均值±标准差）岁，体重指数 z 评分 0.65±0.12；53%的参与者为男性。两组儿童的基线血清 25(OH)D3 水平（66.4±13.6 nmol/L）或维生素 D 摄入量（225±74IU/d）均无差异。酸奶和奶酪的平均（IQR）依从率分别为 96%（89-99%）和 84%（71-97%）。在 3 个月时，干预组的血清 25(OH)D3 水平较高（P<0.05），但到 6 个月时两组间无差异。干预组的瘦体重增加较多（P<0.05），但肌肉密度或骨骼健康状况无差异。
在秋季到春季期间，每天摄入 400IU 维生素 D 并不能维持血清 25(OH)D3 浓度或改善骨骼健康状况。需要进一步研究以确认维生素 D 是否能增加健康幼儿的瘦体重。本试验已在 www.clinicaltrials.gov 上注册，编号为 NCT02387892。
