Connors Center for Women's Health and Gender Biology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
Am J Clin Nutr. 2011 Aug;94(2):578-84. doi: 10.3945/ajcn.110.008771. Epub 2011 Jun 22.
The optimal public health strategy for maintaining 25-hydroxyvitamin D [25(OH)D] concentrations in schoolchildren in Mongolia is unknown.
The objective was to compare the effectiveness of different supplement and fortified milk regimens to increase 25(OH)D concentrations in Mongolian schoolchildren.
Twenty-one classrooms of 579 children aged 9-11 y were randomized to interventions with an equivalent content of vitamin D(3): 1) a one-time seasonal supplement of 13,700 IU, 2) 300 IU/d from supplements, 3) 300 IU/d from fortified ultra-high-temperature pasteurized milk from the United States, 4) 300 IU/d from fortified pasteurized Mongolian milk, or 5) unfortified pasteurized Mongolian milk (control).
In January, the mean (±SD) serum 25(OH)D concentration was 8 ± 4 ng/mL (20 ± 10 nmol/L), and 98% of the children had a concentration <20 ng/mL (50 nmol/L). In March, concentrations were 8 ± 4 ng/mL after unfortified milk, 20 ± 6 ng/mL after fortified Mongolian milk, 29 ± 10 ng/mL after fortified US milk, 21 ± 6 ng/mL after daily supplements, and 12 ± 4 ng/mL after seasonal supplements (each greater than unfortified milk, P < 0.01). Seasonal supplementation was less effective than was daily supplementation (P < 0.0001). Despite consuming daily supplements or fortified milk, 41% of the children still had concentrations <20 ng/mL (50 nmol/L). Children with lower baseline 25(OH)D concentrations experienced slightly larger 25(OH)D responses to intervention than did children with higher concentrations (P = 0.002).
In this population with extremely low vitamin D concentrations, delivery of 300 IU vitamin D/d via supplements or in fortified milk improved 25(OH)D concentrations but failed to raise concentrations uniformly to >20 ng/mL (50 nmol/L). The daily low-dose intervention was superior to the seasonal larger-dose intervention. Higher doses may be needed to prevent deficiency in schoolchildren in Mongolia and at other northern latitudes. This trial is registered at clinicaltrials.gov as NCT00886379.
维持蒙古学童 25-羟维生素 D [25(OH)D] 浓度的最佳公共卫生策略尚不清楚。
比较不同补充剂和强化牛奶方案对增加蒙古学童 25(OH)D 浓度的效果。
将 21 间教室的 579 名 9-11 岁儿童随机分为干预组，各组的维生素 D(3)含量相同：1) 一次性补充 13700 IU 季节性补充剂，2) 每日补充 300 IU 补充剂，3) 每日补充 300 IU 来自美国的超高温巴氏消毒强化牛奶，4) 每日补充 300 IU 来自蒙古巴氏消毒强化牛奶，或 5) 未强化的巴氏消毒蒙古牛奶（对照）。
1 月时，血清 25(OH)D 浓度的均值（±标准差）为 8 ± 4ng/ml（20 ± 10nmol/L），98%的儿童浓度＜20ng/ml（50nmol/L）。3 月时，未强化牛奶组浓度为 8 ± 4ng/ml，强化蒙古牛奶组为 20 ± 6ng/ml，强化美国牛奶组为 29 ± 10ng/ml，每日补充剂组为 21 ± 6ng/ml，季节性补充剂组为 12 ± 4ng/ml（均高于未强化牛奶，P＜0.01）。季节性补充不如每日补充有效（P＜0.0001）。尽管儿童每日补充或饮用强化牛奶，但仍有 41%的儿童浓度＜20ng/ml（50nmol/L）。基线 25(OH)D 浓度较低的儿童对干预的 25(OH)D 反应略大于浓度较高的儿童（P=0.002）。
在 25(OH)D 浓度极低的人群中，每日 300IU 维生素 D 通过补充剂或强化牛奶摄入可提高 25(OH)D 浓度，但未能将浓度普遍提高到＞20ng/ml（50nmol/L）。每日低剂量干预优于季节性大剂量干预。在蒙古和其他高纬度地区，可能需要更高的剂量来预防儿童维生素 D 缺乏症。该试验在 clinicaltrials.gov 上注册为 NCT00886379。
