Cashman Kevin D, Kazantzidis Andreas, Webb Ann R, Kiely Mairead
Vitamin D Research Group, School of Food and Nutritional Science, and Department of Medicine, University College Cork, Cork, Ireland;
School of Earth Atmospheric and Environmental Sciences, University of Manchester, Manchester, United Kingdom; and Laboratory of Atmospheric Physics, Physics Department, University of Patras, Patras, Greece.
J Nutr. 2015 Oct;145(10):2419-25. doi: 10.3945/jn.115.217968. Epub 2015 Aug 19.
To enable food-based strategies for the prevention of vitamin D deficiency to be evidence-based, there is a need to develop integrated predictive models of population serum 25-hydroxyvitamin D [25(OH)D] that are responsive to both solar and dietary inputs of vitamin D.
The objectives of this work were to develop and validate an integrated mathematical model with the use of data on UVB availability, exposure, and dietary intake to predict serum 25(OH)D concentrations in a nationally representative sample of adults, and then test the model's performance with the use of 3 hypothetical fortification scenarios as exemplars.
Data on UVB availability and hours of sunlight in Ireland were used in a mathematical model to predict serum 25(OH)D in Irish adults aged 18-64 y. An equation from our dose-related vitamin D supplementation trial in adults was developed and integrated into the model, which allowed us to predict the impact of changes in dietary vitamin D on the contribution to annual serum 25(OH)D concentrations, accounting for seasonality of UVB availability. Recently published estimates of the impact of 3 vitamin D food fortification scenarios on vitamin D intake in a representative sample of Irish adults were used in the model as a test.
The UVB- and vitamin D intake-serum 25(OH)D components of the integrated model were both validated with the use of independent data. The model predicted that the percentage of vitamin D deficiency [serum 25(OH)D <30 nmol/L] in the adult population during an extended winter period was 18.1% (vs. 18.6% measured), which could be reduced in a stepwise manner with the incorporation of an increased number of vitamin D-fortified foods, down to 6.6% with the inclusion of enhanced fortified dairy-related products, fat spreads, fruit juice and drinks, and cereal products.
Mathematical models have the ability to inform how vitamin D food fortification in various constructs may affect population serum 25(OH)D concentrations and the prevalence of vitamin D deficiency.
为使基于食物的维生素D缺乏预防策略有证据支持，需要建立综合预测模型，以反映人群血清25-羟基维生素D[25(OH)D]水平，该模型需对维生素D的日照和膳食摄入情况均做出响应。
本研究旨在利用紫外线B（UVB）可获得性、暴露情况及膳食摄入数据，建立并验证一个综合数学模型，用于预测具有全国代表性的成年人群血清25(OH)D浓度，随后以3种假设的强化方案为例，测试该模型的性能。
将爱尔兰UVB可获得性及日照时长数据用于数学模型，以预测18至64岁爱尔兰成年人的血清25(OH)D水平。基于我们在成年人中进行的剂量相关维生素D补充试验得出的一个方程式被开发出来并整合到模型中，该方程式使我们能够预测膳食维生素D变化对年度血清25(OH)D浓度贡献的影响，并考虑到UVB可获得性的季节性。最近发表的对3种维生素D食物强化方案对爱尔兰成年代表性样本维生素D摄入量影响的估计值被用于模型测试。
综合模型中UVB及维生素D摄入-血清25(OH)D各组成部分均通过独立数据得到验证。该模型预测，在漫长冬季期间成年人群中维生素D缺乏[血清25(OH)D<30nmol/L]的比例为18.1%（实测值为18.6%），随着添加越来越多的维生素D强化食品，这一比例可逐步降低，若纳入强化乳制品相关产品、涂抹脂肪、果汁饮料及谷物产品，比例可降至6.6%。
数学模型能够说明不同结构的维生素D食物强化如何影响人群血清25(OH)D浓度及维生素D缺乏的患病率。
