Division of Food Chemistry, National Food Institute, Technical University of Denmark Søborg, Denmark.
Front Plant Sci. 2013 May 13;4:136. doi: 10.3389/fpls.2013.00136. eCollection 2013.
The major function of vitamin D in vertebrates is maintenance of calcium homeostasis, but vitamin D insufficiency has also been linked to an increased risk of hypertension, autoimmune diseases, diabetes, and cancer. Therefore, there is a growing awareness about vitamin D as a requirement for optimal health. Vitamin D3 is synthesized in the skin by a photochemical conversion of provitamin D3, but the necessary rays are only emitted all year round in places that lie below a 35° latitude. Unfortunately, very few food sources naturally contain vitamin D and the general population as a results fail to meet the requirements. Fish have the highest natural content of vitamin D expected to derive from an accumulation in the food chain originating from microalgae. Microalgae contain both vitamin D3 and provitamin D3, which suggests that vitamin D3 exist in the plant kingdom and vitamin D3 has also been identified in several plant species as a surprise to many. The term vitamin D also includes vitamin D2 that is produced in fungi and yeasts by UVB-exposure of provitamin D2. Small amounts can be found in plants contaminated with fungi and traditionally only vitamin D2 has been considered present in plants. This review summarizes the current knowledge on sterol biosynthesis leading to provitamin D. It also addresses the occurrence of vitamin D and its hydroxylated metabolites in higher plants and in algae and discusses limitations and advantages of analytical methods used in studies of vitamin D and related compounds including recent advances in analytical technologies. Finally, perspectives for a future production of vitamin D biofortified fruits, vegetables, and fish will be presented.
维生素 D 在脊椎动物中的主要功能是维持钙稳态，但维生素 D 不足也与高血压、自身免疫性疾病、糖尿病和癌症风险增加有关。因此，人们越来越意识到维生素 D 是维持最佳健康的必需物质。维生素 D3 可通过维生素 D3 的光化学转化在皮肤中合成，但只有在纬度低于 35°的地方，全年才会有必要的射线发出。不幸的是，很少有天然食物含有维生素 D，因此大多数人无法满足其需求。鱼类的维生素 D 含量最高，这是由于食物链中的维生素 D 在食物链中积累而来，而食物链则源自微藻。微藻既含有维生素 D3，也含有维生素 D3 的前体物质，这表明维生素 D3 存在于植物界，而且在许多植物物种中也发现了维生素 D3，这让许多人感到惊讶。术语“维生素 D”还包括真菌和酵母通过暴露于 UVB 产生的维生素 D2。在受真菌污染的植物中也可以发现少量的维生素 D2，而传统上只认为植物中存在维生素 D2。本文综述了目前关于甾体生物合成导致维生素 D 前体物质形成的知识。它还讨论了维生素 D 及其羟基化代谢物在高等植物和藻类中的存在情况，并讨论了用于研究维生素 D 及其相关化合物的分析方法的局限性和优势，包括分析技术的最新进展。最后，还将介绍未来生产富含维生素 D 的水果、蔬菜和鱼类的前景。
