Abstract:25-Hydroxyvitamin D3 (25-hydroxyvitamin D3,25(OH)VD3) is recognized as the primary active metabolite of vitamin D3 (VD3) in humans and animals. Compared with VD3, higher physiological potency is exhibited, and the metabolic burden on the liver is significantly reduced, making it regarded as an important food and feed additive with growing market demand. At present, 25(OH)VD3 is primarily produced on a small scale through chemical derivatization using sterols isolated from natural raw materials. However, several limitations are associated with this production process, including restricted raw material sources, the high cost of natural sterol separation and purification, and low overall yield due to the numerous chemical synthesis steps involved. With the rapid advancement of synthetic biology, various promising technologies have been developed, including the biotransformation of intermediates in the VD3 synthetic pathway and even one-step production from glucose using engineered yeast. In this review, the advantages and disadvantages of total or semi-synthesis methods were introduced first, followed by a summary of the biotransformation of 25(OH)VD3 from VD3, and a detailed discussion is provided on the latest advances in the biosynthesis of 25(OH)VD3 from glucose using engineered yeast. It is expected that this work will facilitate the exploration of promising industrial strategies for 25(OH)VD3 in the future.
