Vitamin D properties, sources and biological activities

Abstract

This study provides a comprehensive review of the stages of vitamin D discovery, its properties, and natural sources, with a focus on its presence in animal, plant, algae, and fungal foods. It also emphasizes its synthesis and metabolic pathways in different organisms, including sterol pathways in animals, fungi, and plants. Notably, discoveries have identified the concentration of vitamin D3 and its receptors in several plant species, challenging the old assumption that vitamin D3 was exclusive to animals. Ultraviolet rays are the primary natural trigger of vitamin D synthesis. However, factors such as geographic location, seasonal changes, and limited sun exposure have contributed to the widespread deficiency of its levels among people worldwide. Vitamin D is a vital nutrient responsible for maintaining the balance of calcium and phosphorus in the body. It plays a crucial role in skeletal health and immune regulation, especially since it has a role against oxidation and inflammation, thereby preventing many chronic diseases such as hypertension, diabetes, heart diseases, obesity, and some types of cancer. Due to the great importance of vitamin D, studies have focused on treating its deficiency by finding natural alternatives, through the consumption of foods rich in it, whether animal or plant-based, UV-exposed mushrooms, microalgae, and fortified foods.