The role of vitamin D deficiency in the development of paediatric diseases

Figures & data

Figure 1. VitD metabolism. The synthesis of VitD3 in the skin is triggered by ultraviolet radiation (UVR) or by food consumption. By combining with VitD-binding protein (VDBP), VitD3 is transported into the liver. Cytochrome P-450 enzymes (CYP2R1 and CYP27A) are responsible for converting VitD3 to 25-hydroxyVitD (25(OH)D₃) in the liver. The 25(OH)D₃ is converted into 1,25-dihydroxyVitD3 (1,25-(OH)₂D₃) in the kidneys, liver, lungs, brain, intestines and heart by 1α-hydroxylase.

Figure 2. ASD children’s behaviours may be affected by VitD regulating the secretion of dopamine and serotonin/melatonin. DVD: development VitD; DA: dopamine neurons.

Figure 3. Calcium is absorbed in the proximal intestine and transported to bones via paracellular transport and transcellular transport. VDR: VitD receptor; TRPV6: transient receptor potential vanilloid type 6; NCX1: Na⁺-Ca²⁺ exchanger 1.

Data availability statement

Data sharing is not applicable to this article as no new data were created or analysed in this study.