學生姓名:
徐苡宸
指導教授:
張君如
學期:
114下
摘 要:
Sarcopenia is a condition associated with aging, lifestyle changes, and chronic diseases, characterized by a progressive decline in muscle mass. Vitamin D supplementation activates the vitamin D receptor (VDR) and its downstream signaling pathways, thereby promoting muscle cell differentiation, enhancing muscle protein synthesis, and preserving muscle mass. Talib et al. (2023) investigated the effects of vitamin D3 and VDR on muscle synthesis and degradation signaling pathways in relation to muscle health. After four days of differentiation in mouse C2C12 cell lines, treatment with vitamin D3 (0, 1, 10, 100, or 200 nM) for 24 hours upregulated the expression of VDR and SIRT1/3 proteins, activated the energy metabolism signaling pathway (AMPK/AKT), and promoted the expression of muscle differentiation related proteins (MyHC I/II, MyoD/G, etc.). Subsequently, IFN-γ and TNF-α induced inflammation in muscle cells, leading to atrophy and apoptosis, along with reduced VDR expression, diminished downstream signaling factors, and decreased mitochondrial DNA copy number and complex mRNA expression. Vitamin D3 supplementation alleviated these inflammatory effects. In a clinical trial by Kawahara et al. (2025), 32 participants were
randomly assigned to either a placebo group or a treatment group receiving Eldecalcitol (an active vitamin D analog) at 0.75 μg/day. Muscle samples from the vastus lateralis were collected and analyzed after one year. Compared to the placebo group, the treatment group exhibited increased phosphorylation of AMPK/AKT, cellular translation factors (mTOR/FOXO, p70S6K1, rpS6, 4E-BP1, and eIF-4E) in muscle tissue, and upregulated expression of the muscle metabolism factor MuRF1. No significant differences were observed in BMI or waist circumference between groups; however, the treatment group showed significant improvements in lean body mass and muscle mass, reduced fat mass, and increased grip strength. In summary, vitamin D supplementation activates key signaling factors such as VDR, SIRT1/3, mTOR, and AMPK/AKT, enhances mitochondrial function, improves muscle quality and strength, and may help mitigate muscle inflammation and sarcopenia.
徐苡宸.pdf