Effects of Vitamin D Supplementation on Overload‐Induced Muscle Growth and Function in Mice

• Published in: The FASEB journal 2022-05, Vol.36 (S1), p.n/a
• Main Authors: Huey, Kimberly, Conroy, Zachary, Temperly, McKenzie
• Format: Article
• Language: English
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.2022.36.S1.R2014

Muscle hypertrophy induced by functional overload (FO) provides an in vivo model to study muscle growth. Research suggests vitamin D supplementation may stimulate muscle growth and may be associated with increased growth factor levels, such as insulin‐like growth factor‐1 (IGF‐1), fibroblast growth factor (FGF), and vascular endothelial growth factor (VEGF). However, it is unclear if vitamin D impacts both muscle hypertrophy and contractile function. We hypothesized that vitamin D supplementation would positively impact the muscle response to a growth stimulus as evidenced by greater hypertrophy, increased IGF‐1, FGF, and VEGF levels, and improved contractile function compared to placebo. Adult mice underwent functional overload (FO) of the plantaris or sham surgery. In vivo plantaris force and fatigue resistance (% of maximal force after 10 contractions) were measured 14d post‐FO or sham in mice receiving daily vitamin D or placebo (n= 8‐10/group). IGF‐1, FGF, and VEGF were measured in the plantaris by ELISA. FO increased plantaris mass, independent of treatment (placebo: 22.8±1.7 vs. 13.4±1.3 and vitamin D: 20.3±3.3 vs. 13.2±0.7 mg, for FO and sham, respectively, p