High-Dose Vitamin D May Help Direct Calories Toward Muscle Instead of Fat, Study Suggests

A new study published in The Journal of Physiology is shining light on another powerful benefit of the “sunshine vitamin” (Zhang et al., 2025). As reported by Men’s Health (Tracey, 2025), the research reveals vitamin D may also influence how your body uses and stores calories, specifically encouraging muscle growth over fat storage.

According to the findings published in March, high doses of vitamin D could help shift the body’s calorie allocation process. Researchers propose a new model involving two key signaling molecules: leptin and myostatin. Leptin, which is produced by fat cells, signals fullness, while myostatin, made by muscle, restricts muscle growth. The study suggests that vitamin D may modulate these signals, potentially promoting lean muscle development instead of fat accumulation when excess calories are consumed.

This discovery offers intriguing implications for fitness, metabolism, and body composition — and it’s one more reason to embrace responsible sun exposure and vitamin D support year-round.

Click here to read the article from Men’s Health.

SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can’t say in your tanning salon business.