The community is debating the idea that massive vitamin D supplementation could promote muscle gain at the expense of fat by modifying certain hormonal signals related to metabolism.

noli's read

The community is deeply divided, if not alarmed, by the extreme doses mentioned, largely rejecting the idea of such intake without supervision. Scientifically, although vitamin D plays a role in muscle function and hormonal regulation, the claim that it would redirect calories to muscle via myostatin or leptin remains speculative. Systematic reviews (e.g., meta-analyses on supplementation and performance) indicate that while a deficiency impairs muscle function, an excess offers no proven 'caloric redirection' benefit in humans. Observational studies show correlations between blood levels and body composition, but do not demonstrate any causal link regarding nutrient partitioning. The idea of metabolic manipulation through high doses is therefore an exaggerated extrapolation of known biological functions. Furthermore, excessive intake carries well-documented risks of toxicity (advice from health authorities).

the sources

1. 1r/AdvancedFitness