The Claim

Daily supplementation with 8000 IU of vitamin D for 12 weeks has no enhancing effect on chest press and seated row strength gains during resistance training in vitamin D-deficient young men and may result in reduced strength gains compared to a placebo.

Source: Vitamin D supplementation does not enhance resistance training-induced gains in muscle strength and lean body mass in vitamin D deficient young men

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
47score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

Taking a high-dose vitamin D pill every day for three months won't help young men who are low on vitamin D get stronger from weight training—and might even make them weaker compared to those who take a sugar pill.

See the scientific wording

Vitamin D supplementation at 8000 IU daily for 12 weeks does not enhance chest press and seated row strength gains during resistance training in vitamin D-deficient young men, and may even impair them compared to placebo.

What the research says

1 study
  1. Study: Vitamin D supplementation does not enhance resistance training-induced gains in muscle strength and lean body mass in vitamin D deficient young men

    The study gave young men with low vitamin D either a high-dose supplement or a sugar pill while they lifted weights. The ones who took the vitamin D didn’t get stronger in chest press and seated row as much as those who took the placebo—so the supplement didn’t help and might have made things worse.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.