The Claim

Twelve weeks of progressive resistance training significantly increases quadriceps muscle cross-sectional area and isometric strength in both healthy young and elderly men, while vitamin D supplementation provides no additional benefit to these primary outcomes.

Source: Does vitamin-D intake during resistance training improve the skeletal muscle hypertrophic and strength response in young and elderly men? – a randomized controlled trial

What the research says

Supports is higher

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

Supports
53score
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

Doing strength training for 12 weeks can make your thigh muscles bigger and stronger, whether you're young or old—but taking vitamin D pills won’t make that improvement any better.

See the scientific wording

Twelve weeks of progressive resistance training significantly increases quadriceps muscle cross-sectional area and isometric strength in both healthy young and elderly men, but vitamin D supplementation provides no additional benefit to these primary outcomes.

What the research says

1 study

  1. Study: Does vitamin-D intake during resistance training improve the skeletal muscle hypertrophic and strength response in young and elderly men? – a randomized controlled trial

    The study found that lifting weights made both young and old men’s thigh muscles bigger and stronger, but taking vitamin D pills didn’t make them any bigger or stronger than just taking a placebo pill.

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.