The Claim

In vitamin D-deficient young males, six weeks of resistance training combined with daily supplementation of 25 grams of whey protein and 4000 IU of vitamin D3 causes significant increases in serum vitamin D levels, with average increases ranging from 5.7 to 11.9 ng/mL, resulting in most participants achieving sufficient vitamin D status.

Source: Muscle-Related Effect of Whey Protein and Vitamin D3 Supplementation Provided before or after Bedtime in Males Undergoing Resistance Training

What the research says

Supports is higher

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

Supports
54score
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

If young guys who don’t have enough vitamin D take 4000 IU of vitamin D and 25 grams of whey protein every day while doing strength training for six weeks, their vitamin D levels go up enough to get into a healthy range.

See the scientific wording

Six weeks of resistance training combined with 25 grams of whey protein and 4000 IU of vitamin D3 daily causes significant increases in serum vitamin D levels in vitamin D-deficient young males, with average increases of 5.7–11.9 ng/mL, bringing most participants into sufficient range.

What the research says

1 study
  1. Study: Muscle-Related Effect of Whey Protein and Vitamin D3 Supplementation Provided before or after Bedtime in Males Undergoing Resistance Training

    The study gave young men whey protein and vitamin D every day for six weeks while they did strength training, and their vitamin D levels went up—just like the claim says.

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.