Whey protein, with or without vitamin D, for muscle in older adults
What it found
In older adults, whey protein on its own did not change lean mass or muscle strength overall, but it did improve physical function.
Adding vitamin D improved lean mass, strength and function.
What they found
Studies in people
Lean mass overall
Across all trials, whey protein supplementation had no significant effect on lean mass. In a subgroup of older adults who were sarcopenic or frail, lean mass improved.
Muscle strength
Whey protein alone did not change muscle strength overall. Strength improved in subgroups where both groups did resistance exercise and where whey protein doses were higher than 20 g.
Physical function
Whey protein supplementation improved physical function, particularly gait speed. This was seen in sarcopenic or frail participants, without resistance exercise, with doses lower than 20 g, and in studies longer than 12 weeks.
Whey plus vitamin D
Co-supplementation with whey protein and vitamin D improved lean mass, muscle strength and physical function. These effects were seen without resistance exercise and in studies lasting 12 weeks or less.
Resistance exercise
When both groups did resistance exercise, adding whey protein plus vitamin D did not enhance the effect of the exercise. The authors say the exercise effect likely overshadowed any supplement effect.
Other findings
Quality of evidence
The authors rated the quality of evidence as low or very low for most outcomes. Heterogeneity was high across studies.
What the authors conclude
“Whey protein supplementation improved LM and function in sarcopenic/frail older adults but had no positive effect in healthy older persons.”
Also in their conclusions
- They conclude that whey protein supplementation improved lean mass and function in sarcopenic or frail older adults but had no positive effect in healthy older persons.
- They state that co-supplementation with whey protein and vitamin D is effective, particularly in healthy older adults, likely due to correcting vitamin D insufficiency or deficiency.
- They call for further studies to better elucidate the exact mechanisms of action of vitamin D combined with whey protein on sarcopenia measures and muscle protein anabolism.
How it was done
The authors say it is unclear whether whey protein alone or with vitamin D helps sarcopenia-related outcomes in older adults. Guidelines suggest resistance exercise, protein and vitamin D, but the best combination is not clear.
They pooled 30 randomised controlled trials in people aged 60 or older, published between 2012 and 2022. Twenty-two trials tested whey protein alone and 8 tested whey protein plus vitamin D. Doses ranged from 15 to 40 g per day for whey protein and 100 to 800 IU for vitamin D, and studies lasted from 12 weeks to 2 years and 8 weeks.
What it can’t tell you
- The evidence quality was low or very low, so the findings need to be interpreted with caution.
- The studies used different ways to measure muscle mass, strength and function, which makes comparisons unclear.
- Subgroup analyses sometimes included few studies and small populations, so those results are less certain.
Who paid
- Funding
- Funded by CIHR (from the PubMed record).
- Authors work at
- Shiraz University of Medical Sciences, Iran; McMaster University, Canada; Federal University of Santa Catarina, Brazil
The paper
- Title
- Whey Protein Supplementation with or without Vitamin D on Sarcopenia-Related Measures: A Systematic Review and Meta-Analysis
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Nasimi N, Sohrabi Z, Nunes EA, et al (2023). Whey Protein Supplementation with or without Vitamin D on Sarcopenia-Related Measures: A Systematic Review and Meta-Analysis. Advances in nutrition (Bethesda, Md.). doi:10.1016/j.advnut.2023.05.011Free full textPubMed 37196876DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error