A recent study published in Frontiers in Nutrition explored how Vital Proteins collagen peptide (CP) supplementation affects premenopausal female endurance athletes. This group faces unique hormonal fluctuations and an increased risk of low energy availability, factors that can notably influence bone health and inflammation levels.
“These factors create a distinct physiological environment in which osteoblast and osteoclast activity, as well as cytokine dynamics, may respond differently to nutritional interventions compared to other populations,” stated researchers from Fitchburg State University and the University of Connecticut.
The study found that short-term CP supplementation led to an increase in a bone formation marker, modified osteoclast signaling pathways, and a decrease in interleukin-6 (IL-6), an inflammatory cytokine associated with a reduced risk of cardiovascular issues.
“These findings support the potential for CP-mediated modulation of bone turnover and inflammatory activity and suggest the need for further investigation in larger, well-designed trials that include structural bone outcomes,” the report noted.
Bone Metabolism in Female Distance Runners
According to the researchers, female distance runners are particularly vulnerable to impaired bone remodeling due to high mechanical stress, potential low energy availability, and chronic inflammatory conditions.
Collagen peptide supplementation has been proposed as a nutritional strategy aimed at enhancing type I collagen synthesis and modulating osteoimmune responses, alongside typical supplements like protein, calcium, and vitamin D.
Derived from enzymatically hydrolyzed type I collagen, collagen peptides (CPs) are gaining attention as a promising complementary approach. Rich in glycine, proline, and hydroxyproline, these peptides can be absorbed as bioactive di- and tripeptides, potentially stimulating osteoblast function and promoting extracellular matrix synthesis.
Despite their potential, research on CPs in premenopausal women remains limited, with most studies focusing on men or postmenopausal females.
The Study
In this randomized, double-blind, placebo-controlled trial, 22 active female participants aged 18 to 35, who averaged over 35 miles of running per week, were assigned to receive either 20g of CP (Vital Proteins) or a placebo daily, consumed within one hour of waking.
Participants used the MyFitnessPal app to log their dietary intake, including total calories and macronutrients. Exercise-induced energy expenditure was monitored via heart rate monitors during workouts and competitions to accurately determine energy availability (EA).
Pre- and post-intervention assessments were conducted in the early follicular phase of the participants’ menstrual cycles to minimize variability in bone turnover markers (BTMs) associated with hormone fluctuations.
These assessments included serum procollagen type I N-terminal propeptide (P1NP), plasma C-terminal telopeptide of type I collagen (CTX-1), serum soluble receptor activator of nuclear factor-κB ligand (sRANKL), osteoprotegerin (OPG), the sRANKL/OPG ratio, and interleukin-6 (IL-6). Researchers performed repeated-measures ANCOVAs, adjusting for total running distance and vitamin D levels.
The results demonstrated that collagen supplementation elevated levels of serum procollagen type I N-terminal propeptide (P1NP), indicating increased bone formation, without affecting C-terminal telopeptide of type I collagen (CTX-1), a marker of bone resorption. Additionally, the sRANKL/OPG ratio, a significant marker of bone metabolism and vascular health, remained stable, accompanied by a decrease in circulating IL-6 levels.
“Together, these findings substantiate the plausibility that CPs may influence osteoblast activity and immune regulation in a population exposed to repetitive mechanical stress,” remarked the report.
Although the study was constrained by its small sample size, brief duration, and lack of imaging outcomes, the observed effects were significant enough to warrant further research.
“Future larger, long-term studies that integrate structural bone assessments and additional mechanistic biomarkers are essential to ascertain whether these initial biochemical changes lead to meaningful skeletal adaptations and reduced injury risks among female endurance athletes,” the report concluded.
Source: Frontiers in Nutrition, doi: 10.3389/fnut.2026.1825906, “Effects of collagen peptide supplementation on bone turnover, cytokine, and inflammatory markers in female distance runners: a randomized pilot study”, Authors: Kuhlman, N.M. et al
