Establishing Dietary Reference Intakes for Creatine in Adults.
Level 5 - mechanism / opinion, no new human data
Mechanism-based reasoning and physiological modeling without new primary empirical data
PubMed 41689538 · doi:10.1093/nutrit/nuag009
What was done
The authors modeled daily creatine requirements and calculated proposed adequate intake (AI) values for adults aged 19 to 65 years by integrating physiological estimates of creatine turnover, endogenous synthesis rates, and population dietary exposure data.
What was found
Daily creatine loss via creatinine conversion was estimated at 20 mg/kg/day in men and 15 mg/kg/day in women. Assuming endogenous synthesis covers 73% of daily losses and diet supplies the remaining 27%, the proposed AI was calculated to be 5.4 mg/kg/day for men (~400 mg/day for a 75-kg man) and 4.1 mg/kg/day for women (~240 mg/day for a 60-kg woman). The authors noted that typical omnivorous diets meet these requirements, whereas vegetarians, vegans, and older adults may be at risk for insufficient intake.
Why it matters
This technical framework provides the first proposed reference values defining dietary creatine requirements for maintenance in healthy adults and frames creatine as a conditionally essential nutrient for populations with low intake of animal products.
Limits
The recommendations are derived from theoretical modeling of turnover and synthesis rather than direct prospective feeding or depletion-repletion trials in humans. Individual biological variability, specific health conditions, and differences across age groups or physical activity levels were not directly tested in a clinical cohort.
Cited by
- supports Herring, salmon, and beef contain the highest natural concentrations of creatine, whereas milk and dairy contain only very small amounts.