Establishing creatine reference intakes for infants

The paper’s author, creatine expert Sergej Ostojic, MD, PhD, said that despite being extensively studied, creatine still falls outside the established frameworks for reference intakes and noted recent studies suggesting that creatine malnutrition is common across a range of age groups and populations. 

He explained that because human milk is recommended as the exclusive source of nutrition for healthy infants during the initial six months of life, determining the average intake of creatine for this population to promote optimal growth is straightforward.

“Establishing adequate intake levels for creatine (and providing enough creatine by food sources) could help recognize it as a conditionally essential nutrient in this population, as endogenous production may not meet the needs of a growing infant,” he told NutraIngredients-USA, adding that this is “merely the first phase of a broader project aimed at determining creatine requirements across various populations and conditions.” 

Professor Ostojic is affiliated with the Department of Nutrition and Public Health at the University of Agder in Norway, the Applied Bioenergetics Lab at the University of Novi Sad in Serbia and the Faculty of Health Sciences at University of Pecs in Hungary. He was also recently named among the world’s top 2% of scientists on this year’s Stanford University list.

Starting with creatine requirements in infancy​

In children, creatine is used for muscle and brain development, and while some creatine is made naturally in the body from amino acids like arginine, glycine and methionine, the rest must come from the diet or supplementation. 

Deficiency in this population may be linked to impaired intrauterine and postnatal growth and development, with the brain being the most affected organ. In some rare cases, the inability to synthesize and/or transport creatine can lead to severe neurodevelopmental challenges.

“Infancy (ages 0–1 year) marks a pivotal stage in human development, characterized by rapid growth and maturation of all organs,” Professor Ostojic wrote. “Creatine emerges as a crucial component in meeting the heightened requirements of skeletal muscles and brain during infancy.”

Acknowledging that the amount of creatine used by these two organs remains elusive, he revisited what is known about muscle creatine concentration, brain creatine accrual, creatine loss to creatinine and endogenous creatine synthesis in this population to determine a total requirement for creatine of approximately 73 mg/day.

The comprehensive LactMed human milk composition database was then used to evaluate the creatine content in breast milk, which Professor Ostojic reported varied across stages, maternal factors and geographies.

Recommendations for creatine intake in infants​

Due to a lack of evidence needed to calculate estimated average requirements for creatine in infants during their first year of life, Professor Ostojic suggested that the adequate intake could be used instead of recommended dietary allowance. To establish the adequate intakes for this population, the potential of creatine to mitigate the risk of small head circumference and support brain growth was used as surrogate marker. 

“The adequate intake for creatine can be established using the creatine concentration found in mature human milk between 15 days to 6 months and the average daily volume of breast milk consumed by infants,” Dr. Ostojik explained. The reference body weight ratio method was used to then extrapolate the adequate intakes for older infants.

The paper suggested that the adequate intake for creatine across Europe and North America is 7 mg/day for exclusively breastfed infants aged 0 to 6 months and 8.4 mg day for infants aged 7 to 12 months.  This would cover approximately 10% of the 73 mg/day requirements in young infants who are exclusively breastfed, suggesting a 1:10 ratio between exogenous provision and endogenous synthesis. 

“The recommendations are temporary and may change based on the amount of milk produced, nutrient levels during breastfeeding and the specific needs of each infant,” Professor Ostojic noted. “More research is needed to confirm if these amounts are suitable for different groups of infants and to create guidelines for creatine intake across other ethnicities.”

Source: Nutrition Reviews​
“Establishing Reference Intakes for Creatine in Infants Aged 0 to 12 Months”
doi: doi.org/10.1093/nutrit/nuae124​
Author: Sergej Ostojic