Published in The Journal of Nutrition, the study by researchers associated with the International Life Sciences Institute (ILSI) applied a calcium bioavailability algorithm to Food and Agriculture Organization (FAO) Food Balance Sheet data.
The model accounts for total calcium content alongside the effects of phytate and oxalate, compounds that can reduce mineral absorption.
The researchers found substantial geographical differences in estimated calcium bioavailability.
Bioavailable calcium represented approximately 19% of the food supply in Africa and 23% in Asia, compared with 49% across EU member states and 47% in the US, according to the analysis.
Lower levels were also identified across parts of Southeast Asia, South America and the Middle East.
The findings are particularly relevant to formulators, as they suggest that assessments based solely on total calcium content may overestimate the amount of the mineral available for absorption.
The researchers noted that some countries appearing to meet calcium reference values based on total calcium availability fell below those thresholds once bioavailability was taken into account.
Implications for mineral formulation
The study could support greater consideration of calcium bioavailability when developing food fortification strategies, dietary supplements and mineral ingredients, particularly for populations whose diets are relatively high in plant-based foods and lower in dairy.
Balchem partially funded the research and collaborated with ILSI to develop the calcium bioavailability algorithm.
“These findings underscore the need to raise awareness of the impact that these anti-nutrients can have on mineral nutrition,” said Dr Eric Ciappio, Senior Manager, Nutrition Science, Balchem HNH.
Ultimately, if calcium cannot be properly absorbed due to the presence of anti-nutrients, many people are missing out on crucial health benefits.
“Looking forward, Balchem is excited to continue supporting ILSI’s work as they adapt the model used in this study to investigate the impact of anti-nutrients on the bioavailability of other minerals such as iron.”
The researchers emphasised that the analysis measures food supply availability rather than actual dietary intake, and does not account for individual dietary requirements or life-stage differences.
