URBANA – A new gene-mapping study has identified nine previously unidentified genetic loci that may control calcium absorption, said James Fleet, a Distinguished Professor at Purdue University and the keynote speaker of the University of Illinois’s Division of Nutritional Sciences recent Nutrition Symposium.
“This finding points to significant gene-diet interaction and provides ‘proof of principle’ for the concept of personalized nutrient requirements for calcium,” Fleet said.
Although dietary calcium is essential for the proper strengthening of the skeleton in growing children as well as for the maintenance of bone mass in adults, many people consume low levels of calcium in their diet, he noted.
According to Fleet, previous research shows that the body recognizes this inadequacy by stimulating a physiologic adaptation that includes improved ability to absorb calcium from the diet. This process is dependent upon the nutrient vitamin D.
“If the diet is only moderately low in calcium, and if the adaptation is strong, the body can protect bone during these periods,” he said.
Fleet provided an overview of his published work on the mechanism by which vitamin D metabolites regulate intestinal calcium absorption.
He then presented new research on the role that genetics plays in controlling calcium absorption and the physiologic adaption to low dietary calcium intake.
This new work is aimed at identifying the genetic variation controlling why individuals or population subgroups—for example, racial groups—respond differently to low dietary calcium intake, he said.
This work may eventually allow scientists to recommend varying calcium intake for individuals, ethnicities, and races, he added.
“For example, we can see that Asian people are high-efficiency calcium absorbers, and we may be able to recommend less calcium for this group,” he said.