Doctoral Candidate Says Calcium and Magnesium Work Better Together

Public Health doctoral candidate Liam Fouhy sits behind a machine that measures bone density, in the Health Assessment Lab Image by K. Webster
Public Health doctoral student Liam Fouhy '19 sits behind a machine that measures bone density in the Health Assessment Lab.

By Katharine Webster

Getting the right balance of calcium and magnesium in your diet may help to prevent bone loss as you age, says Liam Fouhy ’19, a researcher and doctoral student in public health who specializes in nutritional epidemiology.

“Our research found that the balance is more important in preventing osteoporosis than meeting the recommended daily minimum of each mineral,” says Fouhy, whose analysis is based on the long-running Boston Puerto Rican Health Study of 1,500 older adults. His research was published in the Journal of Nutrition.

A ratio between 2:1 and 3:1 of calcium to magnesium in the diet appears to be most beneficial for strong bones, Fouhy says: “Anything above or below that appears to harm bone health.”

Calcium and magnesium “compete” to be absorbed by the same mechanism in the small intestine, Fouhy explains. If you consume too much of one mineral, it will crowd out the other, leading to an imbalance that can weaken bones over time.

But not to worry, he says – most people can get plenty of calcium and magnesium through a healthy and varied diet. In fact, his research looked only at people who didn’t use supplements.

Prime sources of both minerals include dairy products, seafood, meat, poultry, and fruits and vegetables grown in healthy soil, he says.

Vegans who want to make sure they’re getting enough of both minerals, as well as vegetarians who don’t tolerate dairy products or eggs well, might want to use a supplement that combines calcium, magnesium and Vitamin D and is certified by the NSF, the National Supplement Foundation, he says.

“We often research individual nutrients, but they really need to be looked at in context with one another because that’s how they’re consumed in food, and they interact with each other,” he says.

Fouhy’s research advisor is Nutritional Science Assoc. Prof. Sabrina Noel, director of community engagement for the UML Center for Population Health. The Boston Puerto Rican Health Study is led by Nutritional Science Prof. Katherine Tucker and Luis Falcón, dean of the College of Fine Arts, Humanities and Social Sciences.