Bad for the bones: Average calcium intake varies widely around world, study notes

30 Oct 2017 --- A new study led by an International Osteoporosis Foundation (IOF) research committee has found that daily average calcium intake among adults varies widely around the world. Critically low intake was found in certain Asian, African and Latin American countries, while studies showed nearly double the intake in many European countries and the US.

Calcium is a major building block of bone, accounting for about 30 to 35 percent of its mass and much of its strength. The impact of calcium intake is most significant during adolescence, when the skeleton gains bone mass, and during later life when bone loss occurs at a rate of about 1 percent per year, resulting in calcium loss of approximately 15g per year. A major concern is that in countries with sub-optimal dietary calcium intake the population may be putting itself at increased risk of osteoporosis and related fractures.

Striking regional trends
The researchers looked at the scientific literature and other data sources for eligible studies that reported national averages of daily calcium intake among adults around the world. The studies varied widely, including by how nationally representative they were, and by their sample size. Nevertheless, there were enough eligible data for 74 countries, which revealed several notable regional trends:

• Across the 74 countries with data, average national dietary calcium intake ranges from 175 to 1,233mg per day.
• Southern and Eastern Asia had world's lowest average calcium intakes – often less than 400mg a day.
• Countries in South America and Africa mostly had average intakes in the mid-range, between about 400 and 700 mg a day.
• Only Northern European countries registered calcium intakes greater than 1,000mg a day.
• Significant variation was seen within regions as well: for example, in Latin America, Colombia showed one of the world's lowest intakes with 297mg per day while in Mexico the daily average was found to be 805mg per day.
• Average calcium intake is generally lower in women than in men, but there are no clear patterns across countries regarding relative calcium intake by age, sex, or socioeconomic status.

“In many parts of the world there is lower intake than there should be for good bone health,” states the study's lead author Ethan Balk, Associate Professor at the Center for Evidence Synthesis in Health, Brown University School of Public Health. “While consumption is highest among adults in North America and Europe, it is alarmingly low in Asia and in some of the world's most populous countries, including in China, India and Indonesia.”

IOF expects that the data will motivate action to promote increased calcium consumption, particularly in the Asia-Pacific region and in places where calcium consumption hasn't been documented. An interactive online global map representing the study findings will be launched by IOF on the occasion of the World Congress on Osteoporosis, Osteoarthritis and Musculoskeletal Diseases in April 2018.

“This study draws attention to regions where calcium intake needs to be assessed and where measures to increase calcium intake would likely provide skeletal benefits for the population,” states Bess Dawson-Hughes, M.D, Chair of the IOF Calcium Steering Committee and Director of the Bone Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. “This is a necessary first step in developing culturally appropriate strategies and policies to address the deficiency.”

The study “Global dietary calcium intake among adults: a systematic review” has been published in the journal Osteoporosis International.

The news of the study’s results comes soon after it was noted at the World Dairy Summit that around a fifth of teenage girls around the world are currently falling short of their recommended daily intake of calcium. It was pointed out by Dairy UK that the decision of teenagers who turn away from dairy could be having a deleterious effect on their long-term health.