Systematic review finds great regional differences, with lowest average calcium intake found among the world’s most populous countries—China, India, and Indonesia.

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 in the USA.

Calcium is a major building block of bone, accounting for about 30-35% 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% per year, resulting in calcium loss of approximately 15 g 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.

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 1233 mg/day;
• Southern and Eastern Asia had world’s lowest average calcium intakes—often less than 400 mg 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 1,000 mg a day.
• Significant variation was seen within regions as well: for e.g., in Latin America, Colombia showed one of the world’s lowest intakes with 297 mg/day while in Mexico the daily average was found to be 805 mg/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.

The study’s lead author Ethan Balk, associate professor at the Center for Evidence Synthesis in Health, Brown University School of Public Health, stated: "In many parts of the world there is lower intake than there should be for good bone 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."

The article titled, "Global dietary calcium intake among adults: A systematic review," was published in the journal Osteoporosis International.