According to the organization, 89% of those who used its IOF Calcium Calculator, based on recommendations from the Institute of Medicine, were calcium deficient.
"These findings suggest that many people may not be aware of the importance of bone-healthy nutrition,” said Judy Stenmark, CEO, IOF.
“A healthy, balanced diet combined with regular exercise and smart lifestyle choices, such as not smoking and moderate alcohol intake, helps set the foundation for strong bones as you age. For those at high risk of fracture due to osteoporosis, a bone-healthy diet also supports falls prevention and enhances the benefits of therapy."
According to IOF, adults require around 1000mg of calcium per day. Meanwhile, children aged nine to 18 should ingest 1300mg and those over the age of 70 at least 1200mg.
On average, a glass of 2% milk contains 295mg of calcium.
The Calcium Calculator study, which involved 6,909 individuals from more than 80 countries, found that the average intake per day was 594mg.
Only 11% of people had the proper amount of calcium per day. Another 29% of respondents had been diagnosed with osteoporosis or osteopenia at some point.
"Recent controversial reports in the media in regard to calcium, vitamin D and the role of supplementation may be causing confusion,” Stenmark said, talking about recent studies that have questioned the importance of additional calcium for bone health.
“The important thing to remember is that achieving recommended dietary intakes of calcium and vitamin D, together with other important nutrients, is necessary for optimum bone health.”
Downsides of calcium deficiency
According to Healthline, symptoms of calcium deficiency can include memory loss, muscle spasms, depression, hallucinations and numbness and tingling in the hands, face and feet.
As people age, complications can become more dire and include an increased risk of osteoporosis, a disease where bone mass is lost and bones become more brittle.
This can lead to fractures of bones, an inability to walk and long-term disability.
Risks of hypoglycemia, also caused by calcium deficiency, can also include brittle bones, eye damage and abnormal heartbeat.
“Calcium needs should be met through food sources primarily,” Stenmark said. “Supplements may be beneficial if adequate calcium intake cannot be met through the diet, especially where certain medical conditions exist. Anyone with concerns should speak to their doctor who can advise appropriately."
The best dairy sources of calcium, according to IOF, include 335mg per 4oz of ricotta cheese, 310mg per 6oz of yogurt and 300mg per 8oz of milk.
Yogurt, mozzarella and cheddar are also high on the list.