Americans may not be getting enough calcium, suggests study
The study published the Journal of the American Dietetic Association, analyzed data from over 9000 people in the US population, finding that although calcium intake increases as we age many people still do not manage to maintain their recommended intakes.
The researchers found that 51 percent of all individuals over 19 years of age were taking a calcium supplement, with the percentage of individuals taking calcium supplements increasing in men from 34 percent in the 19-30 age group to 54 percent in the 81 plus group. In women, the percentages rose from 42 percent to 64 percent across the range of age groups.
“Calcium plays a fundamental role in promoting bone health and forestalling osteoporosis. In light of evidence that energy intake declines with aging, calcium dense foods and calcium supplements become vital factors in maintaining adequate calcium intake across the lifespan,” said Jane Kerstetter, a professor in the department of allied health sciences at the University of Connecticut.
The authors explained that the study is unique among those focusing on calcium intake in the US population because both dietary and supplemental sources were evaluated across adult age groups and compared to accompanying patterns in energy intake.
Calcium controversy
In contrast with the new study reporting that Americans do not get enough calcium, recent research published in the British Medical Journal has linked calcium supplementation to an increased risk of cardiovascular disorders, including heart attacks and stroke.
The BMJ study – a meta-analysis of 29,000 people (reported on here) – said that that whilst calcium has been shown to have modest benefits in reducing the incidence of fractures and improving bone health, the increased risk of heart problems outweighs the potential benefits.
Professor Ian Reid, senior author of the BMJ study told NutraIngredients: “When we do the calculations from these 29,000 people, we find that for every thousand people we give calcium to for five years, we cause six heart attacks and we prevent three fractures.”
Bone health
Research has, however, shown that multiple nutritional factors including vitamin D and calcium status play an important role in maintaining bone health. As such, calcium supplements have become increasingly popular in recent years.
The Institute of Medicine defines the Adequate Intake (AI) of calcium as 1,000 mg/day for individuals aged 19 to 50 years and 1,200 mg/day for persons older than age 51 years. However a recent study evaluating dietary calcium and vitamin D intake using data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) found that only 15 percent of men and 8 percent of women older than age 71 years had dietary calcium intakes meeting AI levels.
Using data collected from 9,475 adults during the NHANES study, Kerstetter and her colleagues investigated the decrease in energy intake reported by various age groups. They said that this is important because as people age, they consume less food, and therefore less calcium.
Study details
The research found that on average men's energy intake declined by 35 percent from the 19-30 age group to the 8 and over age group; from 2,668 kcal per day to 1,733 kcal per day. For women, energy intake showed a 28 percent reduction from the youngest to oldest age group; from 1,844 to 1,325 kcal per day.
The researchers concluded that although supplemental calcium use and calcium density were highest in older age groups, they were not sufficient in meeting recommended levels.
“New approaches to increasing the frequency and level of calcium supplement use to enhance calcium density in diets may be necessary to reduce osteoporosis risk among older Americans,” said Prof. Kerstetter and her team.
Source: Journal of the American Dietetic Association
Volume 111, Issue 5, Pages 687-695, doi: 10.1016/j.jada.2011.02.014
“Calcium Intake in the United States from Dietary and Supplemental Sources across Adult Age Groups: New Estimates from the National Health and Nutrition Examination Survey 2003-2006”
Authors: K.M. Mangano, S.J. Walsh, K.L. Insogna, A.M. Kenny, J.E. Kerstetter
