Calcium Intake as You Age
Health and Wellness
June 26, 2011
The study looked at data from more than 9,000 adults from the National Health and Nutrition Examination Survey. Diet was assessed with 24-hour recall and supplement use via questionnaire. Researchers found that although supplemental calcium use and calcium density were highest in older age groups, they were not sufficient in meeting recommended levels.
Upon further examination, median dietary calcium intake in men decreased by 22.7% from the youngest to the oldest age group (from 942 mg/day to 728 mg/day); in women, it decreased by 14.1% (from 686 mg/day to 589 mg/day). The percentage of those taking supplements increased in men from 33.5% in the 19 to 30-year age group to 53.9% in the 81-year age group, and from 42.1% to 63.6% in women across the range of age groups.
It seems that while many individuals were turning to supplement use to replenish their calcium supplies, they were not in high enough amounts to reach Adequate Intake (AI) levels. Part of the problem here is that after age 30, energy intake for both men and women starts to decline – by 35% in men from the 19 to 30-year age group, and by 28% in women. Therefore, there are age-related reductions in energy intake on calcium nutrition. However, calcium requirements stay constant as we age and even increase in women after age 51 years. Therefore, for calcium, a 30% decline in intake is not desirable particularly since older adults are at the highest risk for an osteoporotic related bone fracture.
“Essentially, as caloric intake decreases, the possibility of increasing calcium density solely through changes in dietary composition becomes more difficult. Thus, the study findings highlight the need for most older individuals to utilize some form of calcium supplementation in order to reduce the risk of osteoporosis as they age,” says Dr. Jane Kerstetter, study co-author.
Interestingly, individuals who take supplements are actually more likely to consume dietary calcium in higher amounts, suggesting that awareness of the issue may increase their overall calcium intake, both from food and supplements, even though their dietary calcium intake does decline over time. In contrast, among femalenonusers of supplements, dietary intake is lower, but remains relatively constant across age groups. Researchers believe that the decline of dietary calcium in supplement users could potentially result from a false sense of security created by taking a calcium supplement, and thus leading to less attention, over time, to dietary sources.
Preventing bone loss, especially in older adults, is extremely important, considering that fractures are the 12th leading cause of disability in the U.S. The Institute of Medicine has defined the AI of calcium as 1,000 mg/day for people aged 19 to 50; recommended intakes increase to 1,200 mg/day for women older than 51 and men over 70 y of age. But as we age and consume less energy, our calcium intake also declines.
Encouraging calcium supplementation is an established approach to addressing this issue in the clinical setting, and one that needs additional emphasis. But there are variable definitions of “nutrient density”. Once a standard definition is set, says Kerstetter, retailers may then be able to market food products if their foods fit the standard criteria. In this way consumers will be able to make informed decisions on which foods are nutrient dense so that they will be more equipped in meeting recommended intakes. In the meantime, most milk based foods, particularly if they are from lower fat dairy, will naturally contain a high amount of calcium per energy content and should be advertised as calcium rich food sources.
There are many possibilities as to why many Americans are not consuming enough calcium rich foods to meet recommended intake levels. For example, some individuals are lactose intolerant, and therefore cannot tolerate calcium rich dairy products which supply a large amount of calcium to the diet. Or, perhaps we are consuming less dairy foods because of cultural differences, fear of additional calories, distaste, or inconvenience. Regardless of the cause, says Kerstetter, inadequate dietary calcium intake means that we will be utilizing the calcium stored in our skeleton for important metabolic functions. Consequences of chronic low calcium intake can be dangerous because when we use calcium from our bones at a rapid rate, we accelerate bone loss and significantly increase our risk for fractures.
“With the overall decrease in food intake that occurs over the lifespan, individuals must find ways to eat a more calcium rich diet while consuming less calories, possibly in combination with calcium supplements to reach recommended intake levels,” adds Kerstetter.