If you live in the United States, chances are that you’re familiar with media ads with models and superstars sporting a frothy white milk mustache asking the question “Got milk?”
High in calcium, milk consumption is often encouraged in children to help promote the formation of healthy bones and teeth. The majority of all calcium -- 99 percent -- is stored in the bones and teeth.
The amount of calcium that you need varies depending on your age and sex. For example, the RDI for infants is only 200 mg daily, while the RDI for a 51-year-old woman is 1,000 mg daily and 1,200 daily for a woman over the age of 71 years.
Most of us lose calcium as we age but postmenopausal women, along with the elderly, are at particular risk for bone loss and osteoporosis due to depleted calcium levels.
As a result, it’s not uncommon for physicians to recommend calcium supplements to ensure that those at risk for osteoporosis and bone loss maintain adequate daily calcium supplies.
On the surface, taking a daily calcium supplement appears to be a quick and easy way to maintain calcium mineral levels.
It’s generally accepted that increasing calcium intake helps to prevent bone loss and osteoporosis. In addition, past research links high levels of calcium intake to lowering known risk factors for heart disease and stroke such as high blood pressure, type 2 diabetes, and obesity.
However, not everyone agrees that calcium supplements are as beneficial as previously thought. With findings counter to popular belief, according to one German study, taking calcium supplements may actually increase the risk of heart attack and caution is advised for those considering adding calcium supplements to their daily vitamin regime.
Study authors based their conclusions on records of participants in the EPIC,or European Prospective Investigation into Cancer and Nutrition study. In all, 24,000 EPIC participants were followed for a period of 11 years beginning in 1994.
All participants were between the ages of 35 and 64 years at the time they joined the study. Participants' diet was tracked, along with the type and frequency of supplements used.
Over the course of the study, 354 participants suffered a heart attack, 260 had a stroke, and an additional 267 participants suffered a heart-stroke related death.
After taking all factors into consideration, researchers found that participants who consumed at least 820 mg daily of calcium from all sources had a 31 percent lower risk of a heart attack than those consuming less calcium on a daily basis.
However, researchers found no protective benefits against heart attack and stroke when higher doses of calcium -- 1100 mg or more daily -- were consumed.
The real surprise came when researchers examined calcium supplement consumption separately from dietary calcium consumption.
Participants who consumed calcium supplements on a regular basis were found to have a significantly higher risk of heart attack -- 86 percent -- compared to participants who took no calcium supplements.
In addition, participants consuming only calcium supplements were also found to be two times more likely to have a heart attack than those participants who took no supplements at all.
Researchers concluded that taking calcium supplements may actually be harmful since supplements raise the calcium levels in the blood well above normal range. Findings indicate that consuming calcium via supplements doesn’t have the same metabolic benefits as when calcium is consumed naturally in the diet.
Study authors believe that consumption of calcium supplements should be discouraged and instead calcium should be consumed from natural, dietary sources.
Foods high in calcium include dairy products such as milk, yogurt, and cheese, and other foods such as spinach, broccoli and cabbage.
Sources:
Dietary Supplement Fact Sheet: Calcium. Office of Dietary Supplements, National Institutes of Health. 31 Aug 2011.
http://ods.od.nih.gov/factsheets/Calcium-QuickFacts/
http://ods.od.nih.gov/factsheets/Calcium-HealthProfessional
BMJ-British Medical Journal (2012, May 23). Calcium supplements linked to significantly increased heart attack risk, study suggests. ScienceDaily. Retrieved May 27, 2012, from
http://www.sciencedaily.com/releases/2012/05/120523200752.htm
Reviewed May 29, 2012
by Michele Blacksberg RN
Edited by Jody Smith