As the world population ages, adult bone health is becoming even more of a concern. Scientists continue to tackle one of the most controversial relevant questions: Do calcium and vitamin D supplements actually help protect the bones?
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According to new research from scientists in China, the answer is no; vitamin D supplements and calcium do little to ward off brittle bones and protect against fractures.
The meta-analysis included data from 33 randomized clinical trials since 2006 comparing calcium, vitamin D, or combined calcium and vitamin D supplements for the incidents of fractures in 51,145 “community-dwelling older adults,” or adults over age 50 who lived on their own.
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Previous research has found that about 40 percent of women in that age group will have at least one "major osteoporotic fracture" at some point in their lives, and that among adults who break a hip, 20 percent died within a year of their injury, the Los Angeles Times reported.
The results:
According to the study, there was no significant association of calcium or vitamin D with a lower risk of fractures among the participants.
- No statistically significant relationship between calcium supplement pills and risk of suffering a hip fracture
- No statistically significant relationship between calcium supplements and spine or other bone fractures
- Amount of calcium consumed in diets and the dose of calcium pills didn’t help lower risk of fractures
- No statistically significant link between vitamin D supplements and hip fracture, spine and other bone fracture risk
- Among those who started out with at least 20 nanograms of vitamin D per milliliter of blood, adding more vitamin D via supplements was associated with a greater risk of hip fractures.
- There’s a link between those who took high doses of vitamin D supplements just once a year and higher hip fracture risk.
- Combined calcium-vitamin D supplements: No statistically significant link between use and risk for any kind of fracture
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But, according to the research, it’s still possible that calcium and vitamin D supplements are helpful for people who live in nursing homes or other residential facilities, a group more likely to have osteoporosis due to a variety of factors, including less sun exposure and poor diet.
Questions about the role of calcium and vitamin D supplements have been raised for decades. In 2013, the U.S. Preventative Services Task Force, a federal advisory board, said evidence that supports the benefit of supplements in older adults without osteoporosis or vitamin D deficiency was "insufficient," the Washington Post reported.
Both calcium and vitamin D have been recognized as important to bone maintenance, but the best way to get the daily recommended dose of calcium and vitamin D is by eating calcium- and vitamin-D-rich foods or getting some sun exposure.
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“As North Americans take more supplements and eat more of foods that have been fortified with vitamin D and calcium, it becomes more likely that people consume high amounts of these nutrients,” the Institute of Medicine wrote in 2010. The group warned of the possibility of kidney and tissue damage from overconsumption.
Recommended daily vitamin D and calcium intake for adults:
Vitamin D
“The recommended daily amount of vitamin D is 400 international units (IU) for children up to age 12 months, 600 IU for ages 1 to 70 years, and 800 IU for people over 70 years,” according to the Mayo Clinic.
Calcium
Study limitations:
Daniel Fabricant, president of the Natural Products Association, which represents manufacturers and retailers of dietary supplements, told the Washington Post the research makes its conclusions with "too broad a brush" and said the new study had limited information on the dosages involved.
“Maybe the average dose was on the lower end of dose response curve,” he said. “While it’s a nice exercise of mathematics, it doesn’t get at the actual issue which is what are optimal levels for people who need the supplements.”
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Some of the trials examined in the study also didn’t test baseline vitamin D blood concentration for all participants, the Washington Post noted.
Read the full study published Tuesday in the Journal of the American Medical Association.
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