There are some facts that are incontrovertible: Our body tends to lose bone as we age, and weaker bones can lead to osteoporosis and an increased risk of life-threatening fracture. Other health information that’s still not as clear is the exact role of calcium and vitamin D supplements in promoting bone health.
There’s no shortage of studies on the topic of vitamin D and calcium to support bone health, and each one seems to come to a different conclusion. Part of the problem is that the individual studies aren’t always evaluating the same dosage and form of the nutrients—did researchers use D2 or D3, calcium carbonate or calcium citrate?—and that’s just one of the facts lost somewhere below the hyped headline, if it’s mentioned at all.
Last week’s report from the United States Preventive Services Task Force (the same group that recently recommended against routine prostate cancer screenings and proposed raising the baseline age for and frequency of mammograms) incited another round of groans. In essence, the group is suggesting that healthy postmenopausal women should not take low doses of calcium or vitamin D supplements to prevent fractures, and that there’s no evidence that taking vitamin D with or without calcium does any good in preventing fractures in healthy premenopausal women and men. These supplements do, rather, pose a small risk for developing kidney stones (other studies have implicated the duo in stroke and heart disease). Very important to note, the findings do not apply to women over 50 who already have and are battling osteoporosis or broken bones or have significant risk factors for fracture.
People posting on various blogs, including those for medical professionals, were quick to point out that it’s well acknowledged that the doses examined¬— about 400 IU or less of vitamin D and 1,000 milligrams or less of calcium a day—are too low to be effective and took exception to the guideline that Americans without osteoporosis can get all the calcium and D they need through diet, with some questioning the nutrient levels in our food on grocery shelves. (It should be noted that the body makes vitamin D naturally through sunlight, but skin cancer experts warn against any unprotected sun exposure, though 20 minutes is often all it would take. Also people in northern locations with less sun may not be able to see the sun enough to meet their needs). In fairness, there have been studies showing that the way to get the greatest benefits from calcium and vitamin D is to get from food sources, not in pill form. Foods often have additional micronutrients that can’t be perfectly replicated in the lab.
So how then do we interpret these statements? We went to the organization at the forefront of osteoporosis research and awareness, the National Osteoporosis Foundation. Here’s their position as posted on their website:
While calcium and vitamin D alone may not prevent fractures, the National Osteoporosis Foundation (NOF) believes that these nutrients are an important part of bone health management.
NOF recommends that all women age 50 and older, including healthy women and those with low bone density or osteoporosis, get 1,200 milligrams (mg) of calcium and 800-1,000 international units (IU) of vitamin D daily. This position is widely accepted within the medical community. “Everyone needs enough calcium and vitamin D for good health, especially for bone health. Media coverage of the recommendations that does not highlight the important benefits of these nutrients to bone health could lead individuals to stop taking the needed amounts without consulting with their healthcare provider,” said Robert Recker, MD, NOF President. “Osteoporosis medications don't work without calcium and vitamin D. We are concerned that insufficient intake of these nutrients could contribute to a greater number of broken bones.”
NOF encourages all individuals to choose calcium-rich food sources first. Supplements should be used to make up for a shortfall of calcium in the diet. Because there are few dietary sources of vitamin D, and the use of sunscreen is widespread, most people will need to take a vitamin D supplement to achieve and maintain healthy vitamin D levels.
“The USPSTF’s conclusions that 1,000 mg a day of calcium and 400 IUs of vitamin D do not prevent fractures in healthy women are not surprising. We have known for a long time that calcium and vitamin D are critical but are not enough alone to prevent fractures, and in high risk women, medication to lower fracture risk is also needed. Sufficient amounts of calcium and vitamin D are essential to the overall treatment plan for women at increased risk of breaking a bone. This includes women with low bone density, osteoporosis and those with previous fractures,” said Dr. Ethel Siris, Immediate Past President of NOF. “Many women need to add a supplement to their diet to ensure they are getting enough calcium and vitamin D; however, the media reports are confusing and will likely lead women in these higher risk groups to stop taking the appropriate supplements altogether. This would be harmful to their bone health.”
NOF strongly urges all individuals to get the recommended amounts of calcium and vitamin D to protect bone health. Patients should talk to their healthcare providers about their individual needs for calcium and vitamin D and never discontinue supplements without checking first with their doctor.
What else you need to know: