If you are healthy, living at home, and take calcium and vitamin D supplements to prevent broken bones or cancer, you may want to reconsider, according to the U.S. Preventive Services Task Force (USPSTF). The group's new draft recommendations, published online on June 12, add more fervor to the ongoing debate about the benefits and risks associated with these popular supplements.

The USPSTF based its recommendations on a meta-analysis of 136 clinical trials, observational studies and a systematic review evaluating the effects of supplementation on fracture and cancer risk. It concluded that postmenopausal women should not take supplements containing less than 400 international units (IU) of vitamin D and 1,000 milligrams of calcium, noting that there is not enough evidence to evaluate the effects of taking more than those amounts. There was also insufficient data for the task force to determine whether or not healthy younger women and men of any age should take the supplements.

There's no question that "vitamin D and calcium are essential nutrients for a healthy diet," says task force member Kirsten Bibbins-Domingo, an epidemiologist and biostatistician at the University of California, San Francisco. The heart, muscles and nerves cannot work properly without the minerals, and deficiency can also cause bone loss, osteoporosis and tooth damage. Vitamin D is crucial in part because it helps the body to absorb calcium from food. In May the USPSTF recommended that people over 65 take vitamin D supplements if they have an increased risk of falls, for instance because of mobility problems or a history of falling.

But for healthy people the benefits are less clear-cut, Bibbins-Domingo says. Part of the problem is that trials involving vitamin D and calcium are inconsistent—they test different doses for varying lengths of time in diverse populations, which "makes it extra tricky when you try to put them all together and come up with a final analysis," says Erin LeBlanc, an endocrinologist at the Kaiser Permanente Center for Health Research in Portland, Ore. Earlier this week LeBlanc and her colleagues published a study online in the Journal of Women’s Health suggesting that women over 65 with higher blood vitamin D levels gain less weight over time than women with lower amounts.

Despite the difficulty of making firm conclusions about the data, some experts find the USPSTF recommendations, which are open for public comment until July 10, misleading and potentially dangerous. "I think they went too far," says Susan Ott, a bone specialist at the University of Washington School of Medicine. For one thing, "they ignored a lot of people who are getting really no calcium in their ordinary diet."

Indeed, the recommendations only apply to healthy people who are not deficient in either nutrient. (The task force did not evaluate the benefits of supplementation in people with osteoporosis, but the National Osteoporosis Foundation recommends that people with the bone disease consume at least 1,200 milligrams of calcium and 800 to 1,000 IUs of vitamin D daily through food or supplements.) Although the Institute of Medicine maintains that most Americans get enough vitamin D from food and sunlight, the organization notes that nearly 75 percent of American women between the ages of 31 and 50 do not get the recommended 1,000 milligrams of calcium from their food every day, and that a similar percentage of women older than 50 fail to consume their recommended 1,200 milligrams. (To eat 1,000 milligrams without supplementing, a person would have to eat 16 cups of cooked broccoli or drink three and a third glasses of skim milk daily.) "There are a lot of people out there who are only getting half of what we recommend," Ott says, and the USPSTF recommendations do not apply to them.

11 Comments

1. 1. Kloumann 08:43 AM 7/2/12

   
   I've been on the fence about vitamin D and calcium for a while, but this finding adds even more weight to the idea that we humans (and probably all living things for that matter), should be getting our nutrients almost entirely from natural sources. At least whenever humanly possible.
   
   It's amazing how many seemingly educated people have no concept of this. When an acquaintance of mine told me of the mystery surrounding his various health problems:
   
   High blood pressure, high-cholesterol, acid-reflux and maybe even diabetes, his doctor is now telling him.
   
   So I decided he needed the truth, as much as it may annoy him. I pointed out that he eats at McDonald's at least every other day, and that the rest of his diet comes mostly from processed stuff like chips, low-quality microwaveable meals, sugary cereals ... and a whole lot of other mass-produced junk.
   
   His response was, "It's cool, I take some vitamins and stuff, so I don't really need fruits and vegetable."
   
   This one of the dumbest things I had heard someone say in months, so at the risk of sounding like a pretentious jerk, I encouraged him to read "In Defense of Food," by Michael Pollan. If you thought his reasoning was sound, you should too, but if you really don't want to, ask a nutritionist his/her take on processed food.
   
   
   
   On another note:
   
   Pretty bad typo here:
   
   "It concluded that postmenopausal women should not take supplements containing less than 400 international units (IU) of vitamin D and 1,000 milligrams of calcium, noting that there is not enough evidence to evaluate the effects of taking more than those amounts."
   
   
   Should say:
   
   "...women should not take supplements containing MORE than 400 international units..."
   
   Hope that gets fixed soon.
   
   The article is good otherwise.

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2. 2. Kloumann 08:47 AM 7/2/12

   I guess I'm capable of typos too, and pretty picky about them. I wrote:
   
   "When an acquaintance of mine told me of the mystery surrounding his various health problems:"
   
   Should have been:
   
   "An acquaintance of mine..."
   

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3. 3. mwenner 08:57 AM 7/2/12

   Hi Klourmann: Thanks for your interest in the piece. What you highlighted as a mistake is actually correct as written: the task force recommended that postmenopausal women should not take less than 400 International Units of Vitamin D, or less than 1000 milligrams of calcium, daily. It also concluded that there is insufficient evidence to determine whether postmenopausal women should take more than this amount.

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4. 4. Kloumann in reply to mwenner 10:11 AM 7/2/12

   I must be missing something crucial, because that wording still doesn't make sense to me.
   
   If the USPSTF say that people should reconsider taking these supplements, why would they advise postmenopausal women not to take LESS than a certain amount? Aren't they saying don't take too much?
   
   If they advise that these women "should not take supplements containing LESS than 400 international units (IU) of vitamin D and 1,000 milligrams of calcium" as written in the article, that would imply that it's okay to take 10,000 IU of vitamin D, or a million for that matter. But not 300, or even 1! I would also think it more dangerous to take 1,000,000 milligrams of calcium than 5 milligrams. But the above wording implies otherwise.
   
   It makes more sense to me that they would have advised postmenopausal women not to take "supplements containing MORE than 400 international units (IU) of vitamin D and 1,000 milligrams of calcium."

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5. 5. mwenner 11:14 AM 7/2/12

   Kloumann: it's confusing, but the recommendations are shaped around how the science was evaluated. The task force looked at two different sets of data: 1) data on the effects of taking <400IU of Vitamin D and <1000mg calcium, and 2) data on the effects of taking more than that amount. The panel found that 1) there was sufficient evidence to conclude that taking <400IU Vitamin D and <1000mg calcium is NOT beneficial. (There was lots of data, and the data were conclusive.) But as for 2), the effects of taking >400IU of Vitamin D and >1000mg calcium, there wasn't enough data for the panel to reach any conclusions. So it's possible that in the future, the panel might actually find that it IS beneficial to take more than 400IU Vitamin D and 1000mg calcium. But at this point, the panel doesn't know. It might help to take a look at the recommendations: http://www.uspreventiveservicestaskforce.org/draftrec3.htm
   

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6. 6. MadScientist72 11:51 AM 7/2/12

   Here's an idea - instead of the USPSTF (whoever they are - I thought the USDA was in charge of dietary guidelines) wasting our time & money releasing a report about "insuffucient data", why don't they go out an collect MORE DATA?

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7. 7. hlahore 09:13 PM 7/2/12

   Yes, need more than 400 IU of vitamin D to strengthen bones.
   That should have been the title.
   Need at least 800 IU of vitamin D
   Details at http://www.vitamindwiki.com/tiki-index.php?page_id=2921

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8. 8. george19 06:34 AM 7/3/12

   Why are we spending so much money on so many badly done studies. Anyone wanting info on Vitamin D should check out the website grassrootshealth.net. The problem with a lot of these studies is they don't use levels adequate to make a difference in the first place, and then they find that it's not effective.

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9. 9. jeanne8617 04:46 PM 7/6/12

   My doctor recommended 1000mg calcium w NO LESS than 400 mg vitamin D twice daily when I was diagnosed w osteopenia b. Made sense to me. No less than doesn't necessarily mean more than. Don't see where your confusion is Kloumann. I'd rather use the vitamin, on top of a healthy diet, than ignore my dr.s advice.

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10. 10. gonzo3363 12:30 PM 8/31/12

    This is probably the worst case of irresponsible reporting I can think of in a while. (not this article but all the others with the sensationalized headlines) All the headlines are reading "Post-menopausal women: Don't bother taking Vitamin D or Calcium"
    
    People reading this don't realize that this wasn't a study it was a study of studies which is the worst study there is.
    
    There is hard, very reliable evidence from multiple studies all across the globe that women with a low serum 25-hydroxy D have an increased risk of breast cancer. I am angered by these headlines that will make women "not bother" to take their doctor's advice of getting enough Vitamin D.
    
    Being a researcher and medical blogger, I have done MY research. It's too bad POOR research gets the headlines. Shame!

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11. 11. RubyWalters123 11:06 AM 11/6/12

    I agree with some of the other comments: I think humans were made to get their vitamins from natural sources when possible. That being said, sometimes its really just not practical for people's diets to include the amount of a specific vitamin or mineral (like calcium). For these people supplements are the best option. I have been buying <a href="http://www.truvite.com">online vitamins and supplements</a> for years and I only take a low dose and try to get as much from natural sources as possible. I am glad that I supplement my diet though because otherwise I am sure I wouldn't get enough.

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