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Lay off the mega-doses of Vitamin D

Rating

4 Star

Tags

Lay off the mega-doses of Vitamin D

Our Review Summary

The story urges readers to be cautious about consuming vitamin D supplements — particularly in high doses, which can increase a variety of health risks. The story stems from a recent commentary in the Journal of the American Medical Association, which expressed skepticism about the wisdom of prescribing high doses of vitamin D and pointed to the lack of evidence that high doses of vitamin D were associated with health benefits.

We’re admittedly fans of any story that casts a skeptical eye on interventions that aren’t supported by solid evidence, and our (mainly positive) review reflects that slant. But we do offer some suggestions for how this story could have upped its game. A second expert perspective, or some cost information, would have added a fifth star to this story’s score.

 

Why This Matters

Vitamin D use has increased significantly over the past 15 years; Consumer Reports reported that sales of vitamin D supplements rose from $40 million in 2001 to $425 million in 2009. While some articles, including the recent one in JAMA, have tied this increase to guidance from doctors, news outlets may also have a role. A 2014 study published in BMJ Open examined 294 newspaper articles and found that the articles not only “generally supported” the use of vitamin D supplements, but also “linked vitamin D to a wide range of health conditions for which there is no conclusive scientific evidence….and overlooked any potential risks.” Given that vitamin D is a big (and growing) business, with a range of possible health effects for those who take excessive amounts, it’s a subject worth tracking for doctors, consumers, and any reporters who write about the subject.

Criteria

Does the story adequately discuss the costs of the intervention?

Not Satisfactory

The story does not discuss the price of vitamin D supplements (a quick online search indicates that supplements can range in price from less than $4 to more than $80 for 180 capsules). The story also says that the recommended dietary allowance of vitamin D can be met by eating “three or four servings each day of ‘fortified’ foods such as milk, yogurt, soy beverages, orange juice or cereal, plus fatty fish twice a week.” Probably not an issue for most readers, but those aren’t necessarily low-cost foods for people on a budget — and some of those foods may be unavailable to people who live in “food deserts.”

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Satisfactory

The story talks about vitamin D-rich foods and supplements (including high-dose supplements). Are there benefits? Yes, and the story addresses (some of) them. The story makes clear that vitamin D is an essential nutrient for bone health, and that if you cannot get enough vitamin D from your diet (or from exposure to sunlight), then supplements can help you reach your target vitamin D consumption goal — which is 600 international units (IUs) per day for men and women between the ages of 1 and 70. The story could also have mentioned that vitamin D is involved in a variety of other health functions, including “modulation of cell growth, neuromuscular and immune function, and reduction of inflammation,” according to the CDC.

Another strong point of the story is explaining that many of the purported health benefits of high-dose vitamin D supplementation — for example, prevention of cardiovascular disease, diabetes, and cancer — have not been based on strong scientific evidence.

Does the story adequately explain/quantify the harms of the intervention?

Satisfactory

The story tells readers that taking large doses of supplements (above 4,000 IUs) can increase your risk of kidney stones, calcification of blood vessels and cardiovascular disease. Vitamin D toxicity is rare, but given the current enthusiasm for supplementation, it’s good for stories to voice some caution.

Does the story seem to grasp the quality of the evidence?

Satisfactory

The story was prompted by a perspective piece by Dr. Manson, a leading expert in vitamin D and health outcomes. The main topic of the commentary is the lack of evidence supporting high-dose vitamin D supplementation. The story conveys that message first by stating that “physicians are prescribing large doses of Vitamin D…in the hope of preventing cancer…and other maladies, despite a lack of evidence that this works.” To back this up, the story relies on a quote that “there’s been a disconnect between the observational studies and the randomized clinical trials to date.” This is all correct, but admittedly a bit vague and potentially confusing for readers. How is an observational study different from a randomized trial, and which one provides stronger evidence?  Which studies have fallen short of showing positive health effects? Which health effects were those studies evaluating? Is this an area that may be affected by the bias against publishing negative results?

A bit more detail and explanation would have been welcome here. But since the overall message of the story is consistent with the evidence on this topic — i.e. the story clearly “grasps the quality of the evidence” — we’re inclined to rule this satisfactory.

Does the story commit disease-mongering?

Satisfactory

No disease mongering here. The story clearly says that vitamin D supplements make sense if you’re not getting enough vitamin D in your diet, and also notes that taking high doses of vitamin D increases the risk of adverse health outcomes.

Does the story use independent sources and identify conflicts of interest?

Not Satisfactory

The story cites only two sources: Dr. Manson and the JAMA commentary co-authored by Manson. While Dr. Manson would normally qualify as an independent expert source in any story on vitamin D, here she’s basically being asked to comment on an article that she wrote which is the basis for the story. The story would have been much stronger if it had also included input from someone who didn’t author the JAMA commentary.

Does the story compare the new approach with existing alternatives?

Satisfactory

The story lays out what constitutes a healthy amount of vitamin D, how people can get that amount of vitamin D through their diet (or sunlight), and that some supplements may be needed.

Does the story establish the availability of the treatment/test/product/procedure?

Not Applicable

The story doesn’t go into this, but it doesn’t really need to. Vitamin D supplements are available online and have long been available in many grocery, drug, and health stores. We’ll rate it not applicable.

Does the story establish the true novelty of the approach?

Satisfactory

The story provides the background on why this issue is worth writing about now. It notes that over the past 15 years, observational studies “have been reported by the media as suggesting that vitamin D has these benefits” (i.e. cancer and cardiovascular disease prevention). It explains that these studies have promoted a “more is better” approach that isn’t supported by the evidence. It notes that there’s a large clinical study of vitamin D underway that should help answer many of the questions surrounding vitamin D.

Does the story appear to rely solely or largely on a news release?

Satisfactory

The story does not appear to draw from a news release.

Total Score: 7 of 9 Satisfactory

Comments (1)

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Judith Ronat M. D.

March 2, 2015 at 10:31 am

People expose themselves less to sunshine for fear of melanomas. And doctors measuring the blood level of Vitamin D has become common. So when the level is low, doctors prescribe Vitamin D to be taken by mouth. I have not found research reports, but it seems that Vitamin D is absorbed better if taken in oil based liquid rather than pills. If the doctor has prescribed pills, and the blood level doesn’t rise, he may prescribe more and more, until “mega doses” are reached.

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