"It would be good for them to turn off the TV and send their kids outside." That’s the advice one study author gave another news organization (www.livescience.com) about what to do about children who aren’t getting enough vitamin D. It’s tempting to recommend that same action to viewers who saw the CBS Evening News promote reliance on supplement pills.
The story combined information taken from studies on both vitamin D levels and fish oil recommendations in two different medical journals. The story did not include any independent experts, despite the fact that many experts and organizations are skeptical about the conclusions of the authors of these studies. The story also left out cautionary statements in the studies about the need to do randomized controlled experiments before recommending vitamin D supplements for children.
Perhaps the worst offense was the misuse of graphics. It is a tenet of television that when the pictures and the words send conflicting messages, the pictures always win. Yet as the CBS doctor talked about eating more fish, viewers saw pictures of fish oil supplement capsules. During the studio lead, as the anchor talked about 7 out of 10 children “not getting enough” vitamin D, the graphic behind her said “Vitamin D Deficiency,” even though the study reported that fewer than 1 in 10 children was actually deficient.
Costs were not mentioned. However, since we can assume that many people know these ballpark costs, we’ll rule this as not applicable.
The story says that taking more vitamin D and fish oil will reduce the risk of heart disease. But the recommendations cited are not universally accepted. Viewers are presented with stark black-and-white conclusions when reality is foggy gray.
Harms are not mentioned.
According to the National Library of Medicine’s MedlinePlus, the intake of vitamin D recommended in this story (400 units/day), taken along with calcium, has been associated with a 17% increase in kidney stones in older women. Mental confusion, heart rhythm abnormalities, nausea, vomiting, poor appetite, constipation, weakness, and weight loss are also potential side effects.
Besides causing gas for many people, fish oil supplements may also cause diarrhea, bloating and abdominal pain. It may also slightly increase the risk of bleeding, thus perhaps presenting some danger to people with bleeding disorder. Depending on the source, fish oil supplements may be contaminated with mercury, PCBs, and dioxin.
The story leaps far beyond the available evidence, even mis-reporting what the study authors wrote. It confuses association with causation and portrays the opinions of some doctors as being established consensus recommendations.
Although the story says vitamin D is “associated” with heart disease risk factors, the overall thrust of the piece is that “low” vitamin D levels cause heart disease… which is not what the studies say. As the authors of one of the vitamin D studies wrote, “causality cannot be established. Randomized, placebo-controlled clinical trials evaluating the beneficial effects of vitamin D supplementation on cardiovascular risk factors are needed to establish these as causal relations.” The other new vitamin D study concluded, “Evidence from randomized clinical trials is required before vitamin D supplementation can be recommended in the primary prevention of metabolic cardiovascular risk factors in youth.”
In other words, many children may have vitamin D levels lower than some doctors believe is healthy, but it is simply not known whether giving children supplements will make them healthier.
And while the authors of the fish oil study did indeed offer their recommendations for daily intake, other news reports included comments from skeptical experts. MedPageToday.com quoted one expert as saying, “I don’t find the evidence for widespread usage of omega-3 particularly compelling.” Another expert also said that while recommending that patients boost their consumption of fish oil maybe reasonable, people need to be cautioned about the strength of the evidence of fish oil benefits.
The story confuses lab test results with actual diseases.
The story highlighted a finding that 7 out of 10 children involved in a national survey had blood test levels of vitamin D that were lower than the authors of the study believe is healthy. However, the cutoff they used (30 ng/ml) was called controversial in a recent NIH fact sheet on Vitamin D. The NIH statement also noted that “a recent government-sponsored expert panel concluded that insufficient data are available to support these higher levels.” In other words, there is uncertainty and debate about whether the vitamin D levels considered “insufficient” are indeed linked to health risks.
[Dietary Supplement Fact Sheet: Vitamin D. Office of Dietary Supplements, National Institutes of Health, http://ods.od.nih.gov/factsheets/vitamind.asp]
What’s more, a graphic displayed during the anchor lead says “Vitamin D Deficiency” while the anchor talks about 7 out of 10 children not getting enough. However, the study said only 9% of children are deficient in vitamin D. The remaining 61% had lower, but not necessarily deficient, blood levels of the vitamin.
The story also leaps to the conclusion that people not loading up on fish oil are damaging their health. By not telling viewers that most of the evidence about fish oil effects has been gathered in people who are already sick, and that there is very little information about the effects in healthy people, the story raises a false alarm.
No independent sources were included in this story. Viewers were not told that the vitamin D recommendations from the American Academy of Pediatrics have not been adopted by other health agencies and organizations.
The vitamin D studies were funded by federal grants, but that information was not included in the story. No information about the authors of the fish oil story was included.
While the story does talk about getting vitamin D and fish oil in foods… and mentions sunlight as a source of vitamin D… the presentation is biased toward supplements, in part by emphasizing claims that people are not getting enough vitamin D or fish oil without discussing the diets of the participants in the studies. As dietary intake of fish oil is discussed, the on screen graphic shows fish oil pills, not fish.
Notably, the study reporting low levels of vitamin D in children said that the risk of low vitamin levels was highest in children who watch a lot of TV. This link was not reported in the story.
The segment didn’t address availability but we can assume that most people know that both vitamin D and fish oil are widely available, so this criterion is ruled not applicable in this case.
The lead of the story is “new recommendations.” However, neither the recommendations nor the data behind them are particularly new.
An NIH fact sheet posted online in April listed the same data on vitamin D levels in children that formed the basis of the studies quoted in this story. The fish oil recommendations are based on a review of earlier studies, not new information.
We can’t be sure if the story relied on a news release.