This piece reports on an unpublished, observational study, which found that daughters of mothers who reported a high intake of vitamin D while pregnant have a lower risk of developing multiple sclerosis (MS). This story has numerous flaws, the biggest of which was relying exclusively on the press release. Two other major flaws were not including the caveat that this research has yet to undergo peer review and not explaining the limitations of such an observational study.
News stories should use caution when reporting on research presented at scientific meetings. The results are generally preliminary and can change. Furthermore, it has not undergone a rigorous review process to make sure the evidence is sound. In short, the research might not be ready for primetime.
A discussion of cost is not necessary on this topic in this context.
The story only presented the results in terms of relative risk, rather than absolute risk (56% lower than what?). Additionally, the story suggests that daughters of mothers who drank 4 glasses of milk per day had a lower risk of MS compared to those whose mothers who drank 3 glasses of milk per day. However, we’re not told whether this difference is statistically significant.
We don’t know if any of the mothers who reported a high intake of vitamin D experienced adverse effects; however, it’s worthwhile to mention that excessive intake of vitamin D supplements is associated with harms, including nausea, vomiting, constipation, and weakness. Additionally, information about how to safely get enough sun exposure to convert vitamin D to its active form would have been helpful.
This story failed to point out the limitations of having the mothers answer questions about their diets during pregnancy many, many years after the fact. The story also should have emphasized that only daughters were included the study, and it’s unclear whether this same protective effect would be seen in males.
Furthermore, the story mentions that the researchers will present these findings at the upcoming American Academy of Neurology’s meeting, but does not explicitly state that the research has yet to be published in a medical journal. Unlike published articles, this study has not gone through a rigorous review process.
This story did not exaggerate the prevalence or seriousness of MS.
No independent experts were interviewed for this story.
There was no mention of vitamin D supplements, but the story discussed main sources of the vitamin, including milk, fish, fortified foods, and sunlight.
The story lists common sources of vitamin D, all of which are widely available.
The story indicates that other studies have found a link between vitamin D and MS.
The information in this piece was taken directly from the American Academy of Neurology’s news release. There is no sign of any independent reporting.