Discussion Questions

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  What are the overall aims of the study?

  
  
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  How important is this question?

  
  
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  What is the NHANES dataset?

  
  
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  Can you describe this complicated analysis in simpler terms?

  
  
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  What information is in the tables?

  
  
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  What are the study’s strengths and weaknesses?

  
  
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  What do we learn about vitamin D supplementation?

This month, Journal Club members discussed a very interesting article by Ginde et al. The work focused on vitamin D levels in women of child-bearing age—pregnant and not—in the United States. Experts have been reassessing optimal vitamin D intake; specifically, whether more is better. Currently, the Food and Nutrition Board at the Institute of Medicine of the National Academies is examining dietary reference intakes for vitamin D and calcium and is due to release a report by the end of summer 2010.

One vital research area centers on how maternal levels of vitamin D relate to fetal development. Its influence on fetal bone formation is accepted, but maternal vitamin D levels may play a role in other aspects of fetal and child health. For example, some observational data suggest that inadequate maternal vitamin D status might predispose a child to asthma. In fact, in our department at Washington University in St. Louis, we are now recruiting participants for a randomized controlled trial that will test whether vitamin D supplementation in pregnancy might reduce the occurrence of childhood asthma. For all of the above reasons, Journal Club participants felt that this was an important study.