Vitamin D levels and Kawasaki Disease Original paper

In this meta-analysis in children, participants with Kawasaki disease had lower vitamin D levels.

The association between serum vitamin D levels and the risk of developing Kawasaki Disease (KD), a condition with increased inflammation of the arteries and an increased heart attack risk.

A total of 2,951 children (ages 0–5; 58% boys, 42% girls), of whom 1,394 had KD.

The participants were from China (73%), Italy (15%) and Japan (12%).

A meta-analysis of 17 observational studies was conducted.

The researchers conducted subgroup analyses to see if the nationality (from China or other countries) or condition status of the participants affected the results. In regards to condition status, the studies were divided into 3 groups: if the participants had coronary artery lesions (CAL; indicating a higher heart attack risk), no CAL, or mixed (i.e., the researchers did not assess for CAL).

Compared to participants without KD, participants with KD had lower vitamin D levels, with a large effect size, but the heterogeneity between studies was also large.

In subgroup analyses, each group had similar associations between vitamin D and KD risk (with large effect sizes), except for the CAL group which had no association.

Because 73% of the participants were from China, the generalizability of these results to residents of other countries is reduced.