Large study also found racial differences in anemia, vitamin levels
TUESDAY, Oct. 22, 2013 (HealthDay News) -- Children with low levels of vitamin D may be at increased risk for anemia, according to a large new study.
Researchers analyzed blood samples from more than 10,400 children and found that vitamin D levels were consistently lower in youngsters with anemia, a condition involving lower-than-normal levels of red blood cells.
Kids with vitamin D levels below 30 nanograms per milliliter (ng/ml) were nearly twice as likely to have anemia as those with normal vitamin D levels.
Children with vitamin D levels below 30 ng/ml have mild vitamin D deficiency while those with levels at or below 20 ng/ml have severe deficiency, according to the study. Both require treatment with vitamin D supplements.
The researchers also found that 14 percent of black children had anemia, much higher than the 2 percent rate among white children. Black children also had lower vitamin D levels overall, but their anemia risk did not rise until their vitamin D levels were far lower than those of white children.
These racial differences suggest that current targets for preventing or treating these conditions may require further research, according to the authors of the study, which was published online recently in the Journal of Pediatrics.
"The clear racial variance we saw in our study should serve as a reminder that what we may consider a pathologically low level in some may be perfectly adequate in others, which raises some interesting questions about our current one-size-fits-all approach to treatment and supplementation," study lead investigator Dr. Meredith Atkinson, a pediatric kidney specialist at the Johns Hopkins Children's Center, said in center news release.
The study does not, however, prove a direct cause-and-effect link between vitamin D levels and anemia risk, the researchers said.
Added senior study investigator Dr. Jeffrey Fadrowski, also a pediatric kidney specialist at Johns Hopkins: "If our findings are confirmed through further research, low vitamin D levels may turn out to be a readily modifiable risk factor for anemia that we can easily tackle with supplements."
The researchers explained that several mechanisms could account for this association, including vitamin D's effects on red blood cell production in the bone marrow or its ability to regulate immune inflammation, a known trigger of anemia.
The Nemours Foundation has more about anemia in children (http://kidshealth.org/parent/medical/heart/anemia.html ).
SOURCE: Johns Hopkins Medicine, news release, Oct. 21, 2013