Low Vitamin D Levels Raise Anaemia Risk in Children
22nd October 2013
Low levels of vitamin D appear to increase a child’s risk of anaemia, according to new research published in the Journal of Pediatrics, the first to extensively explore the link between the two conditions in children.
Anaemia, which occurs when the body doesn’t have enough oxygen-carrying red blood cells, is believed to affect one in five children at some point in their lives. Long known for its role in bone development, vitamin D has recently been implicated in a wide range of disorders. Emerging evidence suggests that low vitamin D levels may play a role in the development of certain cancers and heart disease and lead to suppressed immunity.
To capture the interaction between the two conditions, researchers studied blood samples from more than 10,400 children, tracking levels of vitamin D and hemoglobin, the oxygen-binding protein in red blood cells. Vitamin D levels were found to be consistently lower in children with low hemoglobin levels compared with their non-anemic counterparts. Interestingly the sharpest spike in anemia risk occurred with mild vitamin D deficiency, defined as vitamin D levels below 30 ng/ml (the equivalent of 75nmol/L in the UK) . Children with levels below 30 ng/ml had nearly twice the anaemia risk of those with normal vitamin D levels. Severe vitamin D deficiency is defined as vitamin D levels at or below 20 ng/ml (50nmol/L in the UK). Both mild and severe deficiency requires treatment with supplements.
The researchers caution that their results are not proof of cause and effect, but rather evidence of a complex interplay between low vitamin D levels and hemoglobin. Several mechanisms could account for the link between vitamin D and anemia, including vitamin D’s effects on red blood cell production in the bone marrow, as well as its ability to regulate immune inflammation, a known catalyst of anaemia.
When investigators looked at anaemia and vitamin D by race, an interesting difference emerged. Black children had higher rates of anemia compared with white children (14 percent vs. 2 percent) and considerably lower vitamin D levels overall, but their anaemia risk didn’t rise until their vitamin D levels dropped far lower than those of white children. The racial difference in vitamin D levels and anaemia suggests that current therapeutic targets for preventing or treating these conditions may warrant a further look, the researchers say.
“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“ says lead investigator Meredith Atkinson, M.D., M.H.S., a pediatric kidney specialist at the Johns Hopkins Children’s Center, USA.
Untreated, chronic anaemia and vitamin D deficiency can have wide-ranging health consequences, including organ damage, skeletal deformities and frequent fractures, as well as leading to premature osteoporosis in later life.
Atkinson M A et al., Vitamin D, Race, and Risk for Anemia in Children. The Journal of Pediatrics, 2013; DOI: 10.1016/j.jpeds.2013.08.060
Categories: Nutritional News, Children's Health