Low vitamin D linked to PAD, anemia
Low blood levels of vitamin D may contribute to the development of peripheral arterial disease (PAD), according to new findings. The incidence of PAD among those with the lowest serum levels of vitamin D was more than double that among those with the highest levels.
Researchers at the Albert Einstein College of Medicine in The Bronx, N.Y. analyzed data from 4,839 adults who had taken part in the National Health and Nutrition Examination Survey (NHANES). They found PAD in 8.1% of those with the lowest serum levels of 25-hydroxyvitamin D (25[OH]D), compared with 3.7% in those with the highest levels. (PAD was defined as an ankle-brachial index of <0.9.) Furthermore, there was a strong graded association between lower vitamin D levels and PAD, with the incidence of PAD rising 35% for each 10 ng/mL decline in 25(OH)D, even after adjusting for cardiovascular risk factors.
The findings were published online ahead of print by the American Heart Association journal Arteriosclerosis, Thrombosis, and Vascular Biology at http://atvb.ahajournals.org (accessed May 12, 2008).
In a separate study—also based on NHANES data—researchers at the University of Colorado found that higher levels of vitamin D appear to lower the risk of anemia. Each 10 ng/mL increment in 25(OH)D was associated with a 29% reduced incidence of anemia. The link persisted after adjusting for age, gender, race, and other potential confounders.
The investigators speculate that vitamin D boosts hemoglobin levels by reducing intracellular inflammation. The researchers' findings were presented at the National Kidney Foundation's recent clinical conference held in Grapevine, Tex.