'Sept 10, 2010 -- Vitamin D is the new ""it"" vitamin. A number of studies link its deficiency to a host of medical conditions, including heart disease, diabetes, and certain cancers. Now, a new review article makes the case for vitamin D supplementation in the treatment of asthma. The findings appear in the September issue of the Annals of Allergy, Asthma & Immunology.
Researchers reviewed nearly 60 years' worth of literature on vitamin D status and asthma. They found that vitamin D deficiency is linked to increased airway reactivity, lower lung functions, and worse asthma control. Risk factors for vitamin D deficiency include obesity, being African-American, and living in Westernized countries, the researchers report. These are also populations known to be at higher risk for developing asthma.
Vitamin D supplementation may improve asthma control by blocking the cascade of inflammation-causing proteins in the lung, as well as increasing production of the protein interleukin-10, which has anti-inflammatory effects, the study authors suggest.'
'The next step is long-term trials that look at the effects of vitamin D supplementation in people with asthma, the study authors say.
""If we give supplemental vitamin D and measure asthma outcomes over a year, do you get better and that is the key,"" he says. ""There is a lot of circumstantial evidence, but we need to do definitive studies with vitamin D interventions to see what happens.""
Michael Holick, MD, PhD, a professor of medicine, physiology, and biophysics at the Boston University School of Medicine and the director of the Vitamin D, Skin, and Bone Research Laboratory there, thinks the jury is in regarding the role that vitamin D supplementation can and should play in treating and preventing asthma.
""This article provides strong evidence that vitamin D is altering the immune system and preventing asthma at a biochemical level,"" he says.'
'""Vitamin D ... has effects on many immune cells and we are learning more and more about the impact that it can have on allergic diseases such as asthma,"" says Pia Hauk, MD, an assistant professor of Pediatrics at National Jewish Health in Denver.
""If you have low vitamin D levels, your asthma may be worse and you may have to take more medication to control it,"" she says. But ""new research suggests that if we normalize vitamin D levels, you may need less medication to get control of the inflammation.""
This is important to many parents, she says.'