Vitamin D is, at this point, probably one of the trendiest vitamins around. Everyone suddenly seems to be getting their vitamin D level tested (specifically vitamin D3 or 25(OH)D, also called calcidiol) and, when levels are found to be deficient, taking supplements. In November 2010, the Institute of Medicine tripled its daily recommendations for vitamin D from 200 International Units to 600 . Severe vitamin D deficiency causes rickets, which leads to a softening and weakening of the bones, so milk has been fortified with vitamin D to prevent rickets. Less dramatic vitamin D deficiency has been implicated in ailments ranging from cancer to heart disease to schizophrenia to autoimmune diseases to colds and the flu. But how does vitamin D act in the body — how can it contribute to so many different physiological processes?
Celiac disease is a genetic digestive disorder triggered by consumption of the protein gluten, which is found in bread, pasta, cookies, pizza crust and many other foods containing wheat, barley or rye. Researchers now report that there is a factor independent of diet that contributes to oxidative stress in celiac disease patients; children with celiac disease have higher than normal levels of two oxidative DNA damage biomarkers, regardless of what they eat .
Celiac disease is an autoimmune disease in which the consumption of gluten — a protein found in all forms of wheat, including spelt, kamut, semolina and triticale, as well as in barley and rye — induces an inflammatory reaction that destroys the gut. It occurs in almost 1% of the population, although in the United States as many as 97% of cases remain undiagnosed. Most autoimmune diseases are thought to be caused by an interaction between a genetic predisposition and an environmental trigger, but celiac disease is the only one for which the environmental trigger is known: gluten.
The gene Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) encodes a cytokine, a signaling molecule secreted by immune cells that has an effect on other cells and is involved in inflammation. A recent report in Cell Host and Microbe reveals that in the gut, GM-CSF helps protect against infection by a bacterial pathogen .
GM-CSF has long been known to promote the survival and differentiation of dendritic cells, immune cells that are present in small quantities in tissues that are in contact with the external environment, including the skin and the inner lining of the nose, lungs, stomach and intestines. Dendritic cells are immune modulators that originate in the bone marrow and travel through the blood and lymph to the peripheral tissues in an immature state. Once they arrive, they differentiate and function as professional “antigen presenting cells”: they alert T cells and B cells to the presence of any foreign invaders. The T and B cells then mount an immune response.