Why was the study done?
Vitamin C and vitamin D insufficiency are very prevalent in hospitalized patients, and both vitamins have been linked to psychological abnormalities, including abnormal mood states. Researchers suspected that supplementation might therefore improve mood in hospital in-patients.
As distance from the equator increases, serum levels of 25-hydroxyvitamin (25-(OH)D), the storage form of vitamin D, fall during the winter months. Since fall and winter are peak seasons for colds and flu, it has been speculated that higher circulating levels of 25-(OH)D may increase resistance to infection and conversely, lower levels in the winter would increase vulnerability. The study was done to see if there was a link between circulating blood levels of 25-(OH)D and the incidence of acute viral respiratory tract infections.
Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. American Journal of Clinical Nutrition. March 2010;91(3):535-46
Why the study was done: A reduction in dietary saturated fat has generally been thought to improve cardiovascular health, and public health campaigns in most …
The study was done because the researchers thought that consumers were confused over the value of milk labelled conventional, bST-free or organically produced, and were concerned that “some consumers may perceive that this type of specialty labelling indicates differences in the quality, nutritional value, or safety of dairy foods.” They therefore examined 292 pasteurized homogenized milk samples of all three types. They focused their investigation only on the fatty acid composition of the milks.