Australian researchers have discovered that many critically ill patients in intensive care are deficient in vitamin D.
A small study by researchers at the Garvan Institute of Medical Research in Sydney, has found that as many as 45% of patients in an intensive care unit were vitamin D-deficient.
The lead author of the study Dr. Paul Lee, an endocrinologist and research fellow at the Institute says the sicker the patients were, the lower their vitamin D levels and he says it is unclear whether this is just an association, or whether vitamin D deficiency itself contributes to the severity of the disease.
Vitamin D is a fat-soluble vitamin that is naturally present in only a few foods - some fish, such as salmon and tuna, cheese, egg yolks and some mushrooms - vitamin D is also found in fortified milk and cereals.
The best natural source is when sunlight strikes the skin and triggers vitamin D production in the body.
Vitamin D is essential for the body's calcium absorption in the gut and bone growth and health - a shortage of vitamin D means bones can become thin, brittle, or misshapen.
Vitamin D prevents rickets in children and osteomalacia in adults and together with calcium, helps protect older adults from osteoporosis.
Vitamin D also plays a roles in the immune system and the reduction of inflammation and some experts believe vitamin D deficiency is increasingly being linked to adverse health outcomes.
For the study, the researchers measured vitamin D levels in 42 people being treated in an intensive care unit and found almost half were vitamin D-deficient.
The researchers say three patients died during the study and it was found that they had the lowest levels of vitamin D in the study group.
Dr. Lee says that vitamin D is involved in controlling blood sugar levels, calcium levels, heart function, gastrointestinal health and in defending against infection.