Researchers have conducted essential research to uncover the non-skeletal benefits of vitamin D

Addressing current research regarding the associations of vitamin D with immune function, hypertension, stroke, skin conditions and maternal/fetal health.

Recent studies have shown that the effects of vitamin D may extend beyond bone health, but the findings in this area have remained inconsistent. Clifford Rosen, MD, of Tufts University School of Medicine set out to clarify some of these gray areas. He said: "The role of vitamin D supplementation in the prevention and treatment of chronic non-skeletal diseases remains to be determined.

"We need large randomised controlled trials and dose-response data to test the effects of vitamin D on chronic disease outcomes including autoimmunity, obesity, diabetes, hypertension and heart disease."

They made several conclusions from the study, which have been published in The Endocrine Society's Endocrine Reviews. The first finding was that skin disorders such as psoriasis could be treated by tropical and oral vitamin D. However, more trials are needed to demonstrate the efficiency of this method.

The link between obesity and vitamin D deficiency seems to have unsubstantial evidence. First of all, a cause and effect relationship has not been established, and there is also a lack of evidence to support the tenet that vitamin D supplementation reduces the risk of type 2 diabetes or the metabolic syndrome.

Results that suggest vitamin D reduces cancer incidence are also inconclusive as to causality. Although there is some strong observational evidence for colorectal cancer, there is little evidence relating to breast, prostate and total cancer.

Finally, the research concluded that there is a possibility that vitamin D supplementation may lower cardiovascular disease risk, but there are limitations in applying observational data to clinical practice. In this area, more clinical trials will be needed to support recommending vitamin D supplementation for lowering cardiovascular disease.